max/embassy
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Merge #1024

Browse Source 
1024: stm32/adc: Remove voltage and temperature conversions r=Dirbaio a=GrantM11235

The current conversion utilities are confusing and a bit of a footgun. (Two out of the three examples got it wrong! They didn't measure vref at all, so all the conversions are completely wrong if vcca isn't 3.3v)

I think we should eventually have some sort of conversion utilities in the HAL, but for now I think it is best to just remove it and let the users do their own math.

cc `@chemicstry` 

Co-authored-by: Grant Miller <GrantM11235@gmail.com>
This commit is contained in:
bors[bot]
2022-10-26 19:44:06 +00:00
committed by GitHub
parent 01e23bf9dd 7a6732adcf
commit 7f499f3edc
7 changed files with 50 additions and 104 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
examples/stm32f7/src/bin/adc.rs
View File

@ -16,9 +16,19 @@ async fn main(_spawner: Spawner) {
let mut adc = Adc::new(p.ADC1, &mut Delay);
let mut pin = p.PA3;
let mut vrefint = adc.enable_vrefint();
let vrefint_sample = adc.read_internal(&mut vrefint);
let convert_to_millivolts = |sample| {
// From http://www.st.com/resource/en/datasheet/DM00273119.pdf
// 6.3.27 Reference voltage
const VREFINT_MV: u32 = 1210; // mV
(u32::from(sample) * VREFINT_MV / u32::from(vrefint_sample)) as u16
};
loop {
let v = adc.read(&mut pin);
info!("--> {} - {} mV", v, adc.to_millivolts(v));
info!("--> {} - {} mV", v, convert_to_millivolts(v));
Timer::after(Duration::from_millis(100)).await;
}
}