embassy/examples/rp/src/bin/adc.rs
pennae b166ed6b78 rp: generalize adc inputs from pins to channels
this lets us treat pins and the temperature sensor uniformly using the
same interface. uniformity in turn lets us add more adc features without
combinatorial explosion of methods and types needed to handle them all.
2023-08-01 18:31:28 +02:00

50 lines
1.7 KiB
Rust

//! This example test the ADC (Analog to Digital Conversion) of the RS2040 pin 26, 27 and 28.
//! It also reads the temperature sensor in the chip.
#![no_std]
#![no_main]
#![feature(type_alias_impl_trait)]
use defmt::*;
use embassy_executor::Spawner;
use embassy_rp::adc::{Adc, Channel, Config, InterruptHandler};
use embassy_rp::bind_interrupts;
use embassy_rp::gpio::Pull;
use embassy_time::{Duration, Timer};
use {defmt_rtt as _, panic_probe as _};
bind_interrupts!(struct Irqs {
ADC_IRQ_FIFO => InterruptHandler;
});
#[embassy_executor::main]
async fn main(_spawner: Spawner) {
let p = embassy_rp::init(Default::default());
let mut adc = Adc::new(p.ADC, Irqs, Config::default());
let mut p26 = Channel::new_pin(p.PIN_26, Pull::None);
let mut p27 = Channel::new_pin(p.PIN_27, Pull::None);
let mut p28 = Channel::new_pin(p.PIN_28, Pull::None);
let mut ts = Channel::new_sensor(p.ADC_TEMP_SENSOR);
loop {
let level = adc.read(&mut p26).await.unwrap();
info!("Pin 26 ADC: {}", level);
let level = adc.read(&mut p27).await.unwrap();
info!("Pin 27 ADC: {}", level);
let level = adc.read(&mut p28).await.unwrap();
info!("Pin 28 ADC: {}", level);
let temp = adc.read(&mut ts).await.unwrap();
info!("Temp: {} degrees", convert_to_celsius(temp));
Timer::after(Duration::from_secs(1)).await;
}
}
fn convert_to_celsius(raw_temp: u16) -> f32 {
// According to chapter 4.9.5. Temperature Sensor in RP2040 datasheet
let temp = 27.0 - (raw_temp as f32 * 3.3 / 4096.0 - 0.706) / 0.001721;
let sign = if temp < 0.0 { -1.0 } else { 1.0 };
let rounded_temp_x10: i16 = ((temp * 10.0) + 0.5 * sign) as i16;
(rounded_temp_x10 as f32) / 10.0
}