factored out keyboard file

src/keyboard.rs

@@ -0,0 +1,104 @@
+use arduino_hal::{adc::AdcChannel, hal::Atmega, pac::ADC, Adc};
+use ufmt::derive::uDebug;
+
+use crate::{DEBOUNCE_DEPTH, KEYBOARD_ADC_THRESHOLD};
+
+#[derive(uDebug, Clone, Copy, PartialEq, Eq)]
+pub enum KeyPress {
+    Up,
+    C,
+    Num(u8),
+    Mul,
+    Div,
+    Plus,
+    Minus,
+    Down,
+    E,
+}
+
+impl KeyPress {
+    fn map(display_no: usize, kn: bool, ko: bool) -> Option<KeyPress> {
+        match (display_no, kn, ko) {
+            (0, true, false) => Some(KeyPress::Num(1)),
+            (0, false, true) => Some(KeyPress::C),
+            (1, true, false) => Some(KeyPress::Num(5)),
+            (1, false, true) => Some(KeyPress::Div),
+            (2, true, false) => Some(KeyPress::Num(6)),
+            (2, false, true) => Some(KeyPress::Mul),
+            (3, true, false) => Some(KeyPress::Num(7)),
+            (3, false, true) => Some(KeyPress::Up),
+            (4, true, false) => Some(KeyPress::Num(8)),
+            (4, false, true) => Some(KeyPress::E),
+            (5, true, false) => Some(KeyPress::Num(9)),
+            (5, false, true) => Some(KeyPress::Num(0)),
+            (6, true, false) => Some(KeyPress::Num(2)),
+            (6, false, true) => Some(KeyPress::Down),
+            (7, true, false) => Some(KeyPress::Num(3)),
+            (7, false, true) => Some(KeyPress::Plus),
+            (8, true, false) => Some(KeyPress::Num(4)),
+            (8, false, true) => Some(KeyPress::Minus),
+            _ => None,
+        }
+    }
+}
+
+pub struct KeyReadout {
+    kn: bool,
+    ko: bool,
+}
+
+impl KeyReadout {
+    pub fn to_keypress(&self, display_no: usize) -> Option<KeyPress> {
+        KeyPress::map(display_no, self.kn, self.ko)
+    }
+}
+
+pub struct Keyboard<KN, KO> {
+    kn: KN,
+    ko: KO,
+}
+
+impl<KN: AdcChannel<Atmega, ADC>, KO: AdcChannel<Atmega, ADC>> Keyboard<KN, KO> {
+    pub fn new(kn: KN, ko: KO) -> Keyboard<KN, KO> {
+        Keyboard { kn, ko }
+    }
+
+    pub fn read(&self, adc: &mut Adc) -> Option<KeyReadout> {
+        let kn = adc.read_blocking(&self.kn);
+        let ko = adc.read_blocking(&self.ko);
+        if kn > KEYBOARD_ADC_THRESHOLD || ko > KEYBOARD_ADC_THRESHOLD {
+            Some(KeyReadout {
+                kn: kn > KEYBOARD_ADC_THRESHOLD,
+                ko: ko > KEYBOARD_ADC_THRESHOLD,
+            })
+        } else {
+            None
+        }
+    }
+}
+
+#[derive(Default)]
+pub struct Debounce {
+    record: [Option<KeyPress>; DEBOUNCE_DEPTH],
+    pos: usize,
+    last: Option<KeyPress>,
+}
+
+impl Debounce {
+    pub fn input(&mut self, key: Option<KeyPress>) -> Option<KeyPress> {
+        self.record[self.pos] = key;
+        self.pos += 1;
+        if self.pos >= self.record.len() {
+            self.pos = 0;
+        }
+        if self.record.iter().all(|hist| hist == &key) && self.last != key {
+            self.last = key;
+            key
+        } else if self.record.iter().all(|hist| hist == &None) {
+            self.last = None;
+            None
+        } else {
+            None
+        }
+    }
+}