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Stop PWM before assigning the new sequence

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I had introduced a small bug in my last PR where I assigned the sequence before stopping the PWM. I now stop the PWM before doing that now.

Also, corrected a math comment.
This commit is contained in:
huntc 2022-01-25 16:51:24 +11:00
parent 0549a9dbaa
commit c9f29534d6
3 changed files with 4 additions and 4 deletions
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4
embassy-nrf/src/pwm.rs
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@ -149,6 +149,8 @@ impl<'d, T: Instance> SequencePwm<'d, T> {
return Err(Error::SequenceTimesAtLeastOne); return Err(Error::SequenceTimesAtLeastOne);
} }
self.stop();
let r = T::regs(); let r = T::regs();
r.seq0 r.seq0
@ -165,8 +167,6 @@ impl<'d, T: Instance> SequencePwm<'d, T> {
.cnt .cnt
.write(|w| unsafe { w.bits(sequence.len() as u32) }); .write(|w| unsafe { w.bits(sequence.len() as u32) });
self.stop();
r.enable.write(|w| w.enable().enabled()); r.enable.write(|w| w.enable().enabled());
// defensive before seqstart // defensive before seqstart

2
examples/nrf/src/bin/pwm_sequence.rs
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@ -18,7 +18,7 @@ async fn main(_spawner: Spawner, p: Peripherals) {
let mut config = SequenceConfig::default(); let mut config = SequenceConfig::default();
config.prescaler = Prescaler::Div128; config.prescaler = Prescaler::Div128;
// 1 period is 1000 * (128/16mhz = 0.000008s = 0.008ms) = 8ms // 1 period is 1000 * (128/16mhz = 0.000008s = 0.008ms) = 8us
// but say we want to hold the value for 5000ms // but say we want to hold the value for 5000ms
// so we want to repeat our value as many times as necessary until 5000ms passes // so we want to repeat our value as many times as necessary until 5000ms passes
// want 5000/8 = 625 periods total to occur, so 624 (we get the one period for free remember) // want 5000/8 = 625 periods total to occur, so 624 (we get the one period for free remember)

2
examples/nrf/src/bin/pwm_sequence_ppi.rs
View File

@ -20,7 +20,7 @@ async fn main(_spawner: Spawner, p: Peripherals) {
let mut config = SequenceConfig::default(); let mut config = SequenceConfig::default();
config.prescaler = Prescaler::Div128; config.prescaler = Prescaler::Div128;
// 1 period is 1000 * (128/16mhz = 0.000008s = 0.008ms) = 8ms // 1 period is 1000 * (128/16mhz = 0.000008s = 0.008ms) = 8us
// but say we want to hold the value for 250ms 250ms/8 = 31.25 periods // but say we want to hold the value for 250ms 250ms/8 = 31.25 periods
// so round to 31 - 1 (we get the one period for free remember) // so round to 31 - 1 (we get the one period for free remember)
// thus our sequence takes 5 * 250ms or 1.25 seconds // thus our sequence takes 5 * 250ms or 1.25 seconds