Other Parts Discussed in Thread: TCA9539
I tested tca9539-Q1.
I read datasheet of tca9539.
So, I understand the slave address this ic 0x74 / (A1, A0 is LOW, 1110100)
and to use it only read function, 0xE9 (1110100 '1')
I just use it only read function.
P0 port 0,1,2,3,4,5
p1 Port 17,16,15,14,13
I use microcontroller stm series, using HAL library.
i2C setting is fast mode, clock speed 400kHz.
First, I send start message to slave.
HAL_I2C_Master_Transmit(&hi2c1, 0x74, data, 16, 10);
and than after 3ms delay
HAL_I2C_Master_Receive(&hi2c1, 0x74|0x01, data, 16, 10);
but, there is no reaction.
yellow is SDA, blue is SCL. I didin't know where is start signal, where is ack, SDA signal is really descrip 0x74?
how can I do?