nrf52832 I2C lines fail to work on pins 20 (SDA) and 21 (SCK)

RE: nrf52832 I2C lines fail to work on pins 20 (SDA) and 21 (SCK)

Jared — Thu, 29 Jun 2023 07:43:21 GMT

Hi,

I'm happy to hear that you were able to resolve the case and returned with the solution, it'll make it easier for others that struggle with the same issue,

regards

Jared

RE: nrf52832 I2C lines fail to work on pins 20 (SDA) and 21 (SCK)

Caver110 — Wed, 28 Jun 2023 14:46:58 GMT

Solved the issue! Your tests pointed me in the right direction; The issue was in vscode and was solved by adding "softreset" : true to the flash settings. Below are the steps i performed while working to a solution.

Here is the output running the lines you suggested. It appears pin 21 is still allocated as the reset pin so this is likely the issue (not i2c stuff)

I used nrf Connect for Desktop Programmer and erased the whole board. PSELRESET registers reset properly.

I placed an extra line of CONFIG_GPIO_AS_PINRESET=n in my proj.conf (just to ensure that it is set to "n" in the build)

Ran a pristine build, flashed my board and then re-ran the PSELRESET memory read. Still being allocated as reset pin

I was able to find another ticket now that i knew it was specifically a reset pin issue. Ticket = https://devzone.nordicsemi.com/f/nordic-q-a/100486/reset-pin-as-gpio Glen M suggested to visit https://nrfconnect.github.io/vscode-nrf-connect/guides/build_bind_tasks.html and add "softreset" : true to the settings.json file (I set it in the workspace.json as well).

PSELRESET registers AFTER building and flashing board. Reset button no longer reseting code on devkit (good).

I2C now working on P20 and P21. I can find the GPIO expander on the bus and it is responding to messages.

RE: nrf52832 I2C lines fail to work on pins 20 (SDA) and 21 (SCK)

Jared — Wed, 28 Jun 2023 10:44:31 GMT

Hi there,

Could you just double check that the GPIO peripheral indeed have access to the P0.21 and that it isn't allocated to the RESET circuitry? You can do that by reading out the PSELRESET[n] registers after flashing your application, you can use nRF Command Line Tools to read it out, like this:

nrfjprog --memrd 0x10001200


nrfjprog --memrd 0x10001204

Also, have you tried to just change P0.21 to something else and see if it works?

regards

Jared