From ca5867ba36a6742f7464c0a186464338eb16f604 Mon Sep 17 00:00:00 2001
From: Edward Shen <code@eddie.sh>
Date: Fri, 16 May 2025 23:53:53 -0700
Subject: [PATCH] Add music on button press

---
 src/main.rs | 116 ++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 108 insertions(+), 8 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index dfcf4e9..6fe9971 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -8,10 +8,10 @@ use defmt::{info, unwrap};
 use embassy_executor::Spawner;
 use embassy_futures::select::{Either, select};
 use embassy_rp::bind_interrupts;
-use embassy_rp::config::Config;
 use embassy_rp::gpio::{self, Input};
-use embassy_rp::peripherals::{DMA_CH0, PIO0};
+use embassy_rp::peripherals::{DMA_CH0, PIN_20, PIO0, PWM_SLICE2};
 use embassy_rp::pio::{InterruptHandler, Pio};
+use embassy_rp::pwm::{self, Pwm, SetDutyCycle};
 use embassy_sync::blocking_mutex::raw::CriticalSectionRawMutex;
 use embassy_sync::channel::{Channel, Sender};
 use embassy_time::{Duration, Instant, Timer};
@@ -81,7 +81,7 @@ async fn button(
     loop {
         info!("Waiting for falling edge");
         input.wait_for_falling_edge().await;
-        sender.send(ChannelMessage::Refilled).await;
+        let _ = sender.try_send(ChannelMessage::Refilled);
         input.wait_for_high().await;
     }
 }
@@ -112,7 +112,7 @@ async fn main(spawner: Spawner) {
     //     Timer::after_secs(1).await;
     // }
 
-    let p = embassy_rp::init(Config::default());
+    let mut p = embassy_rp::init(embassy_rp::config::Config::default());
     let fw = include_bytes!("../embassy/cyw43-firmware/43439A0.bin");
     let clm = include_bytes!("../embassy/cyw43-firmware/43439A0_clm.bin");
 
@@ -152,10 +152,7 @@ async fn main(spawner: Spawner) {
     unwrap!(spawner.spawn(heartbeat(control)));
 
     unwrap!(spawner.spawn(button(
-        {
-            let input = Input::new(p.PIN_15, gpio::Pull::Up);
-            input
-        },
+        Input::new(p.PIN_15, gpio::Pull::Up),
         CHANNEL.sender()
     )));
 
@@ -178,7 +175,10 @@ async fn main(spawner: Spawner) {
                 info!("Water refilled received");
                 water_state.refill();
                 set_leds(water_state, &mut yellow_led, &mut red_led);
+                play_music(&mut p.PWM_SLICE2, &mut p.PIN_20).await;
                 timer = water_state.timer();
+                // only permit one message at a time
+                CHANNEL.clear();
             }
         }
     }
@@ -200,3 +200,103 @@ fn set_leds(water_state: WaterState, yellow_led: &mut Output, red_led: &mut Outp
         }
     }
 }
+
+async fn play_music(slice: &mut PWM_SLICE2, pin: &mut PIN_20) {
+    const SIXTHTEEN_NOTE_MILLIS: u64 = 100;
+
+    #[derive(PartialEq, Eq, Clone, Copy)]
+    #[repr(u16)]
+    enum Note {
+        Rest = 0,
+        C4 = 262,
+        D4 = 294,
+        E4 = 330,
+        F4 = 349,
+        G4 = 392,
+        A5 = 440,
+        #[allow(dead_code)]
+        B5 = 494,
+        C5 = 524,
+    }
+    #[expect(clippy::enum_glob_use)]
+    use Note::*;
+
+    #[repr(u8)]
+    enum Duration {
+        Sixthteenth = 1,
+        Eighth = 2,
+        DottedEighth = 3,
+        Quarter = 4,
+        Half = 8,
+    }
+    #[expect(clippy::enum_glob_use)]
+    use Duration::*;
+
+    const SONG: [(Note, Duration); 36] = [
+        (C4, DottedEighth),
+        (D4, Sixthteenth),
+        (E4, DottedEighth),
+        (F4, Sixthteenth),
+        (G4, Quarter),
+        (C5, Quarter),
+        //
+        (A5, Quarter),
+        (C5, Quarter),
+        (G4, Half),
+        //
+        (F4, Quarter),
+        (F4, Eighth),
+        (G4, Eighth),
+        (E4, Quarter),
+        (E4, Quarter),
+        //
+        (D4, Quarter),
+        (D4, Eighth),
+        (E4, Eighth),
+        (C4, Half),
+        //
+        (C4, DottedEighth),
+        (D4, Sixthteenth),
+        (E4, DottedEighth),
+        (F4, Sixthteenth),
+        (G4, Quarter),
+        (C5, Quarter),
+        //
+        (A5, Quarter),
+        (C5, Quarter),
+        (G4, Half),
+        //
+        (C5, Quarter),
+        (Rest, Eighth),
+        (A5, Eighth),
+        (G4, DottedEighth),
+        (G4, Sixthteenth),
+        (F4, Quarter),
+        //
+        (E4, Quarter),
+        (D4, Quarter),
+        (C4, Half),
+    ];
+
+    for (note, duration) in SONG {
+        let clock_freq_hz = embassy_rp::clocks::clk_sys_freq();
+        let divider = 16;
+        #[expect(clippy::cast_possible_truncation)]
+        let period = clock_freq_hz.saturating_div(note as u32 * u32::from(divider)) as u16 - 1;
+
+        let mut c = pwm::Config::default();
+        c.top = period;
+        c.divider = divider.into();
+
+        let mut pwm = Pwm::new_output_a(&mut *slice, &mut *pin, c.clone());
+
+        if note == Rest {
+            let _ = pwm.set_duty_cycle_fully_off();
+        } else {
+            let _ = pwm.set_duty_cycle_percent(50);
+        }
+        Timer::after_millis(duration as u64 * SIXTHTEEN_NOTE_MILLIS).await;
+        let _ = pwm.set_duty_cycle_fully_off();
+        Timer::after_millis(20).await;
+    }
+}