I2C/TWIM doesn't work properly on nRF54L15DK

[Peter Langer Keysoft]

Hi,

we have nRF54L15DK (rev. 0.9.1). connected to MAX77655 via I2C.

I am trying to test i2c21 and i2c22 for writing data. I have tested it on different SCK and SDA on GPIO pins, but not all of them work. I respect the clock and port limitations for these I2C instances.

I sending this data

uint8_t i2c_tx_buffer[] = { 4, 7, 1, 5 };

ret = i2c_write_dt(&spec_i2c, i2c_tx_buffer, sizeof(i2c_tx_buffer));

I2c21 at (SCK. SDA) ~ (P1.03, P1.11)

I trying test on P2 (SCK, SDA) = (P2.06, P2.08) where P2.06 is clock pin - without success.

I2C21 and I2C22 at (SCK. SDA) ~ (P2.06, P2.08)

I found the combination (SCK, SDA) = (P1.08, P1.11) which works (see attached image), but I don't know why the combination (P1.03, P1.11) doesn't work, where P1.03 is also the clock pin.

Successful combination  (SCK, SDA) = (P1.08, P1.11)

Can you tell me why?
In the table 71 in nRF54L15_nRF54L10_nRF54L05_Datasheet_v0.8 at page 793 is list of dedicated pins, but TWI/I2C there are no present - is this correct?

SDK: v2.8.0

IDE: VSCode + nRF Connect plugin

PC: Windows 11 Pro

hardware: nRF54L15DK

BR

here is project and settings:

4452.TWI_USB.ZIP  

[Asbjørn]

Hello Peter,

P1.03/P1.11 ->  No obvious reason why this combination isn't working unless you have enabled the NFC  functionality or plugged in the NFC antenna?

P2.06/P2.08 -> These does overlap with the TRACE interface if you have enabled trace data debugging?

P1.08/P1.11 -> This looks very noisy and seemingly loaded with some capacitance. Are you using analog probes to capture the signals? Is the interface working if the probes are not on the pins?

How have you connected the nRF54L15 with the PMIC MAX77655, are you using some cables ebtween them?

Best regards

Asbjørn