embassy/embassy-stm32/src/pwm/complementary_pwm.rs
2023-06-19 03:22:12 +02:00

251 lines
7.4 KiB
Rust

use core::marker::PhantomData;
use embassy_hal_common::{into_ref, PeripheralRef};
use stm32_metapac::timer::vals::Ckd;
use super::simple_pwm::*;
use super::*;
#[allow(unused_imports)]
use crate::gpio::sealed::{AFType, Pin};
use crate::gpio::AnyPin;
use crate::time::Hertz;
use crate::Peripheral;
pub struct ComplementaryPwmPin<'d, Perip, Channel> {
_pin: PeripheralRef<'d, AnyPin>,
phantom: PhantomData<(Perip, Channel)>,
}
macro_rules! complementary_channel_impl {
($new_chx:ident, $channel:ident, $pin_trait:ident, $complementary_pin_trait:ident) => {
impl<'d, Perip: CaptureCompare16bitInstance> ComplementaryPwmPin<'d, Perip, $channel> {
pub fn $new_chx(pin: impl Peripheral<P = impl $complementary_pin_trait<Perip>> + 'd) -> Self {
into_ref!(pin);
critical_section::with(|_| {
pin.set_low();
pin.set_as_af(pin.af_num(), AFType::OutputPushPull);
#[cfg(gpio_v2)]
pin.set_speed(crate::gpio::Speed::VeryHigh);
});
ComplementaryPwmPin {
_pin: pin.map_into(),
phantom: PhantomData,
}
}
}
};
}
complementary_channel_impl!(new_ch1, Ch1, Channel1Pin, Channel1ComplementaryPin);
complementary_channel_impl!(new_ch2, Ch2, Channel2Pin, Channel2ComplementaryPin);
complementary_channel_impl!(new_ch3, Ch3, Channel3Pin, Channel3ComplementaryPin);
complementary_channel_impl!(new_ch4, Ch4, Channel4Pin, Channel4ComplementaryPin);
pub struct ComplementaryPwm<'d, T> {
inner: PeripheralRef<'d, T>,
}
impl<'d, T: ComplementaryCaptureCompare16bitInstance> ComplementaryPwm<'d, T> {
pub fn new(
tim: impl Peripheral<P = T> + 'd,
_ch1: Option<PwmPin<'d, T, Ch1>>,
_ch1n: Option<ComplementaryPwmPin<'d, T, Ch1>>,
_ch2: Option<PwmPin<'d, T, Ch2>>,
_ch2n: Option<ComplementaryPwmPin<'d, T, Ch2>>,
_ch3: Option<PwmPin<'d, T, Ch3>>,
_ch3n: Option<ComplementaryPwmPin<'d, T, Ch3>>,
_ch4: Option<PwmPin<'d, T, Ch4>>,
_ch4n: Option<ComplementaryPwmPin<'d, T, Ch4>>,
freq: Hertz,
) -> Self {
Self::new_inner(tim, freq)
}
fn new_inner(tim: impl Peripheral<P = T> + 'd, freq: Hertz) -> Self {
into_ref!(tim);
T::enable();
<T as crate::rcc::sealed::RccPeripheral>::reset();
let mut this = Self { inner: tim };
this.inner.set_frequency(freq);
this.inner.start();
this.inner.enable_outputs(true);
this.inner
.set_output_compare_mode(Channel::Ch1, OutputCompareMode::PwmMode1);
this.inner
.set_output_compare_mode(Channel::Ch2, OutputCompareMode::PwmMode1);
this.inner
.set_output_compare_mode(Channel::Ch3, OutputCompareMode::PwmMode1);
this.inner
.set_output_compare_mode(Channel::Ch4, OutputCompareMode::PwmMode1);
this
}
pub fn enable(&mut self, channel: Channel) {
self.inner.enable_channel(channel, true);
self.inner.enable_complementary_channel(channel, true);
}
pub fn disable(&mut self, channel: Channel) {
self.inner.enable_complementary_channel(channel, false);
self.inner.enable_channel(channel, false);
}
pub fn set_freq(&mut self, freq: Hertz) {
self.inner.set_frequency(freq);
}
pub fn get_max_duty(&self) -> u16 {
self.inner.get_max_compare_value()
}
pub fn set_duty(&mut self, channel: Channel, duty: u16) {
assert!(duty < self.get_max_duty());
self.inner.set_compare_value(channel, duty)
}
/// Set the dead time as a proportion of max_duty
pub fn set_dead_time(&mut self, value: u16) {
let (ckd, value) = compute_dead_time_value(value);
self.inner.set_dead_time_clock_division(ckd);
self.inner.set_dead_time_value(value);
}
}
fn compute_dead_time_value(value: u16) -> (Ckd, u8) {
/*
Dead-time = T_clk * T_dts * T_dtg
T_dts:
This bit-field indicates the division ratio between the timer clock (CK_INT) frequency and the
dead-time and sampling clock (tDTS)used by the dead-time generators and the digital filters
(ETR, TIx),
00: tDTS=tCK_INT
01: tDTS=2*tCK_INT
10: tDTS=4*tCK_INT
T_dtg:
This bit-field defines the duration of the dead-time inserted between the complementary
outputs. DT correspond to this duration.
DTG[7:5]=0xx => DT=DTG[7:0]x tdtg with tdtg=tDTS.
DTG[7:5]=10x => DT=(64+DTG[5:0])xtdtg with Tdtg=2xtDTS.
DTG[7:5]=110 => DT=(32+DTG[4:0])xtdtg with Tdtg=8xtDTS.
DTG[7:5]=111 => DT=(32+DTG[4:0])xtdtg with Tdtg=16xtDTS.
Example if TDTS=125ns (8MHz), dead-time possible values are:
0 to 15875 ns by 125 ns steps,
16 us to 31750 ns by 250 ns steps,
32 us to 63us by 1 us steps,
64 us to 126 us by 2 us steps
*/
let mut error = u16::MAX;
let mut ckd = Ckd::DIV1;
let mut bits = 0u8;
for this_ckd in [Ckd::DIV1, Ckd::DIV2, Ckd::DIV4] {
let outdiv = match this_ckd {
Ckd::DIV1 => 1,
Ckd::DIV2 => 2,
Ckd::DIV4 => 4,
_ => unreachable!(),
};
// 127
// 128
// ..
// 254
// 256
// ..
// 504
// 512
// ..
// 1008
let target = value / outdiv;
let (these_bits, result) = if target < 128 {
(target as u8, target)
} else if target < 255 {
(64 + (target / 2) as u8, (target - target % 2))
} else if target < 508 {
(32 + (target / 8) as u8, (target - target % 8))
} else if target < 1008 {
(32 + (target / 16) as u8, (target - target % 16))
} else {
(u8::MAX, 1008)
};
let this_error = value.abs_diff(result * outdiv);
if error > this_error {
ckd = this_ckd;
bits = these_bits;
error = this_error;
}
match error {
0 => break,
_ => {}
}
}
(ckd, bits)
}
#[cfg(test)]
mod tests {
use super::{compute_dead_time_value, Ckd};
#[test]
fn test_compute_dead_time_value() {
struct TestRun {
value: u16,
ckd: Ckd,
bits: u8,
}
let fn_results = [
TestRun {
value: 1,
ckd: Ckd::DIV1,
bits: 1,
},
TestRun {
value: 125,
ckd: Ckd::DIV1,
bits: 125,
},
TestRun {
value: 245,
ckd: Ckd::DIV1,
bits: 64 + 245 / 2,
},
TestRun {
value: 255,
ckd: Ckd::DIV2,
bits: 127,
},
TestRun {
value: 400,
ckd: Ckd::DIV1,
bits: 32 + (400u16 / 8) as u8,
},
TestRun {
value: 600,
ckd: Ckd::DIV4,
bits: 64 + (600u16 / 8) as u8,
},
];
for test_run in fn_results {
let (ckd, bits) = compute_dead_time_value(test_run.value);
assert_eq!(ckd.0, test_run.ckd.0);
assert_eq!(bits, test_run.bits);
}
}
}