fw-rust: Handle screens differently, use encoder

Handle the screens differently and implement rotary encoder support.

firmware/rust/src/main.rs

@@ -1,3 +1,4 @@
+#![feature(abi_avr_interrupt)]
 #![no_std]
 #![no_main]
 
@@ -9,9 +10,9 @@ use atmega_hal::{
     spi::{DataOrder, SerialClockRate, Settings, Spi},
     Peripherals,
 };
-use avr_device::interrupt::{self, Mutex};
+use avr_device::interrupt;
 use avr_eeprom::{eeprom, Eeprom};
-use core::cell::RefCell;
+use core::sync::atomic::{AtomicBool, Ordering};
 use embedded_hal::{
     blocking::delay::DelayMs,
     spi::{FullDuplex, Mode, Phase, Polarity},
@@ -19,6 +20,9 @@ use embedded_hal::{
 use nb::block;
 use panic_halt as _;
 
+mod rotary;
+use rotary::{Direction, Rotary};
+
 eeprom! {
     static eeprom CONTRAST: u8 = 8;
     static eeprom BACKLIGHT: u8 = 1;
@@ -345,20 +349,27 @@ impl Lcd {
         }
     }
 
-    fn screen(&mut self) {
-        self.clear();
+    fn draw(&mut self, screen: &Screens) {
+        interrupt::free(|_cs| {
+            self.clear();
 
-        interrupt::free(|cs| match &*SCREEN.borrow(cs).borrow() {
-            Screens::Splash(splash) => {
-                splash.draw(self);
+            match screen {
+                Screens::Splash(splash) => {
+                    splash.draw(self);
+                }
+                Screens::Home(home) => {
+                    home.draw(self);
+                }
             }
-            Screens::Home(home) => {
-                home.draw(self);
-            }
-        })
+        });
     }
 }
 
+enum Input {
+    Next,
+    Previous,
+}
+
 pub trait Draw {
     fn draw(&self, lcd: &mut Lcd);
 }
@@ -414,6 +425,41 @@ struct HomeScreen {
     active: HomeSelection,
 }
 
+impl HomeScreen {
+    fn input(&self, input: &Input) -> Screens {
+        match input {
+            Input::Next => match self.active {
+                HomeSelection::Ch1 => Screens::Home(HomeScreen {
+                    active: HomeSelection::Ch2,
+                }),
+                HomeSelection::Ch2 => Screens::Home(HomeScreen {
+                    active: HomeSelection::Ch3,
+                }),
+                HomeSelection::Ch3 => Screens::Home(HomeScreen {
+                    active: HomeSelection::Setup,
+                }),
+                HomeSelection::Setup => Screens::Home(HomeScreen {
+                    active: HomeSelection::Ch1,
+                }),
+            },
+            Input::Previous => match self.active {
+                HomeSelection::Ch1 => Screens::Home(HomeScreen {
+                    active: HomeSelection::Setup,
+                }),
+                HomeSelection::Ch2 => Screens::Home(HomeScreen {
+                    active: HomeSelection::Ch1,
+                }),
+                HomeSelection::Ch3 => Screens::Home(HomeScreen {
+                    active: HomeSelection::Ch2,
+                }),
+                HomeSelection::Setup => Screens::Home(HomeScreen {
+                    active: HomeSelection::Ch3,
+                }),
+            },
+        }
+    }
+}
+
 impl Draw for HomeScreen {
     fn draw(&self, lcd: &mut Lcd) {
         match &self.active {
@@ -450,112 +496,132 @@ enum Screens {
     Home(HomeScreen),
 }
 
-// TODO: Investigate if this should also be volatile
-static SCREEN: Mutex<RefCell<Screens>> = Mutex::new(RefCell::new(Screens::Splash(SplashScreen)));
+impl Screens {
+    fn input(&mut self, input: &Input) {
+        match self {
+            Screens::Splash(_) => {}
+            Screens::Home(home) => *self = home.input(input),
+        }
+    }
+}
+
+static UPDATE_ENCODER: AtomicBool = AtomicBool::new(false);
+
+#[interrupt(atmega328p)]
+#[allow(non_snake_case)]
+fn PCINT0() {
+    interrupt::free(|_cs| {
+        UPDATE_ENCODER.store(true, Ordering::SeqCst);
+    })
+}
 
 #[atmega_hal::entry]
 fn main() -> ! {
-    interrupt::free(|cs| {
-        // Get peripherals, pins, eeprom and delay
-        let dp = Peripherals::take().unwrap();
-        let pins = pins!(dp);
-        let eeprom = Eeprom::new(dp.EEPROM);
-        let mut delay = Delay::<MHz8>::new();
+    // Get peripherals, pins, eeprom and delay
+    let dp = Peripherals::take().unwrap();
+    let pins = pins!(dp);
+    let eeprom = Eeprom::new(dp.EEPROM);
+    let mut delay = Delay::<MHz8>::new();
 
-        // Get contrast and backlight from EEPROM
-        let contrast = eeprom.read_value(&CONTRAST);
-        let backlight = eeprom.read_value(&BACKLIGHT);
+    // Get contrast and backlight from EEPROM
+    let contrast = eeprom.read_value(&CONTRAST);
+    let backlight = eeprom.read_value(&BACKLIGHT);
 
-        // Init display backlight
-        let tc0 = dp.TC0;
-        tc0.tccr0a.write(|w| {
-            w.wgm0().pwm_fast();
-            w.com0b().match_clear();
-            w
-        });
-        tc0.tccr0b.write(|w| {
-            w.wgm02().set_bit();
-            w.cs0().prescale_64();
-            w
-        });
-        tc0.ocr0a.write(|w| unsafe { w.bits(255) });
-        tc0.ocr0b.write(|w| unsafe { w.bits(backlight) });
-        pins.pd5.into_output();
+    // Init display backlight
+    let tc0 = dp.TC0;
+    tc0.tccr0a.write(|w| {
+        w.wgm0().pwm_fast();
+        w.com0b().match_clear();
+        w
+    });
+    tc0.tccr0b.write(|w| {
+        w.wgm02().set_bit();
+        w.cs0().prescale_64();
+        w
+    });
+    tc0.ocr0a.write(|w| unsafe { w.bits(255) });
+    tc0.ocr0b.write(|w| unsafe { w.bits(backlight) });
+    pins.pd5.into_output();
 
-        // Init SPI
-        let (spi, _) = Spi::new(
-            dp.SPI,
-            pins.pb5.into_output(),
-            pins.pb3.into_output(),
-            pins.pb4.into_pull_up_input(),
-            pins.pb2.into_output(),
-            Settings {
-                data_order: DataOrder::MostSignificantFirst,
-                clock: SerialClockRate::OscfOver2,
-                mode: Mode {
-                    polarity: Polarity::IdleLow,
-                    phase: Phase::CaptureOnFirstTransition,
-                },
+    // Init SPI
+    let (spi, _) = Spi::new(
+        dp.SPI,
+        pins.pb5.into_output(),
+        pins.pb3.into_output(),
+        pins.pb4.into_pull_up_input(),
+        pins.pb2.into_output(),
+        Settings {
+            data_order: DataOrder::MostSignificantFirst,
+            clock: SerialClockRate::OscfOver2,
+            mode: Mode {
+                polarity: Polarity::IdleLow,
+                phase: Phase::CaptureOnFirstTransition,
             },
-        );
+        },
+    );
 
-        // Init LCD
-        let mut lcd = Lcd {
-            spi,
-            cd: pins.pb0.into_output(),
-            rst: pins.pb1.into_output(),
-        };
-        lcd.init(contrast);
+    // Init LCD
+    let mut lcd = Lcd {
+        spi,
+        cd: pins.pb0.into_output(),
+        rst: pins.pb1.into_output(),
+    };
+    lcd.init(contrast);
 
-        // Draw splash screen
-        lcd.screen();
+    // Init encoder
+    let mut encoder = Rotary::new(pins.pb6.into_pull_up_input(), pins.pb7.into_pull_up_input());
+    encoder.update();
 
-        // Show splash screen for a moment
-        delay.delay_ms(2000_u16);
+    // Enable interrupts for encoder // TODO: and switch
+    dp.EXINT.pcicr.write(|w| w.pcie().bits(0b0000_0001));
+    dp.EXINT.pcmsk0.write(|w| w.pcint().bits(0b1100_0000));
 
-        // Set home screen
-        let screen = SCREEN.borrow(cs);
-        *screen.borrow_mut() = Screens::Home(HomeScreen {
-            active: HomeSelection::Ch1,
-        });
+    // Create screen
+    let mut screen = Screens::Splash(SplashScreen);
 
-        // Draw screen
-        lcd.screen();
+    // Draw splash screen
+    lcd.draw(&screen);
 
-        // Show splash screen for a moment
-        delay.delay_ms(1000_u16);
+    // Show splash screen for a moment
+    delay.delay_ms(2000_u16);
 
-        // Demo select CH2
-        *screen.borrow_mut() = Screens::Home(HomeScreen {
-            active: HomeSelection::Ch2,
-        });
-
-        // Draw screen
-        lcd.screen();
-
-        // Show splash screen for a moment
-        delay.delay_ms(1000_u16);
-
-        // Demo select CH3
-        *screen.borrow_mut() = Screens::Home(HomeScreen {
-            active: HomeSelection::Ch3,
-        });
-
-        // Draw screen
-        lcd.screen();
-
-        // Show splash screen for a moment
-        delay.delay_ms(1000_u16);
-
-        // Demo select SETUP
-        *screen.borrow_mut() = Screens::Home(HomeScreen {
-            active: HomeSelection::Setup,
-        });
-
-        // Draw screen
-        lcd.screen();
+    // Set home screen
+    screen = Screens::Home(HomeScreen {
+        active: HomeSelection::Ch1,
     });
 
+    // Draw screen
+    lcd.draw(&screen);
+
+    let mut update_screen = false;
+
+    // Enable interrupts globally
+    unsafe { interrupt::enable() };
+
     #[allow(clippy::empty_loop)]
-    loop {}
+    loop {
+        if UPDATE_ENCODER.load(Ordering::SeqCst) {
+            interrupt::free(|_cs| {
+                delay.delay_ms(3_u8);
+
+                match encoder.update() {
+                    Direction::Clockwise => {
+                        screen.input(&Input::Next);
+                        update_screen = true;
+                    }
+                    Direction::CounterClockwise => {
+                        screen.input(&Input::Previous);
+                        update_screen = true;
+                    }
+                    Direction::None => {}
+                }
+                UPDATE_ENCODER.store(false, Ordering::SeqCst);
+            })
+        }
+
+        if update_screen {
+            lcd.draw(&screen);
+            update_screen = false;
+        }
+    }
 }

firmware/rust/src/rotary.rs

@@ -0,0 +1,51 @@
+use embedded_hal::digital::v2::InputPin;
+
+pub struct Rotary<A, B> {
+    pin_a: A,
+    pin_b: B,
+    state: u8,
+}
+
+pub enum Direction {
+    Clockwise,
+    CounterClockwise,
+    None,
+}
+
+impl<A, B> Rotary<A, B>
+where
+    A: InputPin,
+    B: InputPin,
+{
+    pub fn new(pin_a: A, pin_b: B) -> Self {
+        Self {
+            pin_a,
+            pin_b,
+            state: 0,
+        }
+    }
+
+    pub fn update(&mut self) -> Direction {
+        let a = self.pin_a.is_low();
+        let b = self.pin_b.is_low();
+
+        let new_state = match (a, b) {
+            (Ok(true), Ok(true)) => 0b00,
+            (Ok(true), Ok(false)) => 0b01,
+            (Ok(false), Ok(true)) => 0b10,
+            (Ok(false), Ok(false)) => 0b11,
+            _ => return Direction::None,
+        };
+
+        let direction = match (self.state, new_state) {
+            (0b10, 0b11) => Direction::Clockwise,
+            (0b01, 0b00) => Direction::Clockwise,
+            (0b01, 0b11) => Direction::CounterClockwise,
+            (0b10, 0b00) => Direction::CounterClockwise,
+            _ => Direction::None,
+        };
+
+        self.state = new_state;
+        direction
+    }
+}