Add allocator

Cargo.lock

@@ -15,12 +15,12 @@ dependencies = [
  "cortex-m",
  "cortex-m-rt",
  "cortex-m-rtic",
+ "embedded-alloc",
  "embedded-graphics",
  "embedded-hal",
  "embedded-time",
  "fugit",
  "nb 1.1.0",
- "numtoa",
  "panic-halt",
  "rp2040-boot2 0.3.0",
  "rp2040-hal",
@@ -206,6 +206,16 @@ version = "1.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7fcaabb2fef8c910e7f4c7ce9f67a1283a1715879a7c230ca9d6d1ae31f16d91"
 
+[[package]]
+name = "embedded-alloc"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8931e47e33c5d3194fbcf9cc82df0919193bd2fa40008f388eb1d28fd9c9ea6b"
+dependencies = [
+ "critical-section",
+ "linked_list_allocator",
+]
+
 [[package]]
 name = "embedded-dma"
 version = "0.2.0"
@@ -328,6 +338,12 @@ dependencies = [
  "either",
 ]
 
+[[package]]
+name = "linked_list_allocator"
+version = "0.10.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9afa463f5405ee81cdb9cc2baf37e08ec7e4c8209442b5d72c04cfb2cd6e6286"
+
 [[package]]
 name = "lock_api"
 version = "0.4.9"
@@ -442,12 +458,6 @@ dependencies = [
  "syn",
 ]
 
-[[package]]
-name = "numtoa"
-version = "0.2.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6aa2c4e539b869820a2b82e1aef6ff40aa85e65decdd5185e83fb4b1249cd00f"
-
 [[package]]
 name = "panic-halt"
 version = "0.2.0"

Cargo.toml

@@ -21,7 +21,7 @@ systick-monotonic = "1.0.1"
 embedded-time = "0.12.1"
 ssd1306 = "0.7.1"
 embedded-graphics = "0.7.1"
-numtoa = "0.2.4"
 smart-leds = "0.3.0"
 ws2812-pio = "0.6.0"
 waveshare-rp2040-zero = "0.6.0"
+embedded-alloc = "0.5.0"

src/main.rs

@@ -1,6 +1,7 @@
 #![no_std]
 #![no_main]
 
+use embedded_alloc::Heap;
 use panic_halt as _;
 
 use fugit::RateExtU32;
@@ -20,6 +21,9 @@ use embedded_graphics::{
 };
 use smart_leds::{SmartLedsWrite, RGB8};
 
+extern crate alloc;
+use alloc::format;
+
 use fugit::MicrosDurationU32;
 use hal::{
     gpio::{
@@ -32,6 +36,11 @@ use hal::{
     Adc,
 };
 
+#[global_allocator]
+static HEAP: Heap = Heap::empty();
+
+const HEAP_SIZE: usize = 1024;
+
 const XTAL_FREQ_HZ: u32 = 12_000_000u32;
 const MVG_AVG_COUNT: u16 = 20;
 
@@ -75,10 +84,12 @@ mod app {
 
     #[init()]
     fn init(c: init::Context) -> (Shared, Local, init::Monotonics) {
-        let mut resets = c.device.RESETS;
+        init_heap();
 
+        let mut resets = c.device.RESETS;
         let sio = hal::Sio::new(c.device.SIO);
         let mut watchdog = hal::Watchdog::new(c.device.WATCHDOG);
+
         let clocks = hal::clocks::init_clocks_and_plls(
             XTAL_FREQ_HZ,
             c.device.XOSC,
@@ -151,6 +162,12 @@ mod app {
         )
     }
 
+    fn init_heap() {
+        use core::mem::MaybeUninit;
+        static mut HEAP_MEM: [MaybeUninit<u8>; HEAP_SIZE] = [MaybeUninit::uninit(); HEAP_SIZE];
+        unsafe { HEAP.init(HEAP_MEM.as_ptr() as usize, HEAP_SIZE) }
+    }
+
     fn init_display(i2c: DisplayI2C) -> Display {
         let interface = I2CDisplayInterface::new(i2c);
         let mut display = Ssd1306::new(interface, DisplaySize128x64, DisplayRotation::Rotate0)
@@ -173,17 +190,12 @@ mod app {
 
     #[task(binds = TIMER_IRQ_0, priority = 1, shared = [alarm0, sensor_value], local = [display])]
     fn update_display(mut c: update_display::Context) {
-        let mut buf = [0u8; 20];
+        let text = c.shared.sensor_value.lock(|val| format!("{val}"));
-
-        let text = c.shared.sensor_value.lock(|val| {
-            use numtoa::NumToA;
-            val.numtoa_str(10, &mut buf)
-        });
 
         let display = c.local.display;
         display.clear();
         Text::with_alignment(
-            text,
+            &text,
             display.bounding_box().center(),
             MonoTextStyle::new(&FONT_10X20, BinaryColor::On),
             Alignment::Center,