What happens to nRF51822 if GPIO is set to source less current than required?

RE: What happens to nRF51822 if GPIO is set to source less current than required?

Jørn — Mon, 15 May 2017 07:38:59 GMT

The chip is flashed and debugged via the SWCLK and SWDIO pins. If you look at Figure 1. "Block diagram" of the product specification you will see that the SWCLK and SWDIO pins do not share hardware with the GPIO. I suspect the problem might lie somewhere in the "AHB multi layer" which lead out to the GPIO hardware, as this could potentially also affect the radio, as it uses the same bus through DMA to fetch data from RAM to transmit.

RE: What happens to nRF51822 if GPIO is set to source less current than required?

Elias — Fri, 12 May 2017 18:40:03 GMT

I'm on my third board, but I haven't had the courage to test the possible chip-frying code on it. I think I've discovered a different avenue for my main problem, so now, all I'm wondering is how much of a chip could possibly be damaged if it still interfaces with nRFgo Studio properly.

RE: What happens to nRF51822 if GPIO is set to source less current than required?

Jørn — Fri, 12 May 2017 09:40:50 GMT

Then it is possible the chip has been damaged. Do you have an additional custom board to test your code? This would eliminate any chance of it being a problem with the board, rather than a damaged chip.

RE: What happens to nRF51822 if GPIO is set to source less current than required?

Elias — Thu, 11 May 2017 20:26:19 GMT

The chip seems to still be programmable. I'm using an nRF51 DK as a debugger and nRFgo Studio tells me whether the target is the nRF51422 (on the DK) or the nRF51822 (on the other board) as expected. Reading the program out also seems to work.

I left the GPIO toggling (on a human-visible scale) for several seconds. I can't toggle any GPIOs or do BLE advertising, even though I've confirmed the programs to work with the nRF51 DK.

RE: What happens to nRF51822 if GPIO is set to source less current than required?

Jørn — Thu, 11 May 2017 08:58:16 GMT

Hello Elias Simon

There is no current limiting circuitry inside the chip. While sinking more current than the specification states is by no means optimal, it should be capable of doing it at least for a little while. Has the pin or chip failed to function properly after you did this? If it functions as it should, it is highly unlikely it took any damage.

Best regards

Jørn Frøysa