From 8dfc9ba1a3e3f69aedf5bce748783fb6a8f5e92e Mon Sep 17 00:00:00 2001
From: rafael <rafael.koch@gmx.net>
Date: Mon, 21 Oct 2024 21:14:49 +0200
Subject: [PATCH] also add to the rp pwm example

---
 examples/rp/src/bin/pwm.rs   | 52 +++++++++++++++++++++++++++++++-----
 examples/rp23/src/bin/pwm.rs |  8 +++---
 2 files changed, 50 insertions(+), 10 deletions(-)

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.