Troubleshooting/Setup APRX on OpenWRT

Here are some troubleshooting steps I used when I was building my first iGate into a WRT54GL router.

See my original build:
http://ki6psp.blogspot.com/2009/12/wrt54gl-aprs-rxonly-igate-wopenwrt-aprx.html

When I was troubleshooting, I found an app that was a virtual console port, that allowed me to see a comm port from the CLI. I used "minicom" and it was really helpful in troubleshooting my data connection to the TT4. You will have to install the package, which is available through the packages on the web interface.

From the CLI, issue: Minicom -s Set it like the screenshot.

Then exit, and it will automatically open your serial port. If you are getting data, you should see a stream when the TT4 decodes packets (if your RXAMP is not set properly, you could also reboot the TT4, and you should get some text when it is booting.) If you don't get anything, verify the baud speeds (I found it easier to change the speed of the TT4, than the speed of the serial port, because the unit (OpenWRT/Router) outputs data during boot up. After booting is complete, the port is made available to use but with 9600 baud. If you have the TT4 set at the wrong baud, you may still see stuff, but it will be all garbage on the terminal. If all of the hardware is good, you should see something like this screenshot, mostly readable data.)

If you still have problems, try the folling until you have better results:
Verify you have a ground between all of the devices (floating grounds will screw up data)
Try flipping the data lines.
Are you converting the RS232 into TTL 3.3v for the WRT54G router?

Good luck
KI6PSP

New iGate Buildout

	After seeing no operational iGate in the Victorville, California area, I decided to build another iGate for deployment. I had an extra WRT54GL, and I acquired two Motorola Keynote receiver boards from a friend nearby. He pretuned them to the 144.390 MHz APRS Frequency for me to use for this iGate. After a lot of building and troubleshooting, this was the end result. An operational iGate without external peripherals, besides the antenna.
	I salvaged a window clip antenna and attatched the RF Connector onto the case, making this a clean looking iGate. Whats inside can be a mess, but it has to look good on the outside, and function. My previous version, I mounted an audio input jack to the case, and tied in a cheap scanner. This version will not have an external reciever, instead it is all inside the router case.
	Here is the rat nest of wire and parts. The Keynote reciever board was double stick taped to the RF case for the WiFi. The TinyTrak4 was left in its case, because of the proximity to the motherboard, and the power supply for the pager board sandwhiched in between. First I configured the TT4 with the Callsign, RXAMP, AMODE, and ABAUD. Callsign: KJ6HVB RXAMP: 9 AMODE: KISS ABAUD: 9600
	Here is the power supply I built for the pager board. LM317T Regulator and Schematic http://www.national.com/mpf/LM/LM317.html#Overview
	Keynote Pager Reciever Board. Pin 1 - 1.3 VDC Pin 2 - GND Pin 4 - Audio Out Pin 8 - Battery Saver (Jumper to power with 10k resister to enable receiver)
	This is a view of the bottom of the pager board, to show where to solder on the connector for the external antenna.
	This is the RS232 to TTL 3.3v converter. I had to modify it, so it wouldn't mess up the TT4. I cut the tracer between pins 7 & 8 of the Serial connector, and also cut the tracer going to pin 6. Pinouts (Components on top) Pin 1: Transmit TTL Pin 2: Receive TTL Pin 3: GND Pin 4: 3.3-5v Serial to 3.3v TTL converter (A232DBH3v): http://www.compsys1.com/workbench/On_top_of_the_Bench/Max233_Adapter/max233_adapter.html
	JP2: Pin  1: 3.3V          Pin  2: 3.3V Pin  3: Tx (ttyS1)  Pin  4: Tx (ttyS0) Pin  5: Rx (ttyS1)  Pin  6: Rx (ttyS0) Pin  7: NC            Pin  8: NC Pin  9: GND         Pin 10: GND

The end result, an operational RX Only iGate for an area that needs it, that isn't messy.
--
KI6PSP (Ed)

TinyTrak4D Project

I wanted to post my results of my TinyTrak4D project to the Amateur Radio Community, in hopes that someone might get an idea from me, or this would help somebody on their project.

	This is my TinyTrak4D Project box, I will have to work backwards on the construction. Because moding the case is pretty messy, and makes a lot on imperfections that look bad, I wanted to cover it all up while labeling stuff. I used a 8 1/2 x 11 white label paper from Staples, as Walmart didn't have any sticker material that would have worked. Felt cloth and glue wasn't an option. After labeling everything, I covered the label with a wide scotch tape to protect it. I got the light from the TinyTrak4 board to show through the case. I added a battery pack onboard for internal power, the ability to turn off the LCD backlight, Backlight Adjustment, GPS Power, and switchable config option. For the left side, I made all the connection points to simplify the interface and not make it as cluttered when using it. I made PortA available for interfacing (Currently used for GPS), the Radio port, a RX Line In so I can use my box for monitoring APRS only, A switch so I can change the JP8 option without opening the case, and something interesting, I added a USB interface as well as the PS/2 so I can use any keyboard. I had to dissect a USB to PS/2 adapter to understand what I had to duplicate, as the adapters are not just wiring.
Ok, inside you can see my internal wiring, its a little messy, but I did the best I could with what I had. I primarily used a small ribbon cable for the Radio and the Port A interface, because it isn't as bulky and I can bend it without causing problems. I used the space I created with spacers on the screen module to route a few wires. I wanted the screen to be near flush with the case. I tapped the corner holes of the screen board and used small screws to mount it to the case. You can see the battery pack I used, a plastic shell holding 8 Hybrid NiMh AA batteries. The Internal Power switch simply cuts off the power from the radio port pin 7, and connects to the battery pack. I had a bare ware problem with my construction that resulted in the batteries being charged in a very uncontrolled manner, destroying them, so I added a 1N4005 diode to each sided of the switch to control the direction of current. I later found my short, but left the diode to protect the batteries. The TinyTrak4 board is a V7.1, which is the surface mount design. I used this so I wouldn't have as much trouble with the display interface, and was happy that Byon trimmed the fat on this board, making it smaller. I had to vertically mount the board in the case so I could still have room for the battery, but that caused a problem with seeing the LED lights. I solved that later. For the keyboard interface, I found a neat PS/2 splitter cable, and after researching it, the standard PS/2 interface has 2 unused pins, and some manufacturers used the other pins so you can have a keyboard and mouse on one port via a splitter, pretty handy on laptops before USB. I trimmed some of the plastic of the keyboard connector so I could make it look good on the case. I cut off the mouse connector to convert it to the USB interface, and added 2 jumpers on the PS/2 - Screen board, pin 1-2 & 5-6, so I could bring the data from the mouse side of the splitter to the keyboard side. I took apart a USB to PS/2 Adapter and discovered why my first attempt at a USB interface failed. The adapter has 2 4.7k resisters going from 5v to both the data in and data out pins, the keyboard would not start without these.
Note from Firmware Manual: BNKMODE [ 0 | 1 ] Sets how the desired bank is selected at runtime. 0 means no bank switching, and only use BANK 0. 1 means to consider JP1, where open means use BANK 0 and closed or grounded means to use BANK 1.	Now for the LCD backlight control. It is a little hard to see, but the first thing I had to do was cut the power to the LCD Backlight LED. I cut it between the PS/2 Connector and the pin connector. There is a tracer that goes to pin 15 and I just scrapped it with an Exacto knife. Now because the switch and display are both mounted to the case, I took power from the Pin 2 on the display, right before it goes into C4. Then I ran that power into a 1K Potentiometer so I can adjust the brightness. I discovered that with the screen running at full brightness, unmodified from the manufacture, the regulator on the TinyTrak4 gets pretty hot. When I was testing this out overnight, I still had the bare wire short to the battery pack, but the temp inside the case reached about 140, a little to hot for my comfort. For the LED on the TinyTrak4 board, I took a small piece of plexiglass, and I made a 45 degree angle on one end, and used a silver colored Sharpie to help direct the light where I wanted. A rather lowtech approach but it works. No this wasn't my original idea, Richard at the local True Value gave me the idea, that's the reason I shop there instead of Home Depot. The weird dots you see is the mounting tape I used to mount the board vertically to the case. you can also see the wiring interface for the GPS Power switch. Its blurry, but the lower right is the wiring to the Config switch. When you set "BNKMODE 1", the unit will change from one bank to the other depending on if JP1 is shorted or not. See note from firmware.

Overall, I am pretty happy with the design. After using it for a while, I broke off the radio connector from the case, so I had to add the screws to hold them onto the case. During construction, it was fun trying to align the ports to the holes on the case, before the Crazy Glue set. Then scrap the glue mess from the port. I plan on adding a GPS module to it and attach it to Port B, so I can use Port A as a KISS interface or whatever, while maintaining GPS ability, that is the primary reason for the GPS Power Switch. I wanted to be able to turn off the GPS, when I don't want to beacon my location, but still monitor traffic.

The only thing I wish about this setup is out of my control. I can't use the calibrate function on this stand-alone setup, I have to play with the RXAMP settings if I swap radios. I have made a few suggestions for the way some of the data is parsed to Byon, like objects sent from a digi. I also suggested that he adds a menu so you can see a few objects relative to your location, and remember them like the Messages menu.

--

KI6PSP (Ed)

WRT54GL APRS RxOnly iGate w/OpenWRT & APRX

I wanted to build myself an iGate should the other one in town go offline. I began by purchasing a WRT54GL from Fry's and I re-flashed it with a Kamikaze version of OpenWRT. I bought a TinyTrak4 and flashed it with just the KISS TNC Firmware. The TinyTrak4 fit nicely into the case, with the small fan on the top, and the TTL Converter on the serial side of the TT4. The version I had was an older version, and I kept it in the case so it wouldn't get shorted out on the router board, it takes up more space, but I don't have to worry about it. I installed the small fan because I have discovered how much heat these can generate, especially if the modem is stacked with it. I couldn't do an easy plug on the top of the board to the header pins because of the TT4 case, so I had to solder to the bottom of the board to the contact points, that way I could enclose the whole setup inside the original case. Once I planed and installed the cables the way I wanted, I was able to get the whole package closed, and still be able to see the TT4 lights. I ran a small cable to the back of the case, so I could use a simple audio jumper into the cheapo scanner I was going to use as the receiver. I just used a Realistic Handheld scanner that only has 10 memories. It's perfect for APRS, because we only need max 2 channels. 144.390 MHz and the alternate 144.990 MHz.

I installed OpenWRT and During my research, I discovered X-WRT. It is a replacement web interface that allows you do just about anything you need to via the web. SSH console no longer needed once X-WRT is installed. I wanted to use APRS4r, but when I attempted to get that installed, I quickly ran out of memory, because Ruby (a dependency) is rather large. I don't know how to build my own OpenWRT image, so I started digging around and found APRX, it was in the package listings for the OpenWRT. I really didn't have to learn that much linux, because X-WRT has a file editor that allowed me to modify the files I needed without using the command line. I did have to use the command line to install the X-WRT interface though.

The version of APRX on the packages for OpenWRT was version 0.99. I configured that up, and got it to connect to the APRSIS, and start gating traffic. I did later run into a problem because I didn't have a filter setup in the configs. When you attempt 2-way communication via APRS, you must have a filter on the RX-Only iGates or the APRSIS will think it can send traffic back through your iGate, using the reverse path. APRS-IS filters are a way of telling the server you are connecting to, what you want from it. If you tell it you only want position packets, then the 2-way message traffic will find another way back to that originating station, even though you gated it.

APRS-IS Filters:

http://aprs-is.net/javAPRSFilter.aspx

The following are examples of the filters. The aprx.conf file shows the filter command like this:

aprsis-filter "m/100 t/p"

However, I noticed that it always ignored it, until I added a few spaces into the line like this:
aprsis-filter            "m/100 t/p"

Verify that the server accepted your filter by connecting to it via http://server:14501 and look for your iGate callsign, the filter will be on the "SA Setting" column.

***Replace "server" with the name of the server you are connecting to. IE: socal.aprs2.net
***If you use the default "rotate.aprs.net", you will have to look up which server you are connected to. It may require a Google search, as some servers are named differently. Use http://aprs.fi to find out which server you are talking to (IE: APRS via TCPIP*,qAC,T2SOCAL), then google it. IE: T2SOCAL is actually socal.aprs2.net, so you would use http://socal.aprs2.net:14501/

APRX 0.99 version configs:
aprsis-server    socal.aprs2.net    14580
aprsis-server    southwest.aprs2.net    14580
aprsis-server    aprsca.net    14580
aprsis-filter            "m/100 t/p"
radio serial   /dev/tts/1  9600 8n1    KISS  callsign KI6PSP-10
netbeacon for KI6PSP-10 symbol "R&" lat "3536.84N" lon "11741.06W"
comment "PHG0130/WRT54GL w/APRX-iGate Rx Only"
netbeacon ">TinyTrak4(KISSTNC)-WRT54GL iGate"
netbeacon ">SysOp:KI6PSP@GMAIL.COM"

Example Configs that I changed from default on APRX 2.00 and above:
mycall KI6PSP-10
server    socal.aprs2.net    14580
server    southwest.aprs2.net    14580
server    aprsca.net    14580
filter "m/1" #Had problems with it not accepting multiple filters, Gate all RX, reject APRSIS to RF beyond 1km of location.
serial-device /dev/tts/1 9600 8n1 KISS
callsign $mycall # callsign defaults to $mycall
#tx-ok false # transmitter enable defaults to false
initstring "\xC0\xC0\xFF\xC0\r\nMO 0\rKISS $01\r"
beaconmode aprsis
beacon symbol "R&" lat "3536.84N" lon "11741.06W" \
comment "PHG0130/WRT54GL w/APRX 2.00-iGate Rx Only"
beaconmode aprsis
beacon raw ">TinyTrak4-WRT54GL iGate"
beaconmode aprsis
beacon raw ">SysOp:KI6PSP@GMAIL.COM"
beaconmode aprsis
beacon raw ">http://KI6PSP.BLOGSPOT.COM"

TinyTrak4 Website:
http://www.byonics.com/tinytrak4/

Serial to 3.3v TTL converter:
http://www.compsys1.com/workbench/On_top_of_the_Bench/Max233_Adapter/max233_adapter.html

WRT54 Setup Ref:
http://www.dimebank.com/cak/k6dbg/k6dbg_igate.html
http://jdc.parodius.com/wrt54g/serial.html

APRX Ref:
http://ham.zmailer.org/oh2mqk/aprx/

X-WRT Install Info:
http://wiki.x-wrt.org/index.php/Kamikaze_Installation