I had tried to use rpi as master to detect slave. The slave is MCU, using polling to answer rpi's request.
However, when I tried to use rip to check the slave address, using command :
i2cdetect -y 1
It couldn't detect anything.
After I changed the way, using interrupt in slave, tried " i2cdetect -y 1" again
It finally detects success. Rpi catch my slave address correct.
Why rpi uses i2cdetect slave can not detect the way of polling but interrupt can ?
I just know when a device sees its address it is meant to acknowledge its presence by pulling SDA low. If SDA isn't pulled low then the device is not present.
Is that mean when I using polling SDA is low, and change to interrupt SDA would be high when i2cdetect signal come?