Basic overview of functionality

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Jake Goulding 2016-07-06 21:03:25 -04:00
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#
# Arduino
This library provides a set of reusable components for the Arduino Uno.
## Overview
### Register and bit definitions
```rust
use arduino::PORTB; // Register
use arduino::PORTB7; // Pin
```
### Prelude
Disable interrupts.
```rust
without_interrupts(|| {
unsafe { write_volatile(DDRB, 0xFF) }
})
```
### Timers
Configure a timer.
```rust
const CPU_FREQUENCY_HZ: u64 = 16_000_000;
const DESIRED_HZ_TIM1: f64 = 2.0;
const TIM1_PRESCALER: u64 = 1024;
const INTERRUPT_EVERY_1_HZ_1024_PRESCALER: u16 =
((CPU_FREQUENCY_HZ as f64 / (DESIRED_HZ_TIM1 * TIM1_PRESCALER as f64)) as u64 - 1) as u16;
timer1::Timer::new()
.waveform_generation_mode(timer1::WaveformGenerationMode::ClearOnTimerMatchOutputCompare)
.clock_source(timer1::ClockSource::Prescale1024)
.output_compare_1(Some(INTERRUPT_EVERY_1_HZ_1024_PRESCALER))
.configure();
```
Set up an interrupt handler that will be called when the timer fires.
```rust
#[no_mangle]
pub unsafe extern "avr-interrupt" fn _ivr_timer1_compare_a() {
let prev_value = read_volatile(PORTB);
write_volatile(PORTB, prev_value ^ PINB5);
}
```
### Hardware Serial Port
Configure the serial port.
```rust
const CPU_FREQUENCY_HZ: u64 = 16_000_000;
const BAUD: u64 = 9600;
const UBRR: u16 = (CPU_FREQUENCY_HZ / 16 / BAUD - 1) as u16;
serial::Serial::new(UBRR)
.character_size(serial::CharacterSize::EightBits)
.mode(serial::Mode::Asynchronous)
.parity(serial::Parity::Disabled)
.stop_bits(serial::StopBits::OneBit)
.configure();
```
Transmit a sequence of bytes.
```rust
for &b in b"OK" {
serial::transmit(b);
}
```
Read a byte if there's something available.
```rust
if let Some(b) = serial::try_receive() {
serial::transmit(b);
serial::transmit(b);
}
```