Support for ''repeated start'' in STM32 HAL I2C library

[mduffy]

Posted on February 10, 2015 at 18:29

I am working with a slave I2C device (Kionix KX022 acccelerometer)  which uses a ''repeated start'' mechanism to send data requested by the master (STM32F405), e.g. to read two bytes of data (from register N and register N+1) the following sequence

Master                   Slave

---------------------    ------------------------STARTSlave Address + Write                         ACKN (starting register)                         ACKSTART (repeat)Slave Address + Read                         ACK                         DataACK                         DataNACKSTOPIt appears the STM32F4xx HAL I2C library does not support this directly, since HAL_I2C_Master_Transmit() sends STOP after the data.I just want to confirm this before writing some code (i.e. gluing together the HAL_I2C_Master_Transmit() and HAL_I2C_Master_Recieve() functions and removing the intervening STOP).Thanks in advance,Mike #i2c-stm32f4xx

[victagayun]

Thank you!

I was able to figure out also...

https://github.com/VictorTagayun/STM32_TC74/blob/3e3b1e4160d207ba5fc2dc65a64449f4d7f537d3/NUCLEO-G474RE_I2C_TC74/Core/Src/main.c#L165

https://github.com/VictorTagayun/STM32_TC74/blob/3e3b1e4160d207ba5fc2dc65a64449f4d7f537d3/NUCLEO-G474RE_I2C_TC74/Core/Src/main.c#L178