nRF54L15 I2C target intermittently stops acknowledging until hard reset

RE: nRF54L15 I2C target intermittently stops acknowledging until hard reset

Edvin — Wed, 11 Nov 2026 14:50:44 GMT

Also, have you tried debugging the nRF (check logs and events)? Is there something happening on the last time that it worked, and is there anything happening on the first time that it doesn't work? any error messages in the log?

Is there some way for me to reproduce what you are seeing without an ESP? Can I use another nRF as the TWIM?

BR,

Edvin

RE: nRF54L15 I2C target intermittently stops acknowledging until hard reset

Turbo J — Wed, 11 Nov 2026 09:02:36 GMT

Those waveforms look suspiciously "sharp" for I²C bus lines. Triple check that the bus pins are set to open drain on both sides. You can usually see the "rounder" low-to-high flanks in a scope trace.

I don't know whether the ESP supports clock stretching - which the NRF chip may require in slave mode.

Other possible pitfall: Check that P0.0 and P0.1 are in the same power domain as TWIS30.