Only use safe functions in main

Makefile

@@ -1,9 +1,12 @@
 build:
-	@xargo build --release
+	xargo build --release --target thumbv7em-none-eabi
 
 flash: build
 	arm-none-eabi-objcopy -O ihex -R .eeprom target/thumbv7em-none-eabi/release/teensy3-rs-demo target/hex
-	teensy-loader-cli -w -s --mcu=mk20dx256 target/hex
+	teensy-loader-cli -w -s --mcu=mk64fx512 target/hex
+
+monitor:
+	screen /dev/ttyACM0 115200
 
 clean:
 	xargo clean

src/main.rs

@@ -4,38 +4,45 @@
 #[macro_use]
 extern crate teensy3;
 
-use teensy3::bindings;
 use teensy3::serial::Serial;
+use teensy3::util::{
+    digital_write,
+    analog_read,
+    analog_write,
+    pin_mode,
+    delay,
+    PinMode
+};
+
+mod motor;
 
 #[no_mangle]
-pub unsafe extern fn main() {
+pub extern fn main() {
     // Blink Loop
 
-    bindings::pinMode(13, bindings::OUTPUT as u8);
-    bindings::digitalWrite(13, bindings::LOW as u8);
-    let mut ser = Serial{};
+    pin_mode(13, PinMode::Output);
+    pin_mode(14, PinMode::Input);
+    digital_write(13, true);
 
-    loop {
-        // Show we are alive
-        alive();
+    let motor = motor::HBridge::new(20, (19, 18));
 
-        // If the serial write fails, we will halt (no more alive blinks)
-        hello(&ser).unwrap();
+    let ser = Serial{};
 
-        // Don't spam the console
-        bindings::delay(1000);
+    loop {
+        motor.set_state(motor::HBridgeState::Forward, (analog_read(14) / 4) as u8);
+        delay(10);
     }
 }
 
 /// Blink the light twice to know we're alive
-pub unsafe fn alive() {
+pub fn alive() {
     for _ in 0..2 {
-        bindings::digitalWrite(13, bindings::LOW as u8);
-        bindings::delay(200);
-        bindings::digitalWrite(13, bindings::HIGH as u8);
-        bindings::delay(200);
-        bindings::digitalWrite(13, bindings::LOW as u8);
-        bindings::delay(200);
+        digital_write(13, false);
+        delay(200);
+        digital_write(13, true);
+        delay(200);
+        digital_write(13, false);
+        delay(200);
     }
 }
 

src/motor.rs

@@ -0,0 +1,64 @@
+use teensy3::util::{
+    digital_write,
+    analog_write,
+    pin_mode,
+    PinMode
+};
+
+
+/**
+  Struct for controlling a SN754410 H bridge motor driver
+*/
+pub struct HBridge
+{
+    enable_pin: u8,
+    input_pins: (u8, u8),
+}
+
+pub enum HBridgeState {
+    Disable,
+    Forward,
+    Backward,
+}
+
+
+impl HBridge
+{
+    pub fn new(enable_pin: u8, input_pins: (u8, u8)) -> HBridge
+    {
+        pin_mode(enable_pin, PinMode::Output);
+        pin_mode(input_pins.0, PinMode::Output);
+        pin_mode(input_pins.1, PinMode::Output);
+
+        HBridge {
+            enable_pin: enable_pin,
+            input_pins: input_pins,
+        }
+    }
+
+    pub fn set_state(&self, state: HBridgeState, speed: u8)
+    {
+        match state
+        {
+            HBridgeState::Disable =>
+            {
+                digital_write(self.enable_pin, false);
+            },
+            HBridgeState::Forward =>
+            {
+                analog_write(self.enable_pin, speed);
+                digital_write(self.input_pins.0, true);
+                digital_write(self.input_pins.1, false);
+            },
+            HBridgeState::Backward =>
+            {
+                analog_write(self.enable_pin, speed);
+                digital_write(self.enable_pin, true);
+                digital_write(self.input_pins.0, false);
+                digital_write(self.input_pins.1, true);
+            }
+        }
+    }
+}
+
+