TinyTrak Message Board
This message board is devoted to TinyTrak, to ask questions, leave comments, and see how others are using TinyTrak. Byonics responses are shown in green. You can also send questions eMail to byon@byonics.com
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From: ian hamilton-douglas (G6VND) on Wed Jun 14 08:25:41 2000
has anybody used a kenwood TH-D7E hand held tranceiver to receive signals from a tiny trak,iam thinking of buying such a tranceiver,and would like to know how they got on. thanks and 73's
From: Joel Black (K2SAT) on Sat Jun 10 18:31:29 2000
I *cannot* make the TinyTrak work. I cannot decode packets. I have tried adjusting the deviation all the way down until you can barely hear the data. I have used all calibration values. I getting disgusted!
You do not want the deviation too low. It should be just below maximum discernable by ear. If you are using a Kantronics TNC to listen, try CD internal instead of CD software.
From: Byon Garrabrant (N6BG) on Sat Jun 10 11:14:54 2000
Back Order Update: I just filled and mailed all orders placed or post-dated before June 1. I hope to have all remaining orders shipped within about 2 weeks. Thanks for your patience.
From: Bertus Wijck. () on Fri Jun 9 11:24:45 2000
Hello to you all, I search for a simple DOS/WINDOWS NMEA LOGFILE PLAYER true TINYTRAK. So we having a small TT simulator. Is there anyone who is willing to give me a hand or two ?
I've been using a serial program called TTermPro. You can have it send a text file, with a delay between each line. This may help.
From: Jim Korenz (N8PXW) on Fri Jun 9 06:51:02 2000
Great Gismo !! Got mine talking to a Motorola PVT-6 and a Magellan Meridan GPS. I have the same problem as Peter PE7PH. My unit talks to an MFJ TNC-2, but my Kenwood D7-A ignors the packets. Your previous advice was to adjust the calibration value. I am using a 10 MHz crystal. Do I still need to "fudge" the value ? Or is this a problem with the Kenwood's TNC ? Thanks, for a great little project. I could write a simple DOS setup program, for those who want to run a simpler system. 73's JimK
If you are having decoding problems, especially if it works on some TNC's and not others, you should adjust the calibration value.
From: Hans () on Thu Jun 8 14:51:08 2000
GREAT TIP James ! Specialy for city area's.
From: James Vincent (G1PVZ) on Thu Jun 8 10:45:28 2000
An update on the Magellan NAV5000 and TinyTrak interfacing. A simpler solution instead of adding a MAX232 is to connect a 12k Ohm (approx) across the output of the Magellan data lead (pin 2 and pin 9). Then connect pin 2 to the Tinytrak input and pin 9 to the TinyTrak 0 V line. The GPS will then work with the TinyTrak. It is because Magellan provide a current source rather than a voltage source for the NMEA output. It complies with the earlier issues of the NMEA standard. A suggestion - without bloating the design too much would it be possible to increase the beaconing rate as the GPS position changes more rapidly. i.e position reports are more frequent with increasing velocity ? Regards, James
I do have "Smart Beaconing" on the ToDo list. Thanks for the Magellan suggestion!
From: Markus Fackler (DL1GFM) on Thu Jun 8 10:45:01 2000
Does TinyTrak work with a 0-5V input from a gps ? I have to send +-12V into the PIC to decode my RMC signal... Is this normal ?
If the GPS sends 0-5Vs, and it is readable by a PC, it should be readable by TinyTrak. If it send -/+ 12 volts, it should also work. Both are normal.
From: Mike Connors (KI7AB) on Tue Jun 6 20:15:54 2000
There is a picture of my completed TinyTrak and enclosure at the NWAPRS (Northwest APRS Website). http://www.nwaprs.org/tinytrak.htm 73, Mike
Thanks! any others with pictures out there?
From: Joel Black (K2SAT) on Tue Jun 6 11:20:58 2000
Put mine together in an evening. Tested next day and couldn't get 5V out of the regulator. This morning, I looked at it again and noticed some solder had shorted two traces. Didn't see that before. Anyway, got it configured, now to interface it to my FT-8100 and in an enclosure. Anyone have any good enclosure ideas? 73 de Joel, K2SAT
From: terry@wireless.force9.co.uk (G4CDY) on Mon Jun 5 14:16:46 2000
Super design Byron, save me a lot of effort. I am going on a charity walk in two weeks involving walking up the three highest mountains in the UK. Intend to take a TT with homebrew 20w radio and GPS120. What I need is a simple way of changing the beacon text as I walk. I will take a HP95 palm top which has a terminal emulator or I could write a simple DOS program (only a 80C86). Have you published the commands to program the beacon text? 73 de Terry
Thanks. I have not published the configuration protocol, but will be happy to share it with those who need it.
From: Rich Morrall (G8ZHA) on Mon Jun 5 03:41:52 2000
Can the DCD input be used digitally from a radio that has a squelch output - if so what polarity?
I think that would work. Just remove R9 & C2, and pin 10 should be grounded during carrier, and floating or 5V when quiet.
From: Ray Rischpater (KF6GPE) on Sat Jun 3 23:21:55 2000
Nice kit! Just finished up my first TinyTrak for my father, WD6DVG, and his RV. Stuffed it into a little Radio Shack box, with the lights on the top and jacks along the sides. Works great; plan on getting a couple more and buidling them up as gifts for other ham friends. Good luck & 73 de KF6GPE
From: Gerhar Paul (DF6SW) on Sat Jun 3 13:14:56 2000
If I buy a Tiny Track Kit, do I still need a PIC16F84 programmer?
No, the kit comes with a programmed chip.
From: Mike Pischel (kb0tiy) on Sat Jun 3 07:44:38 2000
OK, I've gotten biten by the Tiny Trak bug! Now It's my turn to build several of these. First of all, Is everyone happy with the performance? This project is creating alot of excitement around here! Best of 73's to everyone! Mike
From: Chris (N1UOC) on Fri Jun 2 23:01:55 2000
Is the a DOS Config Program? Instead of Windows. I use an old 286 laptop.
Not currently. Would anyone like to write one, I'll provide the Windows source.
From: Jeff (kc8ffv) on Wed May 31 12:23:13 2000
The unit is alive, but I am having a problem with the transmit locking up on the radio. Also I am not sure if the unit is actually transmitting the data out. but this could be caused from the tx lock up?
Try the capacitor on the PTT transistor, and mentioned earlier.
From: Jim Hopper (K5IWK) on Wed May 31 03:26:09 2000
With regard to the need for power to program the Tiny Trak. Could I get the 12v from the computer on the serial port plug?
I haven't tried it, and don't recommend it, but it might be possible.
From: Jim Hopper (K5IWK) on Tue May 30 18:44:34 2000
I just finished the Tiny Trak and have a Rand McNally GPS to hook to it. It transmits the Beacon ok but sends "Error" because the GPS isn't attached. 1. How do I get voltage to the GPS? Which pins do I use? 2. Do I need a "Null Adapter" to hook it up? I already have the male to male.
I removed both connectors on my RM GPS. Connect 5 or 12 volts to the red wire, ground to the shield, and the white wire to the TinyTrak. If you do not remove the connectors, you will need a NULL modem/gender changer if you use the supplied female DB-9 on TinyTrak.
From: Byon Garrabrant (N6BG) on Mon May 29 23:40:30 2000
To send a position after unkeying on voice, wire the mic audio and ground directly to the radio, and wire the PTT through a 1N4148 diode as shown. The mic end should connect to TinyTrak PTT IN, and the radio end to TinyTrak PTT OUT. I will be adding this information to the manual. I've noticed that with the current version of the firmware (1.0), there is a short unkeyed pause between releasing PTT, and TinyTrak re pressing PTT and sending the data. I hope to have a new firmware version to fix this soon, and will need some volunteers with PIC programming ability to help beta test it. Thanks.
From: Curt Mills (WE7U) on Mon May 29 18:24:43 2000
When running the Win32 program, the TinyTrak DOES need to have power applied.
From: Lou Roux (W6UR) on Mon May 29 16:02:52 2000
Just completed my TinyTrack. When I run TinyTrackConfig.EXE (and choose the proper COM port, etc.) "check version" says TinyTrack not found. Does the TinyTrack have to have power applied to load the configuration file?
Yes, it does require power during configuration.
From: Curt Mills (WE7U) on Mon May 29 14:39:16 2000
Paolo: Put in the 0.1uF cap between the transistor and ground, as someone mentioned in previous messages. It really helps with the RF lockup problem.
From: Curt Mills (WE7U) on Mon May 29 14:38:28 2000
Trimble SV6: Yes, if you set it to NMEA mode (instead of TAIP or TSIP), then it only puts out $GPGGA and $GPVTG sentences. I have two of those units myself, and hope to either modify the TinyTrak S/W to do $GPGGA, or else put in another 8-pin PIC chip to do the translation for me. On the TinyTrak home page though it mentions GGA support on the TODO list.
From: Brian (VK4BBS) on Mon May 29 04:31:38 2000
To All Hi Folks I have a Trimble SVEE SIX GPS but am unable to get it to send RMC messages. I do have both the GPSSK and TSIPCHAT software but still unable to get those RMC messages. Wonder if anyone else has experienced the same problem. Regards Brian VK4BBS
The current version only decodes RMC, but GGA should be coming in the future. I also belive the SVee Six uses TTL serial, instead of RS232, which should require the need for an inverter/transistor.
From: Paolo ANGELA (IK1HSO) on Mon May 29 04:31:10 2000
Great TinyTrak!. It's OK at the first step. .... but with the car I had a few problems with RF. Right for the use of SW2: two messages it will be right. Sorry for my english. 73 de Paul.
From: Hans () on Sun May 28 14:41:10 2000
TO BYON: We cant get the MIC-E function to work.When possible to update the diagram or some feetback getting stuck here, please.
Added above.
From: ian hamilton-douglas (G6VND) on Sun May 28 11:50:26 2000
TO ALL,does the tiny-trak have a 9 pin femail socket on it or a male socket?also i have lots of 16f84-04/p ,pics in circuit boards from work.can i reprogram them,i do have a simple pic programmer but i dont know how to erase the original program on the chip many thanks as iam considering the peekpack project
It has a female socket, but it can be left off or replaced with a male. TinyTrak must be clocked at 10 Mhz, and the -04 chips are not rated for that speed. However, I have heard reports that it does work.
From: Simard Normand (ve2lhs) on Sun May 28 09:07:32 2000
I cannot communicate with my TinyTrak an a COM 1 Please help m. After a burn a 16F84 with the firmware TinyTrak, the message indicate the COM 1 is not disponible. Welcome VE2LHS and sorry for my English
Double check your solder joints. Perhaps try a different computer. Make sure you have no other software trying to use COM1 at the same time.
From: Mike Connors (KI7AB) on Sat May 27 20:29:54 2000
I finished my TinyTrak last weekend. I put it inside one of the Radio Shack boxes. I mounted a coaxial power jack, a small slide switch and 9 pin DIN connector on the outside of the box for easy access to programming and transmission rate changes and convenient power hook-up. It worked out great! Instead of using the metal cover that came with the Radio Shack box I simply cut out a cover from a clear plastic bakery container so that the LEDs are visible. Great job Byon!
Thanks. If you or other users would like to show pictures of your TinyTrak's, I'd be happy to link to them.
From: Bob Morehouse (KB7ADO) on Sat May 27 19:44:50 2000
Byon, just wondering if you have any plans to attend the ARRL Northwest Div. Convention in Seaside, OR, the first weekend in June with some of your products. There will some people from the NWAPRS group with a demo table and at least one APRS seminar, so it would be another opportunity to show off your TinyTrak. APRS activity is picking up in this part of the country, with numerous inquiries on our sig about the TT. I'll probably be putting in an order for one in the near future.
No, I wasn't planning to. Sorry.
From: Bill Vodall (WA7NWP) on Fri May 26 21:36:24 2000
It lives. Even survived a shorting of the power leads. Now for a box. The TinyTrak board has mounting holes. Any chance it's designed to fit one of the stock Radio Shack boxes?
It wasn't designed to, but a few users have used them.
From: Rick Bandla (VE3CVG) on Fri May 26 07:11:25 2000
Sorry. Found the info on Ludipipo & Pix on your PeekPack page. For the slower folks (like me) you might wanna put a link to those pgms from your TinyTrak page. Great site by the way. 73. Rick
From: Rick Bandla (VE3CVG) on Fri May 26 05:45:45 2000
Byon, You used to have some sample programmers in a file at http://www.byonics.com/pic/picprogimg.zip It's not there anymore, have you still got it around or do you know of anyone else who has a page dedicated to this info? 73. Rick (VE3CVG)
From: Byon Garrabrant (N6BG) on Thu May 25 22:53:57 2000
TinyTrak BackOrder Update: I received parts to fill many orders today, but it was still not enough to fill all of them. I currently have filled all PayPal, check, and Dayton orders, and all CCSLIDE orders placed before May 12. I hope to fill all remaining orders in about 10 days. Sorry for the delay, and thanks for your understanding.
From: Curt Mills (WE7U) on Thu May 25 12:10:02 2000
$GPGGA: No, not currently supported. It parses the $GPRMC sentence right now. Byon mentions on his main page that he might add that (I want it too). A friend of mine was working on it a bit also. It's not difficult, just a time issue. Regarding the vhf-link, yes, a TinyTrak will work with a transmitter to send your position out, but you'll need something other than a TinyTrak to receive the signal, like perhaps a Kantronics KPC-3 or KPC-3+ TNC, or actually ANY packet radio TNC should receive the stuff just fine. We use 1200 baud AFSK for this APRS stuff. A TinyTrak is basically a transmit-only TNC. No receive capability.
From: Markus Fackler (DL1GFM) on Wed May 24 21:38:55 2000
Hi to all. I want to use TinyTrak with a PGS-Board that sends out the GPGGA data. Will this GPS work with TinyTrak or not ? 73 de DL1GFM
Not currently, but the feature is being added.
From: Bo Andersen (OZ1CPP) on Wed May 24 19:32:16 2000
Hey Guys !! I´m new to this stuff , but is TinyTrak the unit I need to be able to transfer the posiition from my GPS to my home computer via a vhf-link ( I suppose that I need two TinyTraks ) ???
Yes, but you do not need two TinyTraks, just the one in the field. At home you should have a TNC / radio / computer. Or, if you live in an area with an IGATE, all you need at home is a computer connected to the internet. Take a look at www.findu.com
From: ian hamilton-douglas (G6VND) on Tue May 23 08:07:48 2000
does anyone have an estimation of how long it will take to get comformation of my tiny-trak order thanks and 73's
I normally ship within a two days of receiving an order. If you have any questions about your order, feel free to eMail me at byon@byonics.com
From: Hans () on Tue May 23 02:15:31 2000
ALL: Other thing i found out. When using calibration mode, lower value is 36 and no lower value is possible, upper will go up to over 200. Why is this ? ( i like find upper/lower level where TNC is decoding TT data )
These are the limits of the calibration algorithm.
From: Hans () on Tue May 23 02:12:39 2000
ALL: How das the MIC-E function is working in TT ? I connect mic PTT wire to go in DIODE and leave other connections, like normal using TINY on this radio. But Radio is not key up for TX. Radio is Kenwood, PTT go to ground. How come ?
See the schematic above for more information.
From: Peter (PE7PH) on Mon May 22 01:13:51 2000
I have a problem reading the tt signal on kenwood equipement D& and D700, only after the signal is repeated by a tnc-pc station the signal is accepted by kenwood??? any idea 73 peter
It sounds like the timing may be off, and can be decoded by some TNCs, but not your Kenwoods. Try tweaking the calibrate value around.
From: Peter (PE7PH) on Mon May 22 01:11:40 2000
Is it possible to use tt in combination with a Davis weathermonitor2 as a stand-alone WStation???
Currently, TinyTrak only reads a GPS, but I hope to add a weather version soon.
From: Curt Mills (WE7U) on Sun May 21 18:03:33 2000
Wire your microphone PTT into the diode that goes into the PIC chip. Wire the TinyTrak outputs to the radio. When you push the PTT button, the TinyTrak keys up your radio for you, and when you let go, the TinyTrak does a position blip and then unkeys the radio. You'll have to break the PTT wire between the MIC and the radio to do this. I haven't tried it yet, but I asked Byon earlier and he mentioned that it should work.
From: Vincent Endter (KF6WAV) on Sun May 21 11:30:05 2000
How do I wire my Tiny Trak so it transmits after keying the mic instead of a given number of seconds?
See the schematic above for more information.
From: jim scott (n8orj) on Sat May 20 10:17:48 2000
1) what is the size of the finished board? 2) will the tiny trak accept the inverted ttl data from your gst-2 chip via the marvin gps?
The PCB is 2 x 1.6 in, a little longer with the DB9 connected. And yes, you can use the inverted TTL output of the GST-2.
From: ian hamilton-douglas (G6VND) on Fri May 19 08:30:25 2000
thanks for the reply mark,the gps was only going to transmit when the free flight plane has ran out of fuel and landed. i would like to build a more modern version of the wood and douglas 2 meter transmitter i built about 18 years ago any sugestions ?
From: Lee Devlin (K0LEE) on Fri May 19 05:35:59 2000
I just wanted to follow up to an earlier problem I reported. I was unable to get the PC to communicate with the TinyTrak. It turned out that a trace smaller than a human hair was shorting pins 3 and 1 on the PIC. I don't know if this was a result of a scratch on the board artwork, or a thin wire getting plated on to the board. It was nearly invisible except under a magnifying glass. I scraped it away and everything began working.
Thanks for the update.
From: Mark Phillips (G7LTT) on Thu May 18 11:16:35 2000
Ian; I don't suggest you use APRS on 2mtrs from your plane as that would be contrary to your licence conditions. I would do it using one of those new 4440Mhz handhelds which run off a few AAA cells. As I understand it they are licence free. How are you gonna deal with the weight of a gps, TinyTrak, radio and RC control kit in your plane though?
From: Mark Phillips (G7LTT) on Thu May 18 11:10:59 2000
What about CW ident for us non US stations?
Is this for legal reasons? Is the callsign in packet not sufficient?
From: ian hamilton-douglas (G6VND) on Wed May 17 11:38:44 2000
just ordered a tinytrak to locate my model aircraft any suggestions?
From: Hans () on Wed May 17 10:15:04 2000
Hello to you all, We in PA0 country using 10 mhz. Xtals only.Das anyone want to share there upper and lower calibration values, please.
From: Curt Mills (WE7U) on Wed May 17 08:43:12 2000
Daqarta works like a champ! I'm very impressed with it, particularly 'cuz it runs on DOS and is cheap(er) shareware. I checked the tones on all three TinyTrak's last night and they're all up to snuff now.
From: Vince Endter (KF6WAV) on Tue May 16 19:04:43 2000
It works! I finished my Tiny Trak today and tested it with a Rand McNally GPS. I am using 4 NiMh batteries to power both the Tiny Trak and the GPS. Current draw is about 160 mA. That should give me about 8 hours of operations, which is plenty for my purpose (hang gliding).
From: Curt Mills (WE7U) on Tue May 16 08:57:20 2000
Sorry, that was www.daqarta.com. Shareware spectrum analyzer software for DOS that can use soundcards. Looks like it's worth a shot anyway. Anyone have a simple cheap method for setting deviation?
From: Curt Mills (WE7U) on Tue May 16 08:54:28 2000
Regarding calibrate & 10 Mhz Crystal: I had to drop the calibrate value down a bit from the default 63. I think I used 49 on one. I transmit to another TNC and adjust the cal value either direction until it DOESN'T work, then set it for the middle. I'm going to check out www.deqarta.com to see if I can do an FFT to get things set more accurately.
From: Hans () on Tue May 16 06:44:20 2000
About 'start the car' problem. We in NL found same problem. Use small caps but not salve this irri problem, yet !
From: Guy Beaumont (G7BWP) on Mon May 15 23:11:33 2000
Has anyone else had problems with the timing parameters being corrupted if the TinyTrak is on when I start the car! Typically I set it to tx every 30secs. After the voltage has dropped due to starting the car it seems to become 1390 secs. Not quite so useful with 23mins between txing. I'll have to look at adding some caps to the 5v supply for the PIC.
I've been running TinyTrak in the car, and have not seen this problem. Others?
From: Carl Davies (M1ELR) on Mon May 15 10:39:10 2000
Hello all, Can any one tell me how much I would have to adjust the calibrate value is it +/- 1 or 10 or 20, I have used a 10MHz crstal instaed of resonator..
I've heard reports that settings in the 50 range well. Try a few differnt values.
From: Don McPherson (KK7MJ) on Wed May 10 13:29:50 2000
Does anyone have experience with hooking TinyTrak to a Kenwood G71 HT? I cannot get the unit to key the radio no matter how I try. Any help or pointers would be appreciated. I am using an MFJ TNC cable with it.
From: Lee Devlin (K0LEE) on Mon May 8 22:08:44 2000
Does anyone have any suggestions when the tinytrakconfig.exe program cannot find the tinytrak? The tinytrak powers on OK, flashes the grn/amber LEDs twice and the PTT once and will trigger the PTT every 90 seconds, but I cannot program it via the serial port. The serial port works fine with other devices. I am not using a laptop. Thanks, Lee, K0LEE
Double check for soldering problems. You can run a terminal program at 4800 N81, and send ESC V to test the serial link. The version should be sent back.
From: Curt Mills (WE7U) on Mon May 8 14:52:00 2000
1) I highly recommend the 0.1uF cap that Sylvain Mercier (VE2SIL) suggested: Tinytrak is not locking up with 50W transmitter next to it. 2) Calibration value is critical and must be adjusted for each TinyTrak. Find the highest/lowest calibration values that allow decoding on another TNC, then average the values. TinyTrak's #2 and #3 didn't work for me until I did that. 3) Anyone have a true-DCD squelch circuit yet?
Very good point. All users should adjust calibration if they have problems decoding TinyTrak transmissions.
From: Byon Garrabrant (N6BG) on Fri May 5 23:45:35 2000
I received more orders than expected, and ran out of parts. I just got more in today, and am filling all the back orders as I type this. Sorry for the delay.
From: Rory Dowler (VE3RRY) on Fri May 5 16:15:16 2000
I ordered a TinyTrak online through ccslide.com last week (April 25-26). I had hoped I would see a confirmation of my order by now.
I do not think CCSLIDE will send a confirmation when you place an order. However, when I ship the order, and charge the credit card, a confirmation it sent.
From: Carl Davies (M1ELR) on Fri May 5 12:40:25 2000
I have just built a Tinytrak and I can't praise it enough I now have a TNC free to use for other projects. Many thanks for such a good project.
From: Jon Wetterholm (KD6BPE) on Thu May 4 17:27:41 2000
Where can I get one of these that is already built? Jon
I am currently not supplying pre-built TinyTraks.
From: James Jefferson (KB0THN) on Wed May 3 06:17:09 2000
Hello everyone - I received my TinkTrak last night and had it built in about an hour. I'm going to give to a friend so he can get started in APRS, but I'd would like to put it in some sort of enclosure first. I've used NEMA 4 die-cast aluminum enclosures before and I would like to do something like that again, but I am looking for any case suggestions.
From: Curt Mills (WE7U) on Tue May 2 03:46:43 2000
My Mods: Leave off all LED's for lower power consumption -or- install only the GPS valid data detect LED -or- put GND of some LED's to another switch so they can be turned off. Added 5.1V zener and schottky diode from GND to CPU pins for both serial pins, 390 ohm resistor from serial out pin to connector. This protects the inputs (see spec sheet for IC). Changed pinout of connector to look like PC so that GPS's interface easier. A null modem adapter is then needed only to program the TinyTrak. Changed to 10 Mhz xtal and caps instead of resonator. Changed to LM2931? regulator instead of 78L05 (lower quiescent current/low dropout). Will try PTT fix listed below as that's happened to me. Anyone have a fix for using unsquelched audio with a TinyTrak? The backoff circuit doesn't seem to work with unsquelched audio. Am also thinking about putting the 2.2k resistor on a switch so I can change between HT and Mobile rigs easier. Made the radio connector a DIN-5 in a TAPR-2 pinout so all of my radio cables will work with each TinyTrak. Oh yea, I was also using a programmer that did not automatically program the EEPROM. This gave me startup problems (TinyTrak's didn't want to talk to the PC). Finally started programming the EEPROM's as a separate operation and each TinyTrak came up fine.
These are some great ideas, Thanks Curt!
From: Bob Weybrecht (N2QEW) on Sun Apr 30 19:04:44 2000
Regarding James Vincent's problem: It's possible that the 10 MHz clock is far enough off frequency to cause the software UART in the PIC to occasionally mis-interpret a character. Uploading the config to it may work because it's a short message, or because the uart in pc the is closer to the rate that the software uart is operating at - not necessarily more accurate, just closer. If you can capture NMEA strings into the pc from the GPS, try sending them back to the tinytrak a line at a time. Also, the GPS may be sending the messages too close together to allow the tinytrak to digest each message before the next gets to it. With no specific information about how they handle the cal value, and the clock, but general info about past experience regarding the PIC and serial comms. Those would be my guesses. I've not built one of these yet, but it looks interesting. Check the frequency of the clock, get it really close to 10 MHz - replace the resonator with a crystal with a 22 pf cap from each lead to ground if necessary, and set the cal value to the default. I made a suggestion previously that they add the ability to send a known frequency audio tone that could be measured so that the cal value can be accurately adjusted. Triggering it could be done via the programming program, or by an I/O pin. Seems to me that these guys have accomplished an amazing thing, now we get to suggest the bells and whistles.
From my experience, serial can deal with timing errors of up to about 5%. The accuracy of the ceramic resinator is much better than this.
From: Paul Jacques (WB6IWT) on Fri Apr 28 10:51:18 2000
How about modifying the firmware and configuration software so that a fixed posit can be entered, thus eliminating the need for a GPS at a fixed station?
This can be done somewhat by sending a NMEA string into TinyTrak with the position. As long as power remains, it will beacon that position. I will add a better solution to the wish list.
From: James A Vincent (G1PVZ) on Wed Apr 26 11:56:37 2000
Hello,I have finally constructed a TinyTrak. I had to use a crystal rather than ceramic resonator as I couldn't get a 10 MHz ceramic resonator easily in the UK ! Unfortunately I have a problem ! My TinyTrak can be programmed via the Win95 configuration program and my Standard handheld radio is keyed at the specified intervals. The carrier detect circuitry is not yet connected to the handheld's rx audio output. But by twiddling the pot you can illuminate the carrier detect LED and tx is inhibited and by moving the pot the other way (to simulate no rx audio) the LED goes out, then flashes once and the transmitter is re-enabled. I have tried connecting two different Magellan GPS to the TinyTrak but I don't get any response from the GPS data validity LED. It remains off ! I checked the the NMEA 0183 (4800 Baud) data from the first GPS (ProMark X) by connecting the GPS data lead direct to a pc serial port and monitoring it using HyperTerminal. On HyperTerminal I could see what looked like valid NMEA sentences. I also monitored the GPS NMEA input at the TinyTrak pin 3 with a scope and I could see approximately one second bursts of data. I then tried a NAV5000 GPS which allowed the selection 0f NMEA 180, 0183A, 0183B and 0183C again none of these selections resulted in any output from the GPS status LED. I monitored the received TinyTrak VHF transmission off air with a packet program and I got the following AX25 message- 18:18:52 G1PVZ-1>ER%OR!,APRS,WIDE,WIDE Port=1 :NŸàGPS >/(g1pvz@arrl.net) So I suppose most of the system is working- apart from the Tracker's positon ! I would be really most grateful if ayone could give me some advice on what I am doing wrong - I have doubled checked my wiring and stripboard lay-out. I have even built a single transistor inverting and non-inverting buffers (clamped to +5V) but using either buffer on the GPS serial output doesn't make the TinyTrak work ! I think it is significant that the TinyTrak will accept data from the pc (for configuration) but not from a GPS for positioning. Thanks for designing TinyTrak- I am frustrated at very nearly having your elegant circuit working ! Regards, James G1PVZ
It turns out that the Magellan NAV 5000 GPS RS-232 interface lead was not in fact RS-232 at all. Adding a MAX233 corrected the problem.
From: Sylvain Mercier (VE2SIL) on Tue Apr 25 10:56:46 2000
Tinytrak is a beautiful project! If you have a problem with Tinytrak:PTT LOCK ON STONG RF SIGNAL TX,put a .1mfd. 50v. capacitor directly on ptt transistor (Q1) BASE AND EMITTER 73 de Sylvain
Thanks for the great tip! I'll add it to the Hints section of the manual.
From: Johan Hansson (SM0TSC) on Tue Apr 25 01:23:06 2000
Byon! My tip regarding future enhancments. Add the possibility to change STATUS via switches!! Is it possible. The MIM have it thou it uses another PIC! /SM0TSC
It's on the wish list. Thanks!
From: Mike Robinett (KE4UVQ) on Mon Apr 24 18:39:15 2000
Im using the Rand McNally ($79.00 from their site) I just ordered a Tinytrack, Im wanting to build the smallest tracker I possibly can (arent we all?) Should be fun! Thanks Byon!
From: Vince Endter (KF6WAV) on Mon Apr 24 16:13:30 2000
What is the smallest and cheapest GPS that will work with the TinyTrak?
I don't know the smallest and cheapest, but as long as it sends $GPRMC at 4800 baud, it should work.
From: Alex (KG4ECV) on Mon Apr 24 10:54:36 2000
Hi there, I'm a newbie when it comes to trackers, so forgive my ignorance on the subject. I was wondering if SW2 be used to switch between messages...for instance between "In Service" and "Emergency!", or would that be of no use? 73, de Alex
It could, though I'm not sure how interested people would be in this. I will add it to the wish list. Thanks!
From: Bob Weybrecht (N2QEW) on Sun Apr 23 20:01:52 2000
A couple of suggestions... Switches: Allow changes in path via the switch (or switches) I realize EEPROM space in '84 is limited, but R or W or other characters that aren't commonly used in a path could function as Relay, Wide or other common paths. I suggest this because in traveling, I've found that there is still no real standarization in the path to the net. Calibration: I don't know how temperature stable a resonator is, but a trick I use in some of my designs with internal oscillator pics is to generate a known frequency tone on a pin, measure it, and alter the cal (osccal in my case) value up or down to make the tone be the correct frequency. You could trigger this with a serial command, or by an I/O pin. If you did 2200 Hz, you could accomodate the deviation setup request I saw in this forum with the same code, although a higher frequency oscillator calibration tone would be more accurate.
From: Jeff King (WB8WKA) on Sun Apr 23 17:46:41 2000
Larry: If you change the linear regulator to a switching regulator, you should be able to cut power consumption in half. Also, I haven't looked at the source yet, but you might be able to use the sleep command in the PIC to further reduce power consumption. As a example of how this could be done, is the serial port could come in on one of the port B's. So when the data is coming in, it wakes the PIC, then decodes the data. Then the PIC decides if anything needs to be done (like transmit) then if not, goes to sleep until the next GPS sentence comes in. If the only sentance being sent is the $GPRMC one, then you should be able to reduce power consumption another 33% or so. Then again, 6.6ma is not a whole lot, especially compared to the transmitter you'll be driving. So you can break your head trying to get the PIC down to under a 1ma, but that 1000ma transmitter kind of makes things moot. -Jeff
From: Larry Mcdavid (W6FUB) on Sun Apr 23 16:32:54 2000
What is the current drain with 12 vdc input? Was anything done to minimize this current drain? I'm thinking of an application requiring very small, battery-powered and free standing units.
TinyTrak, without LEDs, draws 6.6ma. Each LED with a 1K draws 3ma, so with an average of 2 on, the draw is 12.6ma. If you switch the LED resistors to 10K, they will only draw 0.4ma each, but will be dimmer. They can also be left off completely.
From: Tyson S. (n7zmr) on Sat Apr 22 20:29:18 2000
Hello! I am very new to this APRS stuff and am wondering if this unit will work as a tracker in conjuction with Delorme Tripmate GPS? I plan on using a small handheld radio to make a tracker and use a kantronics KPC-3 at home. Am I in the right mode of thinking?
Yes!, you are on the right track. TinyTrak should work fine with a Tripmate and an HT. BTW, it would NOT work with an Earthmate, unless you also used a GST-1.
From: Graham Le Good (G4GUN) on Sat Apr 22 14:36:15 2000
Got my Tinytrak v 1.0 going this pm. Hassle was building the PIC programmer! Quite a few UK stations are now starting to use these. Well done. It might help if in test mode a steady tone could be sent out to enable the TX deviation to be adjusted.
Good idea, I'll add that to the TODO list.
From: Dan Dicke (KE6NYT) on Thu Apr 20 23:05:27 2000
Great Board! The board and the direction have made this kit so easy even I did it in less than an hour and I have never built a kit before. It works very well. I have already got 10 orders for them from our BOD for Sulphur Mountain Repeater Association so that we can free up ten TNCs that we are using as trackers for ARES/RACES. Great job to Byon and the rest of the design team. 73 Dan Dicke KE6NYT Ventura County Deputy District Emergency Coordinator Ventura County ARES/RACES Digital Communications Coordinator
From: Nick Baas (VK4TMC) on Thu Apr 20 22:41:46 2000
What ia the purpose of switch 1 and ?? !73 de Nick
SW1 is used to switch between the primary and secondary report rates. If you hook it to your auto ignition, you can make it report every 5 minutes while driving, and every 30 minutes when the car is off. SW2 is not currently used. Any ideas?
From: Byon Garrabrant (N6BG) on Thu Apr 20 00:15:19 2000
Hi, and thanks for stopping by the TinyTrak message board. You can leave messages to me and others here regarding questions, problems, ideas, praise, or whatever. 73, Byon
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