It seems that i2c pin is not defined in configure.ac file, so i dont know how to use it #ifdef STM32F4_ENABLE_I2C1 #error Not implemented. #endif #ifdef STM32F4_ENABLE_I2C2 #error Not implemented. #endif -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.rtems.org/pipermail/users/attachments/20190402/22a4bf39/attachment.html>