fw-rust: Create a print u8 function for setup

Create `print_u8()` helper function to print `u8` primitives to
lcd. Refactor contrast and backlight variables to also keep them in a
global `AtomicU8`.

firmware/rust/src/lcd.rs

@@ -5,6 +5,7 @@ use atmega_hal::{
     Spi,
 };
 use avr_device::interrupt;
+use core::convert::TryInto;
 use embedded_hal::{blocking::delay::DelayMs, spi::FullDuplex};
 use nb::block;
 
@@ -161,6 +162,39 @@ impl Lcd {
         }
     }
 
+    pub fn print_u8(&mut self, segment: u8, page: u8, digits: u8, data: u8) {
+        assert!(digits <= 3);
+        let mut delay = Delay::<MHz8>::new();
+
+        let mut array = [0usize; 3];
+        for (i, item) in array.iter_mut().enumerate() {
+            *item = ((data / 10_u8.pow(i.try_into().unwrap())) % 10).into();
+        }
+        array.reverse();
+
+        for i in 0..2 {
+            self.move_cursor(segment, page + i);
+
+            // TODO: This delay fixes issues, try find a better solution
+            delay.delay_ms(1_u8);
+            self.cd.set_high();
+
+            block!(self.spi.send(0x00)).unwrap();
+            block!(self.spi.send(0x00)).unwrap();
+            for j in 3 - digits..3 {
+                for segment in SYMBOL_TABLE[array[j as usize]][i as usize] {
+                    block!(self.spi.send(*segment)).unwrap();
+                }
+                block!(self.spi.send(0x00)).unwrap();
+            }
+            block!(self.spi.send(0x00)).unwrap();
+
+            // TODO: This delay fixes issues, try find a better solution
+            delay.delay_ms(1_u8);
+            self.cd.set_low();
+        }
+    }
+
     pub fn draw(&mut self, screen: &Screens) {
         interrupt::free(|_cs| {
             self.clear();

firmware/rust/src/main.rs

@@ -11,7 +11,7 @@ use atmega_hal::{
 };
 use avr_device::interrupt;
 use avr_eeprom::{eeprom, Eeprom};
-use core::sync::atomic::{AtomicBool, Ordering};
+use core::sync::atomic::{AtomicBool, AtomicU8, Ordering};
 use embedded_hal::{
     blocking::delay::DelayMs,
     spi::{Mode, Phase, Polarity},
@@ -28,8 +28,8 @@ use rotary::{Direction, Rotary};
 use screen::Screens;
 
 eeprom! {
-    static eeprom CONTRAST: u8 = 8;
+    static eeprom EEPROM_CONTRAST: u8 = 8;
-    static eeprom BACKLIGHT: u8 = 1;
+    static eeprom EEPROM_BACKLIGHT: u8 = 1;
 }
 
 pub enum Input {
@@ -42,6 +42,8 @@ pub enum Input {
 static UPDATE_ENCODER: AtomicBool = AtomicBool::new(false);
 static UPDATE_BUTTON: AtomicBool = AtomicBool::new(false);
 static UPDATE_TIMER: AtomicBool = AtomicBool::new(false);
+static CONTRAST: AtomicU8 = AtomicU8::new(0);
+static BACKLIGHT: AtomicU8 = AtomicU8::new(0);
 
 #[interrupt(atmega328p)]
 #[allow(non_snake_case)]
@@ -76,8 +78,8 @@ fn main() -> ! {
     let mut delay = Delay::<MHz8>::new();
 
     // Get contrast and backlight from EEPROM
-    let contrast = eeprom.read_value(&CONTRAST);
+    CONTRAST.store(eeprom.read_value(&EEPROM_CONTRAST), Ordering::SeqCst);
-    let backlight = eeprom.read_value(&BACKLIGHT);
+    BACKLIGHT.store(eeprom.read_value(&EEPROM_BACKLIGHT), Ordering::SeqCst);
 
     // Init display backlight
     let tc0 = dp.TC0;
@@ -92,7 +94,8 @@ fn main() -> ! {
         w
     });
     tc0.ocr0a.write(|w| unsafe { w.bits(255) });
-    tc0.ocr0b.write(|w| unsafe { w.bits(backlight) });
+    tc0.ocr0b
+        .write(|w| unsafe { w.bits(BACKLIGHT.load(Ordering::SeqCst)) });
     pins.pd5.into_output();
 
     // Init SPI
@@ -114,7 +117,7 @@ fn main() -> ! {
 
     // Init LCD
     let mut lcd = Lcd::new(spi, pins.pb0.into_output(), pins.pb1.into_output());
-    lcd.init(contrast);
+    lcd.init(CONTRAST.load(Ordering::SeqCst));
 
     // Init encoder
     let mut encoder = Rotary::new(pins.pb6.into_pull_up_input(), pins.pb7.into_pull_up_input());

firmware/rust/src/screen/setup.rs

@@ -1,5 +1,6 @@
 use super::{Home, Screen, Screens, Splash};
-use crate::{lcd::Lcd, Input};
+use crate::{lcd::Lcd, Input, BACKLIGHT, CONTRAST};
+use core::sync::atomic::Ordering;
 
 enum Selection {
     Contrast,
@@ -46,15 +47,18 @@ impl Setup {
 
 impl Screen for Setup {
     fn draw(&self, lcd: &mut Lcd) {
+        let contrast = CONTRAST.load(Ordering::SeqCst);
+        let backlight = BACKLIGHT.load(Ordering::SeqCst);
+
         match &self.active {
             Selection::Contrast => {
                 lcd.fill_area(0, 0, 33, 2, 0xFF);
                 lcd.print_inverted(33, 0, "SETUP");
                 lcd.fill_area(69, 0, 33, 2, 0xFF);
                 lcd.print_inverted(0, 2, "CONTRAST:");
-                lcd.print(89, 2, "00");
+                lcd.print_u8(89, 2, 2, contrast);
                 lcd.print(0, 4, "BACKLIGHT:");
-                lcd.print(83, 4, "000");
+                lcd.print_u8(83, 2, 3, backlight);
                 lcd.print(36, 6, "BACK");
             }
             Selection::Backlight => {
@@ -62,9 +66,9 @@ impl Screen for Setup {
                 lcd.print_inverted(33, 0, "SETUP");
                 lcd.fill_area(69, 0, 33, 2, 0xFF);
                 lcd.print(0, 2, "CONTRAST:");
-                lcd.print(89, 2, "00");
+                lcd.print_u8(89, 2, 2, contrast);
                 lcd.print_inverted(0, 4, "BACKLIGHT:");
-                lcd.print(83, 4, "000");
+                lcd.print_u8(83, 2, 3, backlight);
                 lcd.print(36, 6, "BACK");
             }
             Selection::Back => {
@@ -72,9 +76,9 @@ impl Screen for Setup {
                 lcd.print_inverted(33, 0, "SETUP");
                 lcd.fill_area(69, 0, 33, 2, 0xFF);
                 lcd.print(0, 2, "CONTRAST:");
-                lcd.print(89, 2, "00");
+                lcd.print_u8(89, 2, 2, contrast);
                 lcd.print(0, 4, "BACKLIGHT:");
-                lcd.print(83, 4, "000");
+                lcd.print_u8(83, 2, 3, backlight);
                 lcd.print_inverted(36, 6, "BACK");
             }
         }