embassy/embassy-stm32/src/adc/f1.rs

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use embassy_hal_internal::into_ref;
use embedded_hal_02::blocking::delay::DelayUs;
use crate::adc::{Adc, AdcPin, Instance, SampleTime};
use crate::rcc::get_freqs;
use crate::time::Hertz;
use crate::Peripheral;
pub const VDDA_CALIB_MV: u32 = 3300;
pub const ADC_MAX: u32 = (1 << 12) - 1;
// No calibration data for F103, voltage should be 1.2v
pub const VREF_INT: u32 = 1200;
pub struct Vref;
impl<T: Instance> AdcPin<T> for Vref {}
impl<T: Instance> super::sealed::AdcPin<T> for Vref {
fn channel(&self) -> u8 {
17
}
}
pub struct Temperature;
impl<T: Instance> AdcPin<T> for Temperature {}
impl<T: Instance> super::sealed::AdcPin<T> for Temperature {
fn channel(&self) -> u8 {
16
}
}
impl<'d, T: Instance> Adc<'d, T> {
pub fn new(adc: impl Peripheral<P = T> + 'd, delay: &mut impl DelayUs<u32>) -> Self {
into_ref!(adc);
T::enable();
T::reset();
T::regs().cr2().modify(|reg| reg.set_adon(true));
// 11.4: Before starting a calibration, the ADC must have been in power-on state (ADON bit = 1)
// for at least two ADC clock cycles
delay.delay_us((1_000_000 * 2) / Self::freq().0 + 1);
// Reset calibration
T::regs().cr2().modify(|reg| reg.set_rstcal(true));
while T::regs().cr2().read().rstcal() {
// spin
}
// Calibrate
T::regs().cr2().modify(|reg| reg.set_cal(true));
while T::regs().cr2().read().cal() {
// spin
}
// One cycle after calibration
delay.delay_us((1_000_000) / Self::freq().0 + 1);
Self {
adc,
sample_time: Default::default(),
}
}
fn freq() -> Hertz {
unsafe { get_freqs() }.adc
}
pub fn sample_time_for_us(&self, us: u32) -> SampleTime {
match us * Self::freq().0 / 1_000_000 {
0..=1 => SampleTime::Cycles1_5,
2..=7 => SampleTime::Cycles7_5,
8..=13 => SampleTime::Cycles13_5,
14..=28 => SampleTime::Cycles28_5,
29..=41 => SampleTime::Cycles41_5,
42..=55 => SampleTime::Cycles55_5,
56..=71 => SampleTime::Cycles71_5,
_ => SampleTime::Cycles239_5,
}
}
pub fn enable_vref(&self, _delay: &mut impl DelayUs<u32>) -> Vref {
T::regs().cr2().modify(|reg| {
reg.set_tsvrefe(true);
});
Vref {}
}
pub fn enable_temperature(&self) -> Temperature {
T::regs().cr2().modify(|reg| {
reg.set_tsvrefe(true);
});
Temperature {}
}
pub fn set_sample_time(&mut self, sample_time: SampleTime) {
self.sample_time = sample_time;
}
/// Perform a single conversion.
fn convert(&mut self) -> u16 {
T::regs().cr2().modify(|reg| {
reg.set_adon(true);
reg.set_swstart(true);
});
while T::regs().cr2().read().swstart() {}
while !T::regs().sr().read().eoc() {}
T::regs().dr().read().0 as u16
}
pub fn read(&mut self, pin: &mut impl AdcPin<T>) -> u16 {
Self::set_channel_sample_time(pin.channel(), self.sample_time);
T::regs().cr1().modify(|reg| {
reg.set_scan(false);
reg.set_discen(false);
});
T::regs().sqr1().modify(|reg| reg.set_l(0));
T::regs().cr2().modify(|reg| {
reg.set_cont(false);
reg.set_exttrig(true);
reg.set_swstart(false);
reg.set_extsel(crate::pac::adc::vals::Extsel::SWSTART);
});
// Configure the channel to sample
T::regs().sqr3().write(|reg| reg.set_sq(0, pin.channel()));
self.convert()
}
fn set_channel_sample_time(ch: u8, sample_time: SampleTime) {
let sample_time = sample_time.into();
if ch <= 9 {
T::regs().smpr2().modify(|reg| reg.set_smp(ch as _, sample_time));
} else {
T::regs().smpr1().modify(|reg| reg.set_smp((ch - 10) as _, sample_time));
}
}
}