Swap to the ItsyBitsy controller

hello_gradient/Cargo.lock

@@ -10,7 +10,7 @@ name = "atsamd-hal"
 version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "atsamd21e18a 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "atsamd21g18a 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "bitfield 0.13.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "cortex-m 0.5.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "embedded-hal 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -21,7 +21,7 @@ dependencies = [
 ]
 
 [[package]]
-name = "atsamd21e18a"
+name = "atsamd21g18a"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
@@ -84,7 +84,15 @@ dependencies = [
 ]
 
 [[package]]
-name = "gemma_m0"
+name = "hello_gradient"
+version = "0.1.0"
+dependencies = [
+ "itsybitsy_m0_lights 0.1.0",
+ "lights 0.1.0",
+]
+
+[[package]]
+name = "itsybitsy_m0"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
@@ -96,24 +104,16 @@ dependencies = [
 ]
 
 [[package]]
-name = "gemma_m0_lights"
+name = "itsybitsy_m0_lights"
 version = "0.1.0"
 dependencies = [
  "cortex-m 0.5.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "embedded-hal 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "gemma_m0 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "itsybitsy_m0 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "lights 0.1.0",
  "panic-halt 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "hello_gradient"
-version = "0.1.0"
-dependencies = [
- "gemma_m0_lights 0.1.0",
- "lights 0.1.0",
-]
-
 [[package]]
 name = "lights"
 version = "0.1.0"
@@ -257,14 +257,14 @@ dependencies = [
 [metadata]
 "checksum aligned 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d39da9b88ae1a81c03c9c082b8db83f1d0e93914126041962af61034ab44c4a5"
 "checksum atsamd-hal 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e0f224a1a946c4e817e87ed76d2dd48089bf545d35d4f30e83d579a87216681c"
-"checksum atsamd21e18a 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "139787a30d118dd09a2e9570f5404cf582b70afe9b53dd1194239f9be382b897"
+"checksum atsamd21g18a 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9f88795edced90ee7cf401714e60c3b7878d9fe9025059302e57a3b757f45e51"
 "checksum bare-metal 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "a3caf393d93b2d453e80638d0674597020cef3382ada454faacd43d1a55a735a"
 "checksum bitfield 0.13.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a260ed6b9f3ca16a4389390b1b1cd15a3bc0a9d3e63b1ef39f4978cec58a4e83"
 "checksum cortex-m 0.5.8 (registry+https://github.com/rust-lang/crates.io-index)" = "dab2164a0fc216781a47fc343347365112ae6917421d3fa4bac6faf0fbaaaec7"
 "checksum cortex-m-rt 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)" = "f69d2beca37acc3776c17201c9d1f8904fb9139fa3a4d2cf28c8436a07b21a88"
 "checksum cortex-m-rt-macros 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "d7ae692573e0acccb1579fef1abf5a5bf1d2f3f0149a22b16870ec9309aee25f"
 "checksum embedded-hal 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9880e55238830314d41d88f1ac7a819d495799c3cc3bc392cc172bab26428c33"
-"checksum gemma_m0 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "5e0b6ce273c7aee0101ad2ca75b5459b7498d6a09e241de34aaf51b7f1abe222"
+"checksum itsybitsy_m0 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c457960b339e016d68b64f928b7b2ea064574543573963642ee02b2039382d15"
 "checksum nb 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "69f380b5fe9fab8c0d7a6a99cda23e2cc0463bedb2cbc3aada0813b98496ecdc"
 "checksum panic-halt 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "de96540e0ebde571dc55c73d60ef407c653844e6f9a1e2fdbd40c07b9252d812"
 "checksum paste 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "f50392d1265092fbee9273414cc40eb6d47d307bd66222c477bb8450c8504f9d"

hello_gradient/Cargo.toml

@@ -11,4 +11,4 @@ debug = true
 
 [dependencies]
 lights = { path = "../lights" }
-lights_hal = { path = "../gemma_m0_lights", package = "gemma_m0_lights" }
+lights_hal = { path = "../itsybitsy_m0_lights", package = "itsybitsy_m0_lights" }

itsybitsy_m0_lights/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "itsybitsy_m0_lights"
+version = "0.1.0"
+authors = ["Tangent 128 <Tangent128@gmail.com>"]
+edition = "2018"
+
+[dependencies]
+cortex-m = { version = "0.5.8", features = ["inline-asm"] }
+embedded-hal = "0.2.2"
+itsybitsy_m0 = "0.2.1"
+lights = { path = "../lights" }
+panic-halt = "0.2"

itsybitsy_m0_lights/src/lib.rs

@@ -0,0 +1,83 @@
+#![no_std]
+
+extern crate cortex_m;
+extern crate embedded_hal;
+extern crate itsybitsy_m0 as hal;
+extern crate panic_halt;
+
+pub use cortex_m::asm::delay;
+pub use hal::entry;
+
+use core::u8;
+use embedded_hal::digital::OutputPin;
+use hal::{
+    clock::GenericClockController,
+    Peripherals
+};
+use lights::{
+    HardwareRgb,
+    Lights
+};
+
+pub fn boot() -> impl Lights<Pixel = HardwareRgb> {
+    let mut peripherals = Peripherals::take().unwrap();
+    let _clock = GenericClockController::with_internal_32kosc(
+        peripherals.GCLK,
+        &mut peripherals.PM,
+        &mut peripherals.SYSCTRL,
+        &mut peripherals.NVMCTRL
+    );
+
+    let mut pins = hal::Pins::new(peripherals.PORT);
+
+    NeopixelLights {
+        out: pins.d7.into_push_pull_output(&mut pins.port)
+    }
+}
+
+// approx. 20ns per clock cycle;
+const ZERO_HIGH_CYCLES: u32 = 11; // smidge above 200ns
+const ONE_HIGH_CYCLES: u32 = 35; // about 700ns
+const DATA_LOW_CYCLES: u32 = 25; // about 500ns
+const LATCH_CYCLES: u32 = 300; // about 6000ns
+
+pub struct NeopixelLights<T: OutputPin> {
+    out: T
+}
+
+impl<T: OutputPin> NeopixelLights<T> {
+    #[inline]
+    fn write(&mut self, bit: bool) {
+        self.out.set_high();
+        delay(if bit { ONE_HIGH_CYCLES } else { ZERO_HIGH_CYCLES });
+        self.out.set_low();
+        delay(DATA_LOW_CYCLES);
+    }
+
+    #[inline]
+    fn byte(&mut self, byte: u8) {
+        self.write(byte & 0x80 != 0);
+        self.write(byte & 0x40 != 0);
+        self.write(byte & 0x20 != 0);
+        self.write(byte & 0x10 != 0);
+        self.write(byte & 0x08 != 0);
+        self.write(byte & 0x04 != 0);
+        self.write(byte & 0x02 != 0);
+        self.write(byte & 0x01 != 0);
+    }
+}
+
+impl<T: OutputPin> Lights for NeopixelLights<T> {
+    type Pixel = HardwareRgb;
+
+    #[inline]
+    fn render(&mut self, rgb: &HardwareRgb) {
+        // GRB pixel order
+        self.byte(rgb.1);
+        self.byte(rgb.0);
+        self.byte(rgb.2);
+    }
+    fn latch(&mut self) {
+        delay(LATCH_CYCLES);
+    }
+}