The slave device of IIC is unable to raise the SCL response.

Forum|Forum|1 month ago
May 11, 2026
1 reply
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Here are the logs and waveforms. The slave device of IIC is unable to raise the SCL response. The data cannot be sent out either. The code is provided in the attachment.

HAL_I2C_AddrCallback: 开始接收数据
接收到字节[0]: 0x40
接收到字节[1]: 0x03
接收到字节[2]: 0x22
接收到字节[3]: 0xFE
接收到字节[4]: 0xBE
HAL_I2C_ListenCpltCallback: 开始接收数据
接收到字节[0]: 0x41
HAL_I2C_ListenCpltCallback: 开始发送数据
发送字节[0]: 0x05
发送字节[1]: 0x62
发送字节[2]: 0xFE
发送字节[3]: 0xBE
发送字节[4]: 0x30
发送字节[5]: 0x31

i2c_ipc.c

i2c.c

I2C

Best answer by AngusHZ

I'm aware of all of this. The cause of the problem lies in the usage issue of the HAL_I2C_Slave_Seq_Receive_IT interface.
The received byte count must be the same as the number sent by the host.
Adding or subtracting just one byte will cause the system to enter the ER interrupt.