New board - looses programming on power recycle

Created Thu, 17 Jul 2014 12:40:35 +0000 by muscas

muscas

Thu, 17 Jul 2014 12:40:35 +0000

Programming a simple blink application from the Pi to the ChipKIT kit Pi works until I power off the Pi and restart. The application is lost, and I have to upload again.

Is this a feature of the ChipKIT kit Pi or have I a faulty board?

majenko

Thu, 17 Jul 2014 13:58:34 +0000

It is certainly not a feature of the ckPi, no. I can't imagine the main chip being faulty, that's a very strange behaviour.

All I can surmise is that maybe it is stuck in bootloader mode. You upload a sketch and the bootloader terminates, running the sketch. You reset the board, and the bootloader loads again.

You should check the BOOTLOADER-EN button is actually functioning as it should and isn't permanently pressed.

EmbeddedMan

Thu, 17 Jul 2014 15:44:31 +0000

I concur. It sounds like the bootloader button is always pressed. If you remove jumper JP6 and power cycle, does your sketch run without being re-programmed? If so, then your BOOTLOAD-EN line is being pulled low.

*Brian

muscas

Fri, 18 Jul 2014 22:14:55 +0000

yes i think there is some board issue as I had it working briefly and now pressing the bootloader and then the reset etc causes the tx/rx lights to flash for a while and then stop, making it impossible to upload any sketch.

Is there a way to avoid the need to use the bootloader button sequence? Having to press this everytime you upload makes the board useless if you require 'field updates' of a sketch via remote access.

majenko

Fri, 18 Jul 2014 23:37:25 +0000

You could couple the MCLR and bootloader enable pins of the PIC32 to GPIO pins on the Pi. Link the MCLR through a 100nF capacitor so it turns a HIGH -> LOW transition into a pulse to reset the chip, and drive the BL-EN pin low at the same time, and you should enter the bootloader remotely.