Hi, we have chosen the AM5728 and the CY8C9520a GPIO expander (www.cypress.com/.../download) for a project. But unfortunately, we have problems with I2C. We have strong pull up in A0 pin of the expander, so according to the datasheet, the multiport address is 0x42 (01000010).
But we receive an error: communication timeout. We are running Linux in AM5728 idk. On the pins in I2C bus( SCL, SDA) we have also pull-ups. We tried different pull-ups. Now we have 2k2. It is working at 3.3 Volts.
Even the i2cdetect exports an error (communication timeout).
The connection diagram is simple but we are facing a fundamental problem.
With other peripherals, the i2c bus is working properly. The clock is in 400kHz.
Any ideas what is happening?
tnx in advance.
