[sdiy] STM32 vs WM8731

[rsdio at audiobanshee.com]

One good thing to have at times like these is some sort of bus analyzer. The Bus Pirate from Dangerous Prototypes can tell you what's really going on with the I2C bus, or for something fancier you could use the Saleae Logic.

On Feb 16, 2016, at 12:37 AM, "Rob" <rob at gmsn.co.uk> wrote:
> I’ve been trying to get a Nucleo-F411RE talking to a WM8731, but not having much luck getting it to communicate over I2C
>  
> I send the following from the STM32:
>  
>                 WM8731Status[0] = HAL_I2C_Master_Transmit(&hi2c1, 0x34, WM8731PowerOn1, 1, 10000);
>  
> But I don’t get an Ack from the WM8731:
>  
>                 https://www.dropbox.com/s/yhen98n17pyrqgr/Screenshot%202016-02-16%2008.22.15.png?dl=0
>  
> Here’s the schematic for the WM8731 setup:
>  
>                 https://www.dropbox.com/s/e6fkerkmf95ldzf/Screenshot%202016-02-16%2008.20.29.png?dl=0
>  
> I’m pretty sure everything on the STM32 side is setup correctly, and I’m working on the assumption that there’s not a lot to do with the WM8731. Once all the power is connected and the I2C mode and address pins are set low it should just receive I2C messages. I think the issue might be around the address, but I’ve tried all combinations I can think of.
>