Here is a good look at another source of noise in the shack.. You need to check all of your light bulbs. Especially LEDs. They can cause RFI and all sorts of Radio Interference with AM and even short wave listening.
K4KLB Messages: 2 Registered: April 2006 Location: Suffolk, Va
If you are like me and trying to learn CW and spend a lot of time in your car, this may help you as well.
Familiarize yourself with a couple morse characters. Maybe print them out and tape them to your steering wheel if you have a hard time remembering them. As you pbass street signs on the road sound the characters in your head, tap your finger on your leg, steering wheel, whatever. As you get proficient with those characters try more characters but do not exclude what you have already learned. Pick a word or two off of a HWY sign and try it.
"Guns cause crime like spoons cause Rosie O'Donnell to be fat". - Ted Nugent
This will be used to retrofit a laptop keyboard for the Raspberry Pi or the Pine64 inside a laptop.
Touching several pins together will give you a key combinations.
These are the results so far:
25 to 10 = delete
25 to 13 = f1
24 to 7 = right arrow and 6 when numlock
24 to 10 = left arrow
24 to 13 = caps lock
24 to 14 = f3
24 to 15 delete
24 to 16 = t
24 to 17 = y
24 to 18 = ]
23 to 13 = \
23 to 8 = up
23 to 7 = delete
22 to 8 = end
22 to 13 = 2
21 to 3 = z
21 to 4 = q
21 to 5 = a
20 to 2 = /
20 to 3 = \
20 to 4 = p
20 to 5 = ;
19 to 3 = .
19 to 4 = o
19 to 5 = l
18 to 3 = ,
18 to 4 = i
18 to 5 = k
17 to 2 = n
17 to 3 = m
17 to 4 = u
17 to 5 = j
17 to 22 = 7
17 to 23 = h
17 to 24 = y
17 to 25 = 6
16 to 3 = v
16 to 4 = r
16 to 5 = f
16 to 22 = 4
16 to 23 = g
16 to 24 = t
16 to 25 = 5
16 to 2 = b
15 to 2 = space
15 to 3 = return
15 to 5 = \
14 to 3 = c
14 to 4 = e
14 to 5 = d
13 to 3 = x
13 to 4 = w
13 to 5 = s
12 to 3 = shift (probably 12 only)
11 to 3 = start menu
10 to 2 = down arrow
9 to 2 = right arrow
9 to 3 = /
9 to 4 = 8
9 to 5 = 2
10 to 4 = home
10 to 5 = end
9 to 5 = arrow down
8 to 2 = left arrow
8 to 5 = enter
8 to 4 = +
4 to 6 = right click
4 to 7 = page up
3 to 7 = *
3 to 10 = numlock
2 to 7 = -
2 to 9
1 to 2 = f10
Fixed: A disk read error occurred. Press Ctrl+Alt+Del to restart [message #3242]
Fri, 24 February 2017 14:45
kc2nda Messages: 40 Registered: December 2004 Location: New Paltz
If you cloned a hard drive from one computer the other and you have "A disk read error occurred. Press Ctrl+Alt+Del to restart", you can do all the googling you want, but you will not find the answers on any of them..
There could be a bunch of reasons for this, but in this scenario, the old hard drive was 1TB and the new was a 2TB drive. The BIOS set the Hard Drive to IDE mode. Once the BIOS was changed to AHCI, the computer booted without the Ctrl+Alt+Del to restart error.
Windows will blue screen at this point (Most likely the blue screen will be 7B) because the drivers for the controller are set to the IDE mode. You must change the controller from IDE to AHCI in the system registry. Take the drive out of the system and load the registry hive from another computer.
Open HKEY_LOCAL_MACHINE\SYSTEM registry hive
Note the value of Select\Current (NNN).
Go to registry key ControlSetNNN\Services\msahci
Go to registry key ControlSetNNN\Services\pciide
System should now boot into Windows.
The trick to this whole thing is to do this before you clone the drive! =)
Icom's PCR-1000 radio has a 9 pin serial interface for the controller. Usually this is done through a PC and software. Since the industry is going towards microcontrollers and FPGAs, I decided to make a simple controller with an FPGA to see if it was possible. The software that ICOM has is limited to what they offer. It is not open source, so modifying the software to do what you want is impossible. Watch the video for the implementation on an FPGA:
GE Profile Refrigerator Clicking Noise [message #3243]
Mon, 27 February 2017 00:03
kc2nda Messages: 40 Registered: December 2004 Location: New Paltz
Have GE Profile Refrigerator Clicking Noises? After about 6 years the water stopped coming out for no reason but would come back on once in a while. In the morning a weird whirring noise like it was not able to start would be coming out of the back. Open and close the door and it would snap back on. Almost like it was in some sort of cycle. Then finally, out of the blue, a big storm hit and the power went out for about 6 hours. Low and behold, the refrigerator decided not to come back on.
Took the cover plate to the main board off and discovered three bad capacitors on the board. The clicking is a relay that doesn't seem to have enough power to keep it going. The power on the board was being hampered by the bad capacitors. 2 caps, 470uF 25V were way off the charts and bulged and one of the 400V 47uF caps as well. The 400V cap I tested and it was leaky but still okay enough to keep in until I ordered new ones.
Popped the main board back in, and now back in business. The water now works great as well..
Hope this might help someone with their refrigerator in a jam..
The Rigol DS1052E 50MHz scope arrived and it has been sitting for about a year (I guess maybe it is out of the warranty now anyway, so time for the HACK!) We finally got around to hacking the 50MHz beast to 100MHz. The unit came shipped with 00.02.05 SP1 firmware. This was tricky because RIGOL knew about all of the hacking going on. They put a stop to downgrading the firmware with the 00.02.05 firmware version.
The only way to hack this unit is to downgrade it to the 00.02.02.02 firmware. This firmware allowed you to change the serial number and model number which changes the scope to 100MHz. To do this, you need to use a USB or Serial port with special commands. Any newer firmware than 00.02.02.02 supposedly removed this feature. The trick was to take the 00.02.02.02 firmware and change the header on the file to reflect a larger firmware version. RIGOL also obscured the firmware version in their new firmware (02.05) so it isn't as easy as changing the numbers intuitively. With the right combination and a hex editor, the firmware was patched to make the scope think that the firmware was newer, but in fact, it was the old 00.02.02.02 firmware! Nice hack that actually works!
Linux was not playing well with the serial port and USB port, so Windows was used to make the serial/model number changes. After wondering why Windows was only recognizing it as a hard drive, the option for "Computer" was found in the "I/O Setup" for "USB Device". Once that was changed to "Computer", Windows recognized the RIGOL unit and the numbers were able to be changed. I bet this was the only problem with Linux also. But the job is done and there is no need to go back to try Linux at this point.
I wonder if the hack actually increased their sales or lost them money due to everyone purchasing the same unit for half the price? I know the purchase of this particular unit was because it could be hacked to 100MHz so my opinion is they gained more business and publicity from it.
I had the same problem many people are having with the GeForce 7600 GT video cards. I had 2 x GeForce 7600 GT cards in the same machine (...running 4 monitors...). The 1500uF capacitors are all crap. They probably cheaped out on them when manufacturing. On one card I had 2 caps blown across the inductor. But I pulled all of the 1500uF 6.3V caps on the board and tested them all. ALL of them failed their leakage test. So the best thing to do on those is to replace them all. Even if they look good, replace them. The 1000uF 16V cap tested fine. Cards work great afterwards...
kc2nda Messages: 40 Registered: December 2004 Location: New Paltz
The pair of Ritron DTXM-254's arrived today. Can't wait to reverse engineer them. The first thing that was done was to TAKE THEM APART! Here is what was found:
The processor is an Atmega32 which has more I/O pins and more memory than the Atmega8. This is the central processing unit for this radio. Next to it is the MX919B which is a 4-Level Root Raised Cosine FSK Modem. This is the little guy that does most of the talking. A fine engineering job well done by Ritron.
2000 (MTS2000 FLASHPORT) SOFTWARE-FIRMWARE ANALOG SYSTEM PACKAGE R08.70 - CVN6258F, REBANDING ENABLED, REQUIRES FLASH RIB.
2000 & 2100 Series Select 5 RSS v.R02.10.00. KIT.NO. GV6011L. 11 July 1996.
2000 & 2100 Series Select 5 RSS v. R02.10.01. KIT NO. GV6011M. 17Dec1998.for:MCS2000/MTS2000.
2000 Series Factory Bypass Utility : 82A02291U01 July 03, 1996.
2000 SERIES FACTORY BYPASS UTILITY: 82A02291U03. This kit replaces 8202291U01 that only was made for test.This kit will Flash the following MCS2000 / MTS2000 radio models:
Model no Freq Power
M01KHN9PW5BN VHF 25W
M01RFN9PW5BN UHF 10W
M01RHN9PW5BN UHF 25W
H01KDH9PW1BN VHF 5W
H01KDH9AN8BN VHF 5W
H01RDH9PW1BN UHF 4W
H01RDH9PW8BN UHF 4W
already programmed with: SmartNet H37 Software and Flight Number Codeplug. User RSS: MCS2000 SDVN4337A, MTS2000 SDVN4336A to latest: Flight Number Firmware.
2100-WOOKIE-LAB- Field Programmer for the MOBIUS Radio-Series (Sky Walker) 2100 portables and mobiles radio with 5/6 Tone signalizing.
2100 Series Sky Walker RADIO UPGRADE UTILITY. SDVN4296C. 12 Jul 1996. Will do various JEDI models.
2100 Series Sky Walker RADIO UPGRADE UTILITY. 1994
2100 Series Sky Walker RADIO UPGRADE UTILITY-LAB-POL 1995.( Polish version). MOTOROLA 2100 SERIES SKYWALKER RADIO UPGRADE
MT2100 SERIES FuG RADIO BYPASS UTILITY vSDVN4357C. Upgrades the FuG radios from version 8202260u01t4 & 8202260u02 to version 8202260u03 to provide the latest features.
UTILITY R06.11.00. LAB VERSION. 07-MARCH-1995. ( NOW YOU CAN : BOOTSTRAP/PROG INTERNAL EEPROM/PROG EXTERNAL/FLASH RADIO/CHANGE MODEL NUMBER/CHANGE SERIAL NUMBER/FLASH NEW APPLICATION TO RADIO! )
PCON-PLUS-LAB- v 02.35KB-FLASHTOOL for jedi radios: saber-si/astro-p&m/spectra-ii/reneissance/closed-radios.
ROS-RADSTER-RADIO-EXERCISER-LAB- v D1.79. 22-JAN-93. for jedi radio with open architecture:mt2xxx/mtsxxx/gp1200.
ROOSTER-FOR JEDI MODELS-LAB-changes serial and model numbers-(esn), splits archives into int/ext codeplugs, hex-editor.
ASTRO-LAB- Series RSS for Portables. v.B03.04.00. 22 Sept.1993.
ASTRO SP LAB, Portables, SP03.04.01. September 20, 1998.
K2GOG Messages: 12 Registered: January 2016 Location: FN31re
Icom commercial radios can be programmed by using an OPC-478 cable used for many amateur radios by creating an adapter out of a head phone extension cable and a honey5 crimped connector. The Icom equivalent is the OPC-592
The radios that this will work for include:
IC-F320 (great for 2m)
IC-F420 (great for 70cm)
All can be found for under $50 in many cases and are all robust radios great for just a few repeaters, a link radio, APRS or packet gateway.
Software is mostly DOS based and will recognize a USB to serial adapter or you can make the same adapter as above for universal cables used for Chinese import radios like a Baofeng
RJ-45 Pin 2 goes to "ring" on 3.5mm. RJ-45 Pin 7 goes to "ground" on 3.5mm. Make sure you do not short any other pins in the RJ-45 or it will not work. This adapter I created is the same thing as an Icom OPC-592.
Motorola XPR 4550 XPR 5550 Programming Cable Pinout
This needs a simple USB cable with no other parts involved besides the PMLN5072 connector. Cut the one side of the USB cable that is not needed. Wire up as follows:
White Data - Pin 2
Green Data + Pin 1
Red Vbus Pin 3
Black ground Pin 4
Looking at the back of the radio the connector facing you the pins are as follows:
Upper left side of the connector is pin 2
Lower left side of the connector is pin 1
Pin 4 is next to pin 2
Pin 3 is next to pin 1
Some people have mentioned that the green and white wires where swapped, so you might want to check your USB connector before making the assumption that the white and green wires are what they really say they are. Some cables may be swapped depending on who made them. Some cheap cables might not follow the standard color scheme.
I was told by a Motorola rep that the front microphone connector will not program everything on the radio and is not recommended because it is some proprietary system Motorola has. However the back will program everything.
The left cable is the one just made for under $10. The one on the right was purchased by another ham for more than $30. These cables sell on ebay for as much as $60. It gives a reason to cut off USB cables from old mice and keyboards and keep them around for cables like these.
motorolaxtl Messages: 1 Registered: April 2013 Location: Australia
Hi everybody I new to this site I recently bought a Motorola mcs2000 and I took it to a Motorola dealer in Australia and they told me that they used ver 2.00.00 software to read the radio Iam wondering if anybody has that software. Thank you in advance.
Raspberry Pi Doesn't Boot after Pulling SD card Out While Booting [message #3236]
Tue, 20 December 2016 01:42
kc2nda Messages: 40 Registered: December 2004 Location: New Paltz
I have pulled out the SD card of a Raspberry Pi quite often when it is booting. It is not something that is recommended. Most of the time it will boot again. But there is that occasion when the SD card will be marked as dirty and will not boot. Both the green and red LEDs will be on and the pi will not boot.
Turn off the Pi if it is not off already, take the card out and put it in another linux system. Make sure you unmount the SD card.
Issue the fdisk command to see what device the SD card is:
You will probably see something like:
/dev/mmcblk0p1 ................. FAT32 (LBA) (This will be the boot device
/dev/mmcblk0p2 ................. Linux (data)
Take out the SD card when done and the Pi should boot again...
This is a very nice circuit and does an excellent job. The instructions were very good and easy to follow. However the instructions on how to get it working and how to setup a radio and add all of the necessary next steps are not.
This first one took a few hours to put together. Testing it was the hard part. A Motorola radio was used to test the TNC. A serial to Motorola cable was constructed.
The Raspberry pi was setup and all of the necessary packages configured.
The TNC only transmitted once. From then on, there were problems.
Two other TNC-PI's kits were delivered for a local club to be assembled. Out of the two, one of these TNC-PI's actually worked. But not always. They were very sporadic.
After closer examination, the TNC-PIs were found to have poor through hole connections. You HAVE TO make sure that anything using a through hole was soldered on BOTH SIDES.
IMPORTANT!!! This will be repeated again: MAKE SURE BOTH SIDES OF ANY PARTS THAT CAN BE SOLDERED ON BOTH SIDES, ARE SOLDERED ON BOTH SIDES!
After close inspection, if the soldering iron is NOT left connected for a little longer than normal and the solder does NOT reach through to the other side and actually flow to the other side, this board will NOT function properly!
Please check the top of the board and look at all solder joints. Especially under the sockets for the IC's.
All three boards were inspected, re-soldered on both sides and they all worked perfect.
Kernel Panic : VFS :Unable to mount root fs on unknown-block [message #3207]
Sat, 06 February 2016 18:32
kc2nda Messages: 40 Registered: December 2004 Location: New Paltz
Kernel Panic : VFS :Unable to mount root fs on unknown-block
This will happen if your memory card is corrupt. It could be an issue if the PI has been shutdown improperly or if the card is going bad.
If you have data on the card, don't get too worried yet. Get another card and boot from the PI using another card. Once the filesystem is booted, find a USB card reader, put the bad card in the card reader and find out what the card name is:
There are several ways to do this. A simple df will show you the OS that is booted and you should see the other card which would be something like sda1
run this command:
sudo fsck.ext4 -fy /dev/sda1
It should fix the card. Then it should boot. Most likely it will have to run through a lot of error checking and fsck should autorun. Be patient... Worked great for me for the FIRST time in a few years using the PI that this has happened..
This Raspberry Pi Solar Heater Controller project took quite some time to finish. The box design was built around a piece of solar glass that was meant for solar panels at one point. The glass is tempered and when breaks, will shatter into a million little pieces. (I broke only 2 so far, but enough to not want to break them again!)
Yes, these are Coors Light beer cans.. and NO, I did not drink them. I did buy them for .05 a piece though from someone very nice enough to collect them for me! If this isn't REAL recycling..
4 Inch Holes were drilled into the house. One on the top for hot air out, and one for intake on the bottom. The cold air from the floor will be sucked in and heated through the tubes. Once the box reaches a certain temperature, the fan will turn on and force the hot air into the room. (Yes, the back of the house needs to be painted.. The ivy grows like mad, and when you pull it off, it takes the paint with it.)
The Raspberry Pi and the relay board and fan controller all were put on the right side of this box. Inside this box is a solar charge controller and breakers. The battery is a 12V marine.
The "1 Wire" DS18B20 temperature sensors Were hooked up to the GPIO pins in this fashion:
The brain of this whole system is powered by the Raspberry Pi. The system is using the PiFace for the relays and a Buck converter to convert the voltage from 12V to 5V. There is also a simple motor controller with a "manual" potentiometer for adjusting the fan speed. (The next enhancement to this will be an electronically controller fan speed module.. I was working on this but never finished.)
The Raspberry Pi is setup as a database/web server and it will take the temperature measurements of the inside and outside of the box and will insert them into a database. This way, at any given time (within 10 minute increments), we can see the status. The data can also be compared throughout the years. The Python scripts monitor the date/time and the temperatures to determine if the fan needs to be working or not. So far the system has been running for more than two years without any problems and OFF THE GRID! The average temperature stays at about 70 degrees in the room with no other heating needed. This can probably be tweaked a bit, but during negative degree weather outside, 70 degrees isn't bad!
If the fan isn't running, the box can reach temperatures of up to 160 degrees in the middle of winter!
Some future additions might be to add alarm indexes and a camera to take snapshots of specific events. These events can help to facilitate changes to efficiency.
So far this system has been running for over a year with no issues (10/26/2015)
I ordered my boards from Travis and they came in within a few days! Thanks Travis! The boards were very well made and worth every penny. Mounting the SMD chips wasn't too bad either. The first row I soldered on the main M430F2618 chip ended up with a couple of crossed pins because I moved the soldering iron in the wrong direction and it bent a pin.. (I don't have brain surgery hands anymore.. These pins are generic IO pins and they weren't being used, so I just left them. I don't think anyone will notice except for me and even though it bothers me, it works fine and it isn't worth the time to try to separate them.
As for the programming of the firmware, this was a little tricky. At first I was using Windows with Cygwin and I had nothing but problems with the make install.
I wrote this post to help others who may have run into similar problems with their GoodFET programming.
I had my Raspberry Pi handy and decided to use this to do the firmware programming. Once hooked up, python-serial needed to be installed. (Python was already installed prior to this, if it isn't installed, it should be..)
#Make sure the GoodFET device is the correct device. You can find this by looking in /dev/ . You can do an ls on the /dev/ directory with it unplugged, then plugged in. Whatever shows up when plugged in should be what is used (ex: ttyUSB0)
sudo apt-get install binutils-msp430 gcc-msp430 msp430-libc mspdebug
sudo apt-get python-serial
git clone https://github.com/travisgoodspeed/goodfet goodfet
#This next line's lohoneyion has changed from the original documentation and the make is in this dir.
#This next line shows another change. The .bsl file is in a different spot now also (under client dir).
../client/goodfet.bsl --speed=38400 -e -p goodfet.hex
Output should look something similar to this:
MSP430 Bootstrap Loader Version: 1.39-goodfet-8
Transmit default password ...
Current bootstrap loader version: 2.13 (Device ID: f26f)
Checking for info flash... Saved!
Transmit default password ...
Transmit default password ...
Current bootstrap loader version: 2.13 (Device ID: f26f)
Changing baudrate to 38400 ...
25720 bytes programmed.
#Run a self-test (this takes a minute or more)
Performing monitor self-test.
stepnjump Messages: 1 Registered: October 2010 Location: Montreal
I have a lot of pagers. they are all on the same frequency. Years ago, it used to be cheaper to have them all on the group call than now. Now it costs even more to have them on group call than if they were all on separate phone numbers!
Would any of you know if there would be a way to have them all again on the same cap-code or clone them so that once I page one beeper, they would all ring?
Theory/Maintenance Manual: 6881033C65
Tone Alert/Silent Alert Service Manual, VHF: 6881032C55
Tone Alert/Silent Alert Service Manual, Low-band VHF: 6881032C75
Tone and Voice Service Manual, VHF: 6881032C50
Tone and Voice Service Manual, Low-band VHF: 6881032C60
The following summary describes the coding used on POCSAG pager
signals and may be of interest to those curious about what those ear-splitting
beeps and buzzes mean and how they encode data. This summary is
based on a very old text of the standard from my files; the current
text of the POCSAG standard is available as CCIR Radiopaging Format 1.
Note that some current POCSAG signals (so called Super-POCSAG)
transmit paging at 1200 or 2400 baud instead of the 512 baud I refer to
here, but use essentially a similar coding standard.
The interested USA reader is reminded that willfully intercepting
other than tone only paging is a violation of the ECPA with similar
penalties and criminal status to willfully intercepting cellular phone calls.
The interested reader is advised that at least two of Universal
Shortwave's RTTY reading devices (the M8000 and the new C-400) are
capable of reading at least the older 512 baud version of POCSAG paging,
so commercial devices for this purpose are currently being sold in
And finally, much alphanumeric paging - particularly that installed
some time ago, uses a proprietary Motorola encoding format called
GOLAY which is quite different from POCSAG. The two can be told apart
by their baud rates - GOLAY is 600 baud.
First POCSAG stands for Post Office Code Standarization Advisory
Group. Post office in this context is the British Post Office
which used to be the supplier of all telecommunihoneyions services in
England before privatization.
POCSAG as defined in the standard, (original POCSAG) is 512 bits
per second direct FSK (not AFSK) of the carrier wave with +- 4.5 khz shift
(less deviation than that is used in some US systems). Data is
NRZ coded with the higher frequency representing 0 (space) and the
lower one representing 1 (mark).
The basic unit of data in a POCSAG message is the codeword which
is always a 32 bit long entity. The most significant bit of a codeword
is transmitted first followed immediately by the next most significant
bit and so forth. The data is NRZ, so that mark and space values (plus
and minus voltages) as sampled on the output of the receiver
discriminator at a 512 hz rate corrospond directly to bits in the
codeword starting with the MSB. (Note that the audio output circuitry
following the discriminator in a typical voice scanner may considerably
distort this square wave pattern of bits, so it is best to take the
signal directly off the discriminator before the audio filtering).
The first (msb) bit of every POCSAG codeword (bit 31) indihoneyes
whether the codeword is an address codeword (pager address) (bit 31 = 0)
or a message codeword (bit 31 = 1). The two codeword types have
have different internal structure.
Message codewords (bit 31 = 1) use the 20 bits starting at bit
30 (bit 30-11) as message data. Address codewords (bit 31 = 0) use 18
bits starting at bit 30 as address (bits 30-13) and bits 12 and 11 as
function bits which indihoneye the type and format of the page. Bits 10 through
1 of both types of codewords are the bits of a BCH (31,21) block ECC
code computed over the first 31 bits of the codeword, and bit 0
of both codeword types is an even parity bit.
The BCH ECC code used provides a 6 bit hamming distance between
all valid codewords in the possible set (that is every valid 32 bit
codeword differs from ever other one in at least 6 bits). This makes
one or two bit error correction of codewords possible, and provides
a robust error detection capability (very low chance of false pages).
The generating polynomial for the (31,21) BCH code is x**10 + x**9
+ x**8 + x**6 + x**5 + x**3 + 1.
Codewords are transmitted in groups of 16 (called batches), and
each batch is preceeded by a special 17th codeword which contains a
fixed frame synchronization pattern. At least as of the date of the
spec I have, this sync magic word was 0x7CD215D8.
Batches of codewords in a transmission are preceeded by a start
of transmission preamble of reversals (10101010101 pattern) which must
be at least 576 bits long. Thus a transmission (paging burst) consists
of carrier turnon during which it is modulated with 512 baud reversals
(the preamble pattern) followed by at least 576/512 seconds worth of
actual preamble, and then a sync codeword (0x7CD215D8), followed by 16
data/address codewords, another sync codeword, 16 more data/address
codewords and so forth until the traffic is completely transmitted. As
far I am aware there is no specified postamble. I beleive that all 16
of the last codewords of a transmission are always sent before the
carrier is shut off, and if there is no message to be sent in them the
idle codeword (0x7A89C197) is sent. Later versions of the standard may
have modified this however.
In order to save on battery power and not require that a pager
receive all the bits of an entire transmission (allowing the receiver
to be turned off most of the time, even when a message is being transmitted
on the channel) a convention for addressing has been incorperated which
splits the pager population into 8 groups. Members of each group
only pay attention to the two address code words following the synch
codeword of a block that corrospond to their group. This means that
as far as addressing is concerned, the 16 codewords in a batch are
divided into 8 frames of two codewords apiece and any given pager
pays attention only to the two in the frame to which it assigned.
A message to a pager consists of an address codeword in the
proper two codeword frame within the batch to match the recipients frame
assignment (based on the low three bits of the recipient's 21 bit
effective address), and between 0 and n of the immediately following
code words which contain the message text. A message is terminated by
either another address code word or an idle codeword. Idle codewords
have the special hex value of 0x7A89C197. A message with a long text
may potentially spill over between two or more 17 codeword batches.
Space in a batch between the end of a message in a transmission and
either the end of the batch or the start of the next message (which of
course can only start in the two correct two codeword frame assigned to
the recipient) is filled with idle codewords. A long message which
spills between two or more batches does not disrupt the batch structure
(sync codeword and 16 data/address code words - sync code word and
16 data/address codewords and so forth) so it is possible for a pager
not being addressed to predict when to next listen for its address and
only turn on it's receiver then.
The early standard text I have available to me specifies a 21 bit
address format for a pager (I beleive this has been extended since)
with the upper 18 bits of a pager's address mapping into bits
30-13 of the address codeword and the lower 3 bits specifiying which
codewords within a 17 codeword batch to look at for possible messages.
The address space is further subdivided into 4 different message classes
as specified by the function bits (bits 12 and 11 of a codeword). These
address classes corrospond to different message types (for example
bits 12 and 11 both zero indihoneye a numeric message encoded in 4 bit BCD,
whilst bits 12 and 11 both set to 1 indihoneye an alpha message encoded
in 7 bit ASCII). It was apparently envisioned that a given pager could
have different addresses for different message types.
There are two message coding formats defined for the text of messages,
BCD and 7 bit ASCII. BCD encoding packs 4 bit BCD symbols 5 to a codeword
into bits 30-11. The most significant nibble (bits 30,29,28,27) is the
leftmost (or most significant) of a BCD coded numeric datum. Values beyond 9
in each nibble (ie 0xA through 0xF) are encoded as follows:
0xA Reserved (probably used for something now - address extension ?)
0xB Character U (for urgency)
0xC " ", Space (blank)
0xD "-", Hyphen (or dash)
0xE ")", Left bracket
0xF "(", Right bracket
BCD messages are space padded with trailing 0xC's to fill the codeword.
As far as I know there is no POCSAG specified restriction on length but
particular pagers of course have a fixed number of characters in their
Alphanumeric messages are encoded in 7 bit ASCII characters packed
into the 20 bit data area of a message codeword (bits 30-11). Since four
seven bit characters are 21 rather than 20 bits and the designers of the
standard did not want to waste transmission time, they chose to pack the
first 20 bits of an ASCII message into the first code word, the next
20 bits of a message into the next codeword and so forth. This means
that a 7 bit ASCII character of a message that falls on a boundary can
and will be split between two code words, and that the alignment of character
boundaries in a particular alpha message code word depends on which code
word it is of a message. Within a codeword 7 bit characters are packed
from left to right (MSB to LSB). The LSB of an ASCII character is sent
first (is the MSB in the codeword) as per standard ASCII transmission
conventions, so viewed as bits inside a codeword the characters are
ASCII messages are terminated with ETX, or EOT (my documentation
on this is vague) and the remainder of the last message codeword is
padded to the right with zeros (which looks like some number of NULL
characters with the last one possibly partial (less than 7 bits)).
The documentation I have does not specify how long a ASCII
message may be, but I suspect that subsequent standards have probably
addressed the issue and perhaps defined a higher level message protocol
for partitioning messages into pieces. The POCSAG standard clearly
does seem to allow for the notion of encoding messages as mixed
strings of 7 bit alpha encoded text and 4 bit BCD numerics, and it
is at least possible that some pagers and paging systems use this
to reduce message transmission time (probably by using some character
other than ETX to delimit a partial ASCII message fragment).
Screaming through the electromagnet swamp we live in are hundreds of
thousands of messages of varying degrees of importance. Doctors,
police, corporate executives, housewives and drug dealers all find
themselves constantly trapped at the mercy of a teeny little box:
Everyone has seen a pager; almost everyone has one. Over 20 million
pagers are on the streets in the US alone, sorting out their particular
chunk of the radio-spectrum. Another fifty-thousand more are
put into service each day.
But what the hell are these things really doing? What more can we
do with them than be reminded to call mom, or to "pick up dry-cleaning?"
** PROTOCOLS **
Pagers today use a variety of signalling formats such as POCSAG, FLEX
and GOLAY. The most common by far is POCSAG (Post Office Standardization
Advisory Group), a standard set by the British Post Office and adopted
world-wide for paging.
POCSAG is transmitted at three transmission rates--512, 1200 and 2400 bps.
Most commercial paging companies today use at least 1200, although many
companies who own their own paging terminals for in-house use transmit
at 512. Nationwide carriers (SkyTel, PageNet, MobileComm, etc.) send
the majority of their traffic at 2400 to make the maximum use of
their bandwidth. In other words, the faster they can deliver pages,
the smaller their queue of outgoing pages is. Although these
carriers have upgraded their equipment in the field to broadcast at
2400 (or plan to do so in the near future), they still send out
some pages at 1200 and 512 to accommodate their customers with older
pagers. Most 512 and 1200 traffic on the nationwide services is
numeric or tone-only pages.
POCSAG messages are broadcast in batches. Each batch is comprised of 8
frames, and each frame contains two codewords separated by a
"synchronization" codeword. A message can have as many codewords
as needed to deliver the page and can stretch through several batches
if needed. The end of a complete message is indicated by a "next address"
codeword. Both addressing and user data are sent in the codewords, the
distinction being the least significant bit of the codeword:
0 for address data, and 1 for user-data.
Standard alphanumeric data is sent in a seven-bit format, with each codeword
containing 2 6/7 characters. A newer 8-bit alphanumeric format is
implemented by some carriers which allow users to send data such as
computer files, graphics in addition to regular alphanumeric messages.
The 8 bit format allows for 2.5 characters per codeword.
Numeric data is 4 bit, allowing up to 5 numbers to be transmitted per
codeword. Tone and voice pages contain address information only.
(NOTE: Pager data uses BCH 32,21 for encoding. I don't imagine
very many of you will be trying to decode pager data by building your
own decoders, but for those of you who may, take my interpretation
of POCSAG framing with a grain of salt, and try to dig up the
actual POCSAG specs.)
** THE PAGING RECEIVER **
Paging receivers come in hundreds of shapes and sizes, although the vast
majority are manufactured by Motorola. Numeric pagers comprise over
fifty percent all pagers in use. Alphanumeric comprises about thirty
percent, with tone and voice pagers making up the remainder.
Pagers are uniquely addressed by a capcode. The capcode is usually six
to eight digits in length, and will be printed somewhere on the pager
itself. Many pager companies bassign customers PIN numbers, which are
then cross-referenced to a given capcode in databases maintained by
the service provider. PIN numbers have no other relationship
to the capcode.
Tone pagers are by far the most limited paging devices in use.
When a specified number has been called, an address only message
is broadcast, which causes the intended receiver to beep. Wow.
Tone pagers usually have 4 capcodes, which can correspond to
different locations to call back. Voice pagers are similar, except
they allow the calling party to leave a 15 to 30 second message.
The voice message is broadcast immediately after the capcode of the
receiver, which unsquelches the device's audio.
Numeric pagers, although seemingly limited by their lack of display
options have proven otherwise by enterprising users. Most numeric
data sent is obviously related to phone numbers, but numerous users
have developed codes relating to various actions to be carried out
by the party being paged. The most prolific users of this have
been the Chinese who have one of the most active paging networks
in the world. I suppose the next biggest users of code-style numeric
paging would be drug dealers. (2112 0830 187 -- get to the fudgeing
drop site by 8:30 or I'll bust a cap in your bass!)
Alphanumeric pagers are most often contacted through a dedicated
service that will manually enter in the message to be sent onto the
paging terminal. One such service, NDC, offers its phone-answering
and message typing services to various pager companies. Next time
you are talking to a pager operator, ask him or her if they are at
NDC. They probably are.
In addition to the capcode, pagers will have an FCC ID number, a serial
number, and most importantly, the frequency that the device has been
crystaled for imprinted on the back of the device. Although technology
exists that would allow pagers to listen on a number of frequencies
by synthesizing the frequency rather than using a crystal, pager
manufacturers stick to using crystals to "keep the unit cost down."
Pagers may have multiple capcodes by which they can be addressed by.
Multiple capcodes are most often used when a person has subscribed to
various services offered by their provider, or when the subscriber is
part of a group of individuals who will all need to receive the same
page simultaneously (police, EMTs, etc.).
Most low-cost pagers have their capcode stored on the circuit board
in a PAL. Most paging companies will completely exchange pagers
rather than remove and reprogram the PAL, so I don't think
it's worth it for any experimenter to attempt. However, like most
Motorola devices, many of their paging products can be reprogrammed
with a special serial cable and software. Reprogramming software
is usually limited to changing baud rates, and adding capcodes.
Additionally, some units can be reprogrammed over the air by the
service provider. Using a POCSAG feature known as OTP (over the air
programming) the service provider can instruct the paging receiver to
add capcodes, remove capcodes, or even shut itself down in the case
** SERVICES **
With the growing popularity of alphanumeric pagers, many service providers
have decided to branch out into the information business. The most
common of these services is delivery of news headlines. Other services
include stock quotes, airline flight information, voice mail and
fax reception notification, and email. Of course, all of these services
are available for a small additional monthly premium.
Email is probably the single coolest thing to have sent to your
alpha pager. (Unless you subscribe to about a zillion mailing lists)
Companies like SkyTel and Radiomail give the user an email address
that automatically forwards to your paging device.
IE: PIN-NUMBER@skymail.com. Several packages exist for forwarding
email from a UNIX system by sending stripping down the email to
pertinent info such as FROM and SUBJECT lines, and executing a script
to send the incoming mail out via a pager terminal data port.
One such program is IXOBEEPER, which can be found with an archie
Radiomail's founder, (and rather famous ex-hacker in his own right - go
look at ancient ComputerWorld headlines), Geoff Goodfellow had devised
such a method back in the late 70's. His program watched for incoming
email, parsed the mail headers, and redirected the FROM and SUBJECT
lines to his alphanumeric pager. Obviously, not many people had
alphanumeric pagers at all, much less email addresses on ARPANET
back in the 70's, so Geoff's email pager idea didn't see much
wide-spread use until much later.
Two RFC's have been issued recently regarding paging and the Internet.
RFC 1568, the Simple Network Paging Protocol, acts similarly to SMTP.
Upon connecting to the SNPP port the user issues commands such as:
PAGE followed by pager telephone number
MESS followed by the alpha or numeric message
RFC 1568 has met with some opposition in the IETF, who don't consider
it worthwhile to implement a new protocol to handle paging, since it
can be handled easily using other methods.
The other RFC, number 1569, suggests that paging be addressed in a rather
unique manner. Using the domain TPC.INT, which would be reserved for
services that necessitate the direct connection to The Phone Company,
individual pagers would be addressed by their individual phone numbers.
Usernames would be limited to pager-alpha or pager-numeric to represent
the type of pager being addressed. For example, an alpha-page being sent to
1-800-555-1212 would be sent as email@example.com.
** PAGING TERMINAL DATA PORTS **
Many services offer modem connections to pager terminals so that
computer users can send pages from their desks using software packages
like WinBeep, Notify! or Messenger. All of these services connect to
the pager terminal and speak to it using a protocol known as
Upon connection, a pager terminal identifies itself with the following:
(I bet you always wondered what the hell those systems were)
Paging terminals default to 300 E71, although many larger companies
now have dialups supporting up to 2400.
Many such systems allow you to manually enter in the appropriate information
by typing a capital "M" and a return at the ID= prompt. The system will then
prompt you for the PIN of the party you wish to page, followed by a prompt
for the message you wish to send, followed by a final prompt asking if you
wish to send more pages. Not every pager terminal will support a manual
entry, but most do.
All terminals support the IXO protocol. As there are far too many
site specific examples within the breadth of IXO, we will concentrate on
the most common type of pager services for our examples.
[ Sample IXO transaction of a program sending the message ABC to PIN 123
gleened from the IXOBeeper Docs ]
Pager Terminal YOU
Processing - Please Wait
The checksum data came from:
STX 000 0010
1 011 0001
2 011 0010
3 001 0011
A 100 0001
B 100 0010
C 100 0011
ETX 000 0011
1 0111 1011
1 7 ; Get it? Get an ASCII chart and it will all make sense.
Note: Everything in the paging blocks, from STX to ETX inclusive are used
to generate the checksum. Also, this is binary data, guys...you can't
just type at the ID= prompt and expect to have it recognized as IXO.
It wants specific BITS. Got it? Just checking...
** PAGER FREQUENCIES - US **
[Frequencies transmitting pager information are extremely easy to
identify while scanning. They identify each batch transmission
with a two-tone signal, followed by bursts of data. People with
scanners may tune into some of the following frequencies to
familiarize themselves with this distinct audio.]
Austria 162.050 - 162.075 T,N,A
Australia 148.100 - 166.540 T,N,A
411.500 - 511.500 T,N,A
Canada 929.025 - 931-975 T,N,A
138.025 - 173.975 T,N,A
406.025 - 511.975 T,N,A
China 152.000 - 172.575 N,A
Denmark 469.750 N,A
Finland 450.225 T,N,A
146.275 - 146.325 T,N,A
France 466.025 - 466.075 T,N,A
Germany 465.970 - 466.075 T,N,A
Hong Kong 172.525 N,A
Indonesia 151.175 - 153.050 A
Ireland 153.000 - 153.825 T,N,A
Italy 466.075 T,N,A
Japan 278.1625 - 283.8875 T,N
Korea 146.320 - 173.320 T,N,A
Malaysia 152.175 - 172.525 N,A,V
Netherlands 156.9865 - 164.350 T,N,A
New Zealand 157.925 - 158.050 T,N,A
Norway 148.050 - 169.850 T,N,A
Singapore 161.450 N,A
Sweden 169.8 T,N,A
Switzerland 149.5 T,N,A
Taiwan 166.775 N,A
Thailand 450.525 N,A
172.525 - 173.475 N,A
UK 138.150 - 153.275 T,N,A
454.675 - 466.075 T,N,A
T = Tone
N = Numeric
A = Alphanumeric
V = Voice
** INTERCEPTION AND THE LAW **
For many years the interception of pages was not considered an
invasion of privacy because of the limited information provided
by the tone-only pagers in use at the time. In fact, when
Congress pbassed the Electronic Communications Privacy Act in 1986
tone-only pagers were exempt from its provisions.
According to the ECPA, monitoring of all other types of paging signals,
including voice, is illegal. But, due to this same law, paging
transmissions are considered to have a reasonable expectation to
privacy, and Law Enforcement officials must obtain a proper court
order to intercept them, or have the consent of the subscriber.
To intercept pages, many LE-types will obtain beepers programmed with
the same capcode as their suspect. To do this, they must contact
the paging company and obtain the capcode bassociated with the person
or phone number they are interested in. However, even enlisting
the bassistance of the paging companies often requires following
proper legal procedures (warrants, subpoenas, etc.).
More sophisticated pager-interception devices are sold by a variety
of companies. SWS Security sells a device called the "Beeper Buster"
for about $4000.00. This particular device is scheduled as
a Title III device, so any possession of it by someone outside
a law enforcement agency is a federal crime. Greyson Electronics
sells a package called PageTracker that uses an ICOM R7100
in conjunction with a personal computer to track and decode pager
messages. (Greyson also sells a similar package to decode
AMPS cellular messages from forward and reverse channels called
For the average hacker-type, the most realistic and affordable option
is the Universal M-400 decoder. This box is about 400 bucks and
will decode POCSAG at 512 and 1200, as well as GOLAY (although I've never
seen a paging service using GOLAY.) It also decodes CTCSS, DCS, DTMF,
Baudot, ASCII, SITOR A & B, FEC-A, SWED-ARQ, ACARS, and FAX. It
takes audio input from any scanners external speaker jack, and
is probably the best decoder available to the Hacker/HAM for the price.
Output from the M400 shows the capcode followed by T, N or A (tone, numeric
or alpha) ending with the message sent. Universal suggests hooking
the input to the decoder directly to the scanner before any de-emphasis
circuitry, to obtain the true signal. (Many scanners alter the audio
before output for several reasons that aren't really relevant to this
article...they just do. )
Obviously, even by viewing the pager data as it streams by is of little
use to anyone without knowing to whom the pager belongs to. Law Enforcement
can get a subpoena and obtain the information easily, but anyone else
is stuck trying to social engineer the paging company. One other alternative
works quite well when you already know the individuals pager number,
and need to obtain the capcode (for whatever reason).
Pager companies will buy large blocks in an exchange for their customers.
It is extremely easy to discover the paging company from the phone number
that corresponds to the target pager either through the RBOC or by paging
someone and asking them who their provider is when they return your call.
Once the company is known, the frequencies allocated to that company
are registered with the FCC and are public information. Many CD-ROMs
are available with the entire FCC Master Frequency Database.
(Percon sells one for 99 bucks that covers the whole country -
716-386-6015) Libraries and the FCC itself will also have this information
With the frequency set and a decoder running, send a page that will be
incredibly easy to discern from the tidal wave of pages spewing
forth on the frequency. (6666666666, THIS IS YOUR TEST PAGE, etc...)
It will eventually scroll by, and presto! How many important people
love to give you their pager number?
** THE FUTURE **
With the advent of new technologies pagers will become even more
present in both our businesses and private lives. Notebook computers
and PDAs with PCMCIA slots can make use of the new PCMCIA pager cards.
Some of these cards have actual screens that allow for use without the
computer, but most require a program to pull message data out. These
cards also have somewhat large storage capacity, so the length of
messages have the option of being fairly large, should the service
provider allow them to be.
With the advent of 8-bit alphanumeric services, users with PCMCIA pagers
can expect to receive usable computer data such as spreadsheet
entries, word processing documents, and of course, GIFs. (Hey, porno
entrepreneurs: beeper-porn! Every day, you get a new gif sent to your
pagecard! Woo Woo. Sad thing is, it would probably sell.)
A branch of Motorola known as EMBARC (Electronic Mail Broadcast to A
Roaming Computer) was one of the first to allow for such broadcasts.
EMBARC makes use of a proprietary Motorola protocol, rather than
POCSAG, so subscribers must make use of either a Motorola NewsStream
pager (with nifty serial cable) or a newer PCMCIA pager. Messages are
sent to (and received by) the user through the use of special client
The software dials into the EMBARC message switch accessed through
AT&T's ACCUNET packet-switched network. The device itself is used
for authentication (most likely its capcode or serial number)
and some oddball protocol is spoken to communicate with the switch.
Once connected, users have the option of sending a page out, or
retrieving pages either too large for the memory of the pager, or
from a list of all messages sent in the last 24 hours, in case the
subscriber had his pager turned off.
Additionally, the devices can be addressed directly via x.400
addresses. (X.400: The CCITT standard that covers email address
far too long to be worth sending anyone mail to.) So essentially,
any EMBARC customer can be contacted from the Internet.
MTEL, the parent company of the huge paging service SkyTel, is
implementing what may be the next generation of paging technologies.
This service, NWN, being administrated by MTEL subsidiary Destineer,
is most often called 2-way paging, but is more accurately Narrowband-PCS.
The network allows for the "pager" to be a transceiver. When a page
arrives, the device receiving the page will automatically send back
an acknowledgment of its completed reception. Devices may also
send back some kind of "canned response" the user programs. An example
might be: "Thanks, I got it!" or "Why on Earth are you eating up my
allocated pages for the month with this crap?"
MTEL's service was awarded a Pioneers Preference by the FCC, which gave them
access to the narrowband PCS spectrum before the auctions. This is a big
deal, and did not go unnoticed by Microsoft. They dumped cash into the
network, and said the devices will be supported by Chicago. (Yeah,
along with every other device on the planet, right? Plug and Pray!)
The network will be layed out almost identically to MTEL's existing paging
network, using dedicated lines to connect towers in an area to a central
satellite up/downlink. One key difference will be the addition of
highly somewhat sensitive receivers on the network, to pick up the ACKs
and replies of the customer units, which will probably broadcast at
about 2 or 3 watts. The most exciting difference will be the
speed at which the network transmits data: 24,000 Kbps. Twenty-four
thousand. (I couldn't believe it either. Not only can you get your
GIFs sent to your pager, but you get them blinding FAST!) The actual
units themselves will most likely look like existing alphanumeric pagers
with possibly a few more buttons, and of course, PCMCIA units will
be available to integrate with computer applications.
Beyond these advancements, other types of services plan on offering
paging like features. CDPD, TDMA & CDMA Digital Cellular and ESMR
all plan on providing a "pager-like" option for their customers.
The mere fact that you can walk into a K-Mart and buy a pager
off a rack would indicate to me that pagers are far to ingrained into
our society, and represent a wireless technology that doesn't scare
or confuse the yokels. Such a technology doesn't ever really go away.
** BIBLIOGRAPHY **
Kneitel, Tom, "The Secret Life of Beepers," _Popular Communications_,
p. 8, July, 1994.
You do not have a problem let me explain how POCSAG is encoded so that you
can understand why you are getting these results................
00000000000000000011101101001001 Cap Code 8 seen as 32 bits- Alphanumeric
In the example above the MSB is the bit on the left and is called bit 32.
bit 32 is a zero if the codeword is a cap code and a 1 if it is data.
bit 31 to bit 14 is where the Capcode is placed, the lower 3 bits of the
capcode are discarded and not sent (I will explain why in a moment)
bits 13 and 12 are the function bits setting the page as
Alphanumeric/Numeric/Tone one/Tone two.
bits 11 to 2 are a CRC (Cyclic Redundency Checksum) this can be used to
correct up to 2 bit errors in the sent data. (This is a huge subject in its
bit 1 is an even parity bit.... if all the bits that are a 1 in the codeword
add up to an uneven number then this bit is set to one, if not then its set
POCSAG data is sent as 32 bit codewords and after 16 codewords have been
sent then a syncronization codeword is sent and then another 16 codewords
and then another syncronization codeword and so on and so on.
Each 16 codewords is called a FRAME.
The Frame is further split into double codewords, that gives us a total of 8
pairs of codewords....... now if you remember we dropped the last 3 bits of
the CAP code..... 3 bits gives us a number from 0 to 7...... 0 to 7 is eight
Because we dropped these 3 bits it means that pager 7 wil have the same
codeword value as pager 0 and pager 1 and pager 2 etc etc.
So in order to make sure that each pager only gets the pages its meant to
get what we do is to send pager zero's capcode and message in the first
double pair after a syncronization codeword and pager one's capcode and
message in the second double pair after a syncronization codeword...... etc
So to recap.........
If you enter the Cap code 8, then the first thing my PE software does is to
convert it to 1....... If you enter a Cap code of 9 then that is also
converted to 1....... infact all capcodes from 8 to 16 are all converted
into 1...... but when they are transmitted they are sent at different points
in time.... the point in time that a page is sent decides its value for the
lower 3 bits that we discarded.
So Cap Codes 0 to 7 have a POCSAG codeword of 0
So Cap Codes 8 to 15 have a POCSAG codeword of 1
So Cap Codes 16 to 24 have a POCSAG codeword of 2
And so on..........
There are over 2 million different Cap codes but only just over 250 thousand
Cap Code codewords transmitted.
So what you are experiencing is exactly what is supposed to happen with
kc2nda Messages: 40 Registered: December 2004 Location: New Paltz
If you want to use a serial device with the Arduino UNO, you have to make sure that you know that the serial lines RX/TX pins 0/1 respectively are tied to the USB. This means if you want to use a serial device on these pins, you must remove the RX pin in order to upload the sketch to the Arduino. If the pin is not removed, there will be an error message on uploading the sketch.
Once the sketch has been compiled and uploaded, you can put the RX pin back on. You cannot debug and use the serial port at the same time unless your device doesn't care that you are sending debug data to it.
If you want a good board to be able to debug and use a serial device at the same time use a Leonardo.
How to Use Arduino CH340G / CH341G Serial/USB Chip
What are the CH340G/CH341G chips?
Recent versions of cheap Chinese clones of Arduino boards have been coming with a different USB/Serial chip, which replaces the usual FTDI chip. Licensing costs of FTDI make it prohibitive to companies selling boards for as little as $3, so it is assumed this is the main reason.
Below you'll find links to drivers for Windows to make these work.
If you have one of these RS-232 to RS-485 converters (probably bought from E-BAY):
You will probably get a description like this:
* It is able to convert RS-232 signal to RS-485 balanced differential signal and extend the communihoneyion distance to 1.2km.
* It uses a particular pump to gain power from RS-232 signal (RTS, DTR, TXD) without initializing the RS-232 series interface.
* This interface converter does this without requiring any AC or DC power.
You will have problems with this converter from the arduino unless you read the spec sheet. Unfortunately the sellers will probably not give you the schematic or tell you how the circuit works.
I used this converter along with an arduino using the TX and RX TTL output to a MAX232 circuit, then this plugged directly into the RS-232 to RS-485 converter which in turn was connected to the power meter.
The response from the arduino was perfect. Not problems. But the power meter was not receiving the correct data.
The problem that the sellers don't tell you very clearly is what is needed to power the converter.
The trick here is to read this sentence a few times to understand it:
"It uses a particular pump to gain power from RS-232 signal (RTS, DTR, TXD) without initializing the RS-232 series interface."
So in order to get this RS-232 to RS-485 converter to work, you will need to hook the RS-232 serial port's DTR and RTS pins to the 5V Pin on the arduino (or another source if you have it), pin 5 of the serial port to Ground on Arduino, and the TX and RX from the Arduino to the corresponding pins 2 and 3 on the RS-232 port.
Pin 4 (DTR) - Jumper these two pins and hook to 5V from arduino
Pin 7 (RTS)
Once this is done, the RS-485 device will have enough power to send the correct data through.
*You could get around all of this by just purchasing a RS-485 plug in module for the arduino. It will save you a lot of time since these modules will convert the data for you without having to go to a TTL to RS-232 conversion, then to RS-485.
I have a rarely used Icom IC-220H that used to have very nice transmit audio.
Yesterday I transmitted and everyone said that it had low audio, and a little bit of a muffled sound. I pulled it from the car, and tested it on the bench. I get full power out, and all functions (as far as the usual menu items) work fine. It is set to the wide (W) setting, which is where I have always had it (it is really low, now, on the N setting).
There is now doubt that the audio is not what it used to be in amplitude or quality. My HT sounds much, much better, if that gives you any idea. Besides the loss of amplitude, there is a loss of bass, and perhaps a little muffle sound. It is hard to describe. I went ahead and drilled a bigger hole in the mic for the element to have a chance to get more from my voice, and that does not help at all, as I expected since it was working fine before.
A visual inspection inside the control head and the body of the rig showed nothing out of the ordinary.
I will say that the Jeep that this rig was in made a moderate amount of alternator whine. Maybe there are spikes on the 12 volts that zapped something?
RBoyette Messages: 2 Registered: September 2009 Location: Ft Myers, FL
I have several AT600 ADI radios from when I did search and rescue work. I pulled these radios out and they still work but I need new batteries. Where do I get them? How about a manual or anyone who knows how to program them? Any help is appreciated.RBoyette
Anyone repair cracked case's on a VX-170? [message #199]
Sat, 13 June 2009 17:54
Beltgunner Messages: 1 Registered: June 2009 Location: S.E. Ohio
I recently discovered my VX-170 has a crack running from the Antenna mount to the Battery compartment.I use this Radio doing relief work in hurricane zones so the waterproof feature is kinda important.Im not sure how much it would cost to get repaired considering I can get another Brand new Radio for $100 bucks on ebay so I'm not sure its worth messing with..Anyone have any Idea's?