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MAX1968: Improve STM32 ADC calibration consistency

This commit is contained in:
linuswck 2024-04-23 15:35:23 +08:00
parent b330f45260
commit c5efc6ca57
1 changed files with 11 additions and 1 deletions
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12
src/thermostat/max1968.rs
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@ -125,7 +125,17 @@ impl MAX1968 {
.default_sample_time(config::SampleTime::Cycles_480);
// Do not set reset RCCs as it causes other ADCs' clock to be disabled
let mut pins_adc1 = Adc::adc1(adc1, false, adc_config);
pins_adc1.calibrate();
// adc1.calibrate() fn only read REFINT once to assign the calibration value.
// It does not take the STM32F4's ADC Precision Limitation into account.
// AN4073: ADC Reading Dispersion can be reduced through Averaging
let mut vdda_mv: u32 = 0;
for _ in (0..512).rev() {
pins_adc1.calibrate();
vdda_mv += pins_adc1.reference_voltage();
}
vdda_mv = vdda_mv / 512 as u32;
pins_adc1.apply_config(adc_config.reference_voltage(vdda_mv));
let adc_config = AdcConfig::default()
.clock(config::Clock::Pclk2_div_8)