RE: NRF51 twi scanner: getting registers of i2c devices on bus

myNrfDoesntWork — Tue, 06 Aug 2019 03:52:09 GMT

This issue has been resolved, thank you!

RE: NRF51 twi scanner: getting registers of i2c devices on bus

myNrfDoesntWork — Mon, 05 Aug 2019 12:24:09 GMT

Hi I do not get any error codes that are not 0.

When I try running the unmodified TWI_Scanner example from SDK v12 with two i2c items on the NRF51 DK sda/scl lines (one at address 0x40, and one at 0x38) the scanning gets stuck on address 0x1.

If I plug in any single wire (SDA/SCL) into either P0.07 or P0.30, I get:

APP:INFO:TWI scanner.
APP:INFO:scanning: 0x1.

The 0x1 line doesn't print if I don't force a flush immediately after printing that line. I also tried using other pins and also different ways of powering the i2c items.

I debugged the unmodified twi_scanner code and it got stuck on a while loop in nrf_drv_twi.c (starting on line 615). I then traced the while loop calls to 'return true' being returned by the if statement on line 518 of the same nrf_drv_twi.c file.

@Edvin I will be getting a logic analyzer to do a further trace of the original twi_scanner code, but do you have any suggestions as to why the code I wrote does not read the registers of the i2c devices on the bus? I am still confused as to why it only returns error codes of 0 and readResults of 0. Thanks!

RE: NRF51 twi scanner: getting registers of i2c devices on bus

Edvin — Mon, 05 Aug 2019 12:00:32 GMT

Hello,

So you do not have any error codes (rt) != 0?

Have you tried the unmodified example, to see if that works? I see that there aren't any twi_scanner examples in SDK10, but maybe you can test the one in SDK12.3.0 just to see that all the HW is working as expected?

BR,

Edvin