Hello,
I am working on an STM32C011 (Nucleo-like custom board) and trying to use I2C1 with the following pinout:
PB7 → I2C1_SCL (AF14)
PC14 → I2C1_SDA (AF14)
According to the reference manual / datasheet, PC14 can be mapped as I2C1_SDA (AF14).
I connected an SHTC3 humidity/temperature sensor (address 0x70) to these lines with 4.7k pull-ups.
Problem:
My I²C scanner code never detects the SHTC3 (always NACK at 0x70).
If I configure I²C on PB6/PB7 instead, the scanner works.
GPIO PC14 seems not to toggle as SDA when I try transactions.
I suspect this might be related to PC14 also being used for LSE (OSC32_IN). In CubeMX, I set LSE = Disabled under RCC.
But I still wonder if PC14 can reliably be used for I²C, or if there are silicon limitations when LSE is involved.
Questions:
Is PC14 fully usable as I²C SDA on STM32C0 when LSE is disabled?
Has anyone successfully used I²C1 on PB7 (SCL) + PC14 (SDA)?
Could this be a hardware limitation / errata, or am I missing a CubeMX clock configuration detail?
Any feedback or working examples would be greatly appreciated
