Data reading from an STM32 pin with Python.

[andresbove]

Hi! I'm working with an STM32MP157F-DK2, it has a microprocessor A7 that's running Linux. I need to read the voltage of one of the pins. The pin configuration for the Analogical to Digital conversion it's made with the Linux terminal in the STM32.

How do I write in the Python code the order to "extract" the digitalized data from the kernell?

[tfcollins]

Not sure if libiio is the right place for your question. Does your ADC have an IIO driver? If you don't know you should probably reach out to ST's support.

-Travis

[andresbove]

Yes, it does have. I'm going to use this configuration.

https://wiki.st.com/stm32mpu/wiki/How_to_use_the_IIO_user_space_interface#How_to_do_a_simple_ADC_conversion_using_the_sysfs_interface

[tfcollins]

I would start here then: https://analogdevicesinc.github.io/libiio/v0.24/python/index.html

-Travis

[andresbove]

Thank you very much!

[andresbove]

If I want to use the Python Bindings in libiio for accessing and using the data of the ADC, do I must do it with the "buffer"? Following the hierarchy, should I create an "context" and a "device"? Like in this code:

https://analogdevicesinc.github.io/libiio/v0.20/python/_modules/iio_readdev.html#DataReader

Now, how do I tell the application what to read? Is the "device" the STM32 ADC pin?

[tfcollins]

IIO apps follow the hierarchy by creating a context, then find a device, and manipulate those device's channels.

Here is a basic example of an Analog Devices transceiver https://github.com/analogdevicesinc/plutosdr_scripts/blob/master/pluto.py

You should follow a similar flow.

-Travis

[andresbove]

So, for the context creation can I use ctx=iio.LocalContext and link all the devices that I'm going to use to that context? Because I think that I don't need a context working with an IP address

And for the "device part" could be something like this?
ctrl = ctx.find_device("48003000.adc:adc@0")
Following the below picture:

[tfcollins]

ctx = iio.Context() is the same as ctx = iio.LocalContext().

find_device looks at the name device attribute. Which would be 48003000.adc:adc@0 is your case.