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Dead / Bricked Tinytrak 4

 

Hi Group,

I got my hands on this bricked TT4.
The person who gave it to me said it was exhibiting erratic behavior (bad decoding, not transmitting). At some point he tried to upgrade the firmware, and ended up stuck with the TT4 in this state.


When powering up it does not even show the boot loader message on the connected terminal. Any ideas ?

--
___________________________________________________________
Geoffrey F4FXL / KC3FRA
My Tinytrak Stuff =>

 

Geoff,

When you send the "B" while trying to enter the bootloader, what does the terminal screen show? Continuous dots? Anything? It can be difficult to catch the bootloader when you do a reset by just cycling the power. A "hard reset" by shorting the TT4 chip RESET pin to ground briefly will give you a better chance of getting to the bootloader?and reloading the firmware. It is not terribly likely that an abortive attempt?at reloading the firmware bricked the bootloader beyond repair.?

73,

Allen AF6OF

On Sat, Dec 17, 2022 at 11:11 AM Geoffrey Merck <f4fxl@...> wrote:
Hi Group,

I got my hands on this bricked TT4.
The person who gave it to me said it was exhibiting erratic behavior (bad decoding, not transmitting). At some point he tried to upgrade the firmware, and ended up stuck with the TT4 in this state.


When powering up it does not even show the boot loader message on the connected terminal. Any ideas ?

--
___________________________________________________________
Geoffrey F4FXL / KC3FRA
My Tinytrak Stuff =>

 

Allen,

I do not know where the reset Pin but after a couple of tries I managed to enter the boot loader. There are some garbage characters being sent.
Hitting v to get the version only returns garbage.... Let see if I can upload the firmware ....




--
___________________________________________________________
Geoffrey F4FXL / KC3FRA
My Tinytrak Stuff =>

 

Ok I managed to upload the firmware.

Yet the configuration menu stills outputs garbage. Checked with different USB/Serial adapters, same result... Looks like the serial lines have an issue.

--
___________________________________________________________
Geoffrey F4FXL / KC3FRA
My Tinytrak Stuff =>

 

Are you sure you are uploading the correct firmware for the chip in the TT4?
You posting shows bootloader Version 1.2c:
> The file tt4_alpha_v067_1284.TT4 is for ATMEGA1284P based TinyTrak4s with
> bootloader version 1.2c, for builts sold after June 2010.

Probably, but just making sure.

Robert Giuliano
KB8RCO



On Sunday, December 18, 2022 at 04:17:19 AM EST, Geoffrey Merck <f4fxl@...> wrote:


Ok I managed to upload the firmware.

Yet the configuration menu stills outputs garbage. Checked with different USB/Serial adapters, same result... Looks like the serial lines have an issue.

--
___________________________________________________________
Geoffrey F4FXL / KC3FRA
My Tinytrak Stuff =>

 

double checked, it is the correct file....


--
___________________________________________________________
Geoffrey F4FXL / KC3FRA
My Tinytrak Stuff =>

 

Next episode:

I soldered some wires to MAX202 pins going directly to the CPU. I then connected a TTL/USB serial converter to these wires and were able to go into the menu of the TT4 and here it is, no more garbage !
Removed the wires and gave it a second try using the regular DB9 connector J2 on the tracker, and .... it is now working fine !... So I guess the actual issue were cold soldering on the MAX202 and countless years in a car broke them...

Next step is to test further if this was really the cause of the issue.

Picture of the test setup.




--
___________________________________________________________
Geoffrey F4FXL / KC3FRA
My Tinytrak Stuff =>

 

I have experienced some solder issues from various units as well, as I understand they are assembled over seas was the explanation I got ?

Nice repair!?


kelly

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