rp-hal-boards/boards/rp-pico/examples/pico_pwm_servo.rs
luca zulian 3842ef2700
Add Pico PWM micro servo example (#346)
* Add micro servo with pwm working example

Signed-off-by: lucazulian <lucagiuggia@gmail.com>

* Add duty value suggestion

Signed-off-by: lucazulian <lucagiuggia@gmail.com>

* Fix code formatting

* Use CountDown instead of Delay
2022-05-26 22:25:49 +10:00

120 lines
3.3 KiB
Rust

//! # Pico PWM Micro Servo Example
//!
//! Moves the micro servo on a Pico board using the PWM peripheral.
//!
//! This will move in different positions the motor attached to GP1.
//!
//! See the `Cargo.toml` file for Copyright and license details.
#![no_std]
#![no_main]
// The macro for our start-up function
use cortex_m_rt::entry;
use cortex_m::prelude::*;
// GPIO traits
use embedded_hal::PwmPin;
// Traits for converting integers to amounts of time
use embedded_time::duration::Extensions;
// Ensure we halt the program on panic (if we don't mention this crate it won't
// be linked)
use panic_halt as _;
// A shorter alias for the Peripheral Access Crate, which provides low-level
// register access
use rp_pico::hal::pac;
// A shorter alias for the Hardware Abstraction Layer, which provides
// higher-level drivers.
use rp_pico::hal;
/// Entry point to our bare-metal application.
///
/// The `#[entry]` macro ensures the Cortex-M start-up code calls this function
/// as soon as all global variables are initialised.
///
/// The function configures the RP2040 peripherals, then fades the LED in an
/// infinite loop.
#[entry]
fn main() -> ! {
// Grab our singleton objects
let mut pac = pac::Peripherals::take().unwrap();
// Set up the watchdog driver - needed by the clock setup code
let mut watchdog = hal::Watchdog::new(pac.WATCHDOG);
// Configure the clocks
//
// The default is to generate a 125 MHz system clock
let _clocks = hal::clocks::init_clocks_and_plls(
rp_pico::XOSC_CRYSTAL_FREQ,
pac.XOSC,
pac.CLOCKS,
pac.PLL_SYS,
pac.PLL_USB,
&mut pac.RESETS,
&mut watchdog,
)
.ok()
.unwrap();
// Configure the Timer peripheral in count-down mode
let timer = hal::Timer::new(pac.TIMER, &mut pac.RESETS);
let mut count_down = timer.count_down();
// The single-cycle I/O block controls our GPIO pins
let sio = hal::Sio::new(pac.SIO);
// Set the pins up according to their function on this particular board
let pins = rp_pico::Pins::new(
pac.IO_BANK0,
pac.PADS_BANK0,
sio.gpio_bank0,
&mut pac.RESETS,
);
// Init PWMs
let mut pwm_slices = hal::pwm::Slices::new(pac.PWM, &mut pac.RESETS);
// Configure PWM0
let pwm = &mut pwm_slices.pwm0;
pwm.set_ph_correct();
pwm.set_div_int(20u8); // 50 hz
pwm.enable();
// Output channel B on PWM0 to the GPIO1 pin
let channel = &mut pwm.channel_b;
channel.output_to(pins.gpio1);
// Infinite loop, moving micro servo from one position to another.
// You may need to adjust the pulse width since several servos from
// different manufacturers respond differently.
loop {
// move to 0°
channel.set_duty(2500);
count_down.start(400.milliseconds());
let _ = nb::block!(count_down.wait());
// 0° to 90°
channel.set_duty(3930);
count_down.start(400.milliseconds());
let _ = nb::block!(count_down.wait());
// 90° to 180°
channel.set_duty(7860);
count_down.start(400.milliseconds());
let _ = nb::block!(count_down.wait());
// 180° to 90°
channel.set_duty(3930);
count_down.start(400.milliseconds());
let _ = nb::block!(count_down.wait());
}
}
// End of file