I2C Python Interface

[kdumont]

I'm writing an I2C interface in python in order to get a real-time stream from a peripheral device and do some additional processing. 

I have been able to get everything set up such that my peripheral ACKs my request. However, I'm curious for what your strategy is for handling the next packet depending on ACK/NACK.

Originally I was just using a digital read at the start of the transmit (Start + Address) and processing the response to detect ACK, then setting up the device for the next transmit (data). However, the USB back/forth is way too slow, so I'm assuming you set everything up in advance in Waveforms I2C to trigger on an ACK.

I tried a few methods of setting the output to trigger from I/O states, but I haven't been able to get it to work quite right (is there a way to force a trigger?).

Can you briefly explain the general flow for how you set the AD2 up to handle I2C as master in Waveforms?

 

Thanks,

Kyle

 

[attila]

Hi @kdumont

In WF SDK v.3.7.19 you can find UART, SPI, I2C functions.
Here you have an example: Digital_I2c.py

 

 

[attila]

Hi @kdumont

I have added UART, SPI, I2C master and UART receiver functions to the WF SDK, similar to WF application Protocol tool.
I hope to have time in the coming days to finalize the documentation and build a beta release with this.

[kdumont]

That's great news! In that case I will wait patiently.

[kdumont]

2 minutes ago, attila said:

Hi @kdumont

In WF SDK v.3.7.19 you can find UART, SPI, I2C functions.
Here you have an example: Digital_I2c.py

 

 

Just saw the update. Thanks. Will try it out.

[kdumont]

On 4/4/2018 at 12:46 PM, attila said:

Hi @kdumont

I have added UART, SPI, I2C master and UART receiver functions to the WF SDK, similar to WF application Protocol tool.
I hope to have time in the coming days to finalize the documentation and build a beta release with this.

Couple bugs:

 - The documentation says "DwfDigitalI2cWriteRead," but should be "FDwfDigitalI2cWriteRead"

 - The examples use "FDwfDigitalI2cFrequencySet" and "FDwfDigitalI2cTransfer" but should be "FDwfDigitalI2cRateSet" and "FDwfDigitalI2cWriteRead"

Other than that it works magically so far.

[kojak]

Hi @attila

This looks great. I have one question, can you add CAN bus or better also a LIN bus?

Thank you.

[attila]

Hi @kdumont

Thank you for the observation.
Please install v3.7.19-2 In this the examples and SPI functions are fixed. 

[attila]

Hi @kojak

I will try to add these in the near future.