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STM32F4 I2C send NACK if received byte == 0

Question asked by noeltner.moritz on May 13, 2015
Latest reply on May 15, 2015 by flown.tesca
Hi everyone,

I want to interface an STM32F429IIT to a SI4735 radio chip using the I2C interface. The SI4735 programming manual says, the status bytes should be read after sending a command.
My problem is, that the first status byte may be zero (or at least one certain bit may be zero) which indicates the remaining status bytes are not ready for reading. In this case, the system controller (in my case the STM32) should send a NACK after the reception of the first byte and end the transmission.
How can I do this? To my understanding, the ACK bit in CR1 has to be cleared before reception of a byte in order to send a NACK when it is received.

Best regards,
Moritz Nöltner

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