SNS - Initial ADC Implementation

[H00pyFr00d]

Converted the adc.hpp from 2024. David and I discussed and realised that no ADC exclusive sensor was ever used last year, and so only the MUX code has ever been used

As such this is being temporarily abandoned, the work done thusfar (however minimal) is being kept here

(Update)

We determined that it was worth implementing, though because Embassy has ADC functionality most of the C++ implementation could be ignored

I've implemented something basic for ADC, but it's not been tested and will need looked at by somebody else

[linear]

HYPE-39 Implement ADC

[davidbeechey]

A few changes are needed now because of the change in repo structure. You'll need to move the lib/io/stm32l476rg/src/adc.rs into boards/stm32l476rg/src/io. (You need to open the boards/stm32l476rg folder in VS Code to get IDE features from Rust Analyzer.) Not sure about the channel...

[H00pyFr00d]

ADC implementation which passes cargo build, should (in theory) work

[davidbeechey]

Figured out the channel thing:

• embassy_stm32::adc::Adc::new takes in a peripheral which is the ADC on the board (there is more than one), e.g. p.ADC1
• Then the AnyAdcChannel input to Adc::blocking_read is a pin which implements the AnyAdcChannel trait for selected ADC which was passed into new.

Basically makes sense to rename pin to channel anyway but otherwise looks perfect. To instantiate it would be this (I've just checked that this compiles properly):

let adc = Adc::new(p.ADC1);
let hyped_adc = Stm32l476rgAdc::new(adc, p.PA0.degrade_adc());

Also fix typos + formatting, then mark as ready for review :)