Possible Ways to Brick?

[Nick]

Hello,

I have a board with an RFDuino on it which uses a Nordic nRF51822 internally. We are seeing a few of them auto-brick when the input voltage dips too low.

My first guess is that it is doing an EEPROM write even when the voltage dips or something, but I am just wondering what can brick these? Any known errata for this?

Basically it is running off of a big battery and as long as it stays above 2.9-ish volts, it works forever it seems. When it goes to 2.8v or so, sometimes it stops responding and then never turns on again. I haven't written the software but I am trying to get the code to look at.

[Carl]

We're seeing similar problems and hopefully we can help each other. We're working with RFDigital's newer chip Simblee and have a similar problem bricking modules that you're seeing with the RFDuino. We have a few that appear to have the RFDigital bootloader corrupted. We can use Nordic tools to connect and program the chip, but can no longer use the arduino tools. We have another one that we can program with arduino tools just fine but it won't run any code. I don't know if the actually execute portion of that chip's bootloader was corrupted or maybe the soft device was corrupted? Are you able to update code on your bricked modules? If you're able to figure anything else out, we'd appreciate it if you could let us know. Thanks.