Psoc and I2C with PCA9685

Thank you, Bob. I will try and post what I find

I have made some changes, define the words you use for write/read operations and tested a bit but it seems to hang as soon as the program go into:

PWM_begin()>PWM_reset()>PWM_write8()>MOTOR_I2CMasterWriteByte(d)(HERE PROGRAM STOPS):

void PWM_write8(uint8_t reg, uint8_t d) {
  MOTOR_I2CMasterSendStart(_addr, I2C_WRITE_XFER_MODE);
  MOTOR_I2CMasterWriteByte(reg);
  MOTOR_I2CMasterWriteByte(d);   <------ HERE STOPS
  MOTOR_I2CMasterSendStop();
}

I don't know if I should activate something else. I also changed to byte mode I2C block.

Ok, I tested. It returns at first if. I2CMasterSendStart with 0x02 response code. If I remove Pullup resistors, I get a 0x04 code. I guess: MOTOR_I2C_MSTR_ERR_LB_NAK and MOTOR_I2C_MSTAT_ERR_ARB_LOST

Yes, I call PWM_ServoDriver. First thing in my code. I could replicate the 0x02 error. I have just got 0x04 since I post my previous message. 

I modified data rate to 100 and set slew rate to "Slow". I found those parameters in the datasheet. But this IC also supports 400 and fast rate. 

I double checked datasheet to see if the address was ok. I think it is. I have all address entries to 0, so it should be 0x40.

Yes, I fixed it. I saw it also when you pointed about the address. I have been reworking the library a bit basing on libraries for python I found on the internet and now I get a first error of 0x02 (NACK?) and then 0x04 always.

I don't have time today to check something else. Tomorrow I will try to test something else and I will post my updates. I willt ry also setting up another pioneer psoc as slave with address 0x40 and see what happens. 

Thank you bob. I got it working!. The board I was using (adafruit original) has 2 pullup resistors (10K) and that seems to be a bit too much for pionneer psoc board. I replaced them by 2.2k as you suggested and it started to work. As I said I tested with 4.7k jumping the 10k resistors but this value seems to be still too high.

I have to include the library in my project so I will change the code a bit to make it more readable (variable and function names) and also including some comments. After that I will update this topic with a copy of the project with a small example of use. Maybe it is useful for anyone who wants to test this IC.

Sorry for rescuing such an old post. I am still working on this, My company has had other priorities all this time. I am trying to finish it right now. 

We already have our final pcb board designed and prototyped. I am able to communicate to the first PCA9685 device (2 I2C slaves) with 0x40 address. 

It works while I don't try to communicate to the second one. As soon as I try this communication, neither the first one nor the second one works.

We are using the same core as my pioneer kit. CY8C4247LQI-BL483 56-QFN and pins we use from it are SCL P0[5] 25, and SDA P0[4] 24. 2.2K resistors for pull up.

Using 0x41 for the second device in I2C (The address we configured by its input pins) I get a fail in writeByte function. 0x02 MOTOR_I2C_MSTR_ERR_LB_NACK. If I set, for example, 0x42-0x45, I get a fail in SendStart function. also a 0x02. Can you give me any clue with this information? Or what should I check? 

Is there something related to close connection to one slave device before talking to another in I2C?

EDIT: I tried removing the call to the first I2C device. So the only one initialized and use is the seond one. I also get the 0x02 error in writeByte function.