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1

TinyDuino Processors & TinyShields / Re: Cannot reprogram my Tinyduino

« on: April 21, 2016, 04:13:20 PM »

Many thanks John.
That link didn't directly solve my issue but it gave me a good hint: I am suspicious that the USB shield is not sending a reset to the processor when trying to start uploading the sketch.
I'll have to get my scope hooked up to it to check this, but I'm thinking that perhaps if my original sketch is chucking too much TX data towards the PC, and isn't being reset, then maybe this is preventing the uploader from establishing comms.
I found that if I unplug the board, wait a minute then plug it back in and quickly try to upload my sketch, it works reliably.
I added a big start-up delay() in my sketch so it doesn't do anything for 5 seconds after power-up, and magically it's become easier to upload sketches.
Annoying, but at least I hadn't somehow bricked the board, which was my main concern.

If I can establish what happens with the reset signal, I'll post the details here...

2

TinyDuino Processors & TinyShields / Cannot reprogram my Tinyduino

« on: April 20, 2016, 05:13:41 PM »

I'm new to Arduinos in all forms, though I have a lot of experience with PIC uCs from years of developing embedded systems.
I bought a Tinyduino processor board, SD card shield, GPS shield and USB shield, stacking them up in that order.
I'm programming on a Mac. First off, I found I had to use Arduino 1.6.5 because newer versions did not seem to detect the board when I plugged it in via USB.
My first sketch (perhaps foolishly) was not one of the examples but one that I wrote myself. It was supposed to create a couple of files on the SD card,
then loop forever pinging 'A' to the hardware serial device and expecting a series of 22 bytes in return, which it would then dump to a file on the SD card.
I formatted a 2GB Sandisk SD Card using the recommended formatter.
The sketch uploaded OK and ran, and when I opened the serial monitor, I saw 'A's being streamed to the PC.
After powering it off and putting the SD card in my Mac, I found there were no files on the card.
That was last night and I had to stop at that point.
Today I made some code edits to add diagnostics to the card initialisation, but now when I try to upload the modified sketch, nothing much happens.
On the USB shield, the orange TX light is flickering continuously, but never the RX light.
After about 10-15 minutes the log messages in the editor window show:

Sketch uses 11,488 bytes (37%) of program storage space. Maximum is 30,720 bytes.
Global variables use 1,364 bytes (66%) of dynamic memory, leaving 684 bytes for local variables. Maximum is 2,048 bytes.
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0xe0
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0xe0
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x00
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x00
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0xe0
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x00
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0xe0
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0xe0
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x00
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0xe0
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x41
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x41
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x41
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x41
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x41
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x41
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x41
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x41
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x41
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x41


Hmm.... 0x41 == 'A'. So I open up the serial monitor and my original program still seems to be running, pumping out 'A' continuously.

I have also tried building and uploading the SD card info example sketch, but that also fails to upload.

So, does anyone know why the new sketch won't upload?

I have overwritten the original sketch but am happy to share the latest version if it is relevant (some significant edits mean that it's not too similar to the version I did upload though).

Many thanks.