diff --git a/examples/rp/src/bin/pwm.rs b/examples/rp/src/bin/pwm.rs index 26e233260..862a7da22 100644 --- a/examples/rp/src/bin/pwm.rs +++ b/examples/rp/src/bin/pwm.rs @@ -1,24 +1,36 @@ //! This example shows how to use PWM (Pulse Width Modulation) in the RP2040 chip. //! -//! The LED on the RP Pico W board is connected differently. Add a LED and resistor to another pin. +//! We demonstrate two ways of using PWM: +//! 1. Via config +//! 2. Via setting a duty cycle #![no_std] #![no_main] use defmt::*; use embassy_executor::Spawner; -use embassy_rp::pwm::{Config, Pwm}; +use embassy_rp::peripherals::{PIN_25, PIN_4, PWM_SLICE2, PWM_SLICE4}; +use embassy_rp::pwm::{Config, Pwm, SetDutyCycle}; use embassy_time::Timer; use {defmt_rtt as _, panic_probe as _}; #[embassy_executor::main] -async fn main(_spawner: Spawner) { +async fn main(spawner: Spawner) { let p = embassy_rp::init(Default::default()); + spawner.spawn(pwm_set_config(p.PWM_SLICE4, p.PIN_25)).unwrap(); + spawner.spawn(pwm_set_dutycycle(p.PWM_SLICE2, p.PIN_4)).unwrap(); +} - let mut c: Config = Default::default(); - c.top = 0x8000; +/// Demonstrate PWM by modifying & applying the config +/// +/// Using the onboard led, if You are using a different Board than plain Pico2 (i.e. W variant) +/// you must use another slice & pin and an appropriate resistor. +#[embassy_executor::task] +async fn pwm_set_config(slice4: PWM_SLICE4, pin25: PIN_25) { + let mut c = Config::default(); + c.top = 32_768; c.compare_b = 8; - let mut pwm = Pwm::new_output_b(p.PWM_SLICE4, p.PIN_25, c.clone()); + let mut pwm = Pwm::new_output_b(slice4, pin25, c.clone()); loop { info!("current LED duty cycle: {}/32768", c.compare_b); @@ -27,3 +39,31 @@ async fn main(_spawner: Spawner) { pwm.set_config(&c); } } + +/// Demonstrate PWM by setting duty cycle +/// +/// Using GP4 in Slice2, make sure to use an appropriate resistor. +#[embassy_executor::task] +async fn pwm_set_dutycycle(slice2: PWM_SLICE2, pin4: PIN_4) { + let mut c = Config::default(); + c.top = 32_768; + let mut pwm = Pwm::new_output_a(slice2, pin4, c.clone()); + + loop { + // 100% duty cycle, fully on + pwm.set_duty_cycle_fully_on().unwrap(); + Timer::after_secs(1).await; + + // 66% duty cycle. Expressed as simple percentage. + pwm.set_duty_cycle_percent(66).unwrap(); + Timer::after_secs(1).await; + + // 25% duty cycle. Expressed as 32768/4 = 8192. + pwm.set_duty_cycle(8_192).unwrap(); + Timer::after_secs(1).await; + + // 0% duty cycle, fully off. + pwm.set_duty_cycle_fully_off().unwrap(); + Timer::after_secs(1).await; + } +} diff --git a/examples/rp23/src/bin/pwm.rs b/examples/rp23/src/bin/pwm.rs index 1dd5ca3de..838eee625 100644 --- a/examples/rp23/src/bin/pwm.rs +++ b/examples/rp23/src/bin/pwm.rs @@ -59,12 +59,12 @@ async fn pwm_set_dutycycle(slice2: PWM_SLICE2, pin4: PIN_4) { pwm.set_duty_cycle_fully_on().unwrap(); Timer::after_secs(1).await; - // 50% duty cycle, half on. Expressed as simple percentage. - pwm.set_duty_cycle_percent(50).unwrap(); + // 66% duty cycle. Expressed as simple percentage. + pwm.set_duty_cycle_percent(66).unwrap(); Timer::after_secs(1).await; - // 25% duty cycle, quarter on. Expressed as (duty / max_duty) - pwm.set_duty_cycle(8_192 / c.top).unwrap(); + // 25% duty cycle. Expressed as 32768/4 = 8192. + pwm.set_duty_cycle(8_192).unwrap(); Timer::after_secs(1).await; // 0% duty cycle, fully off.