69 lines
2.3 KiB
Rust
69 lines
2.3 KiB
Rust
#![no_std]
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#![no_main]
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#![feature(type_alias_impl_trait)]
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use defmt::info;
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use embassy_executor::Spawner;
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use embassy_nrf::interrupt;
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use embassy_nrf::saadc::{ChannelConfig, Config, Saadc, SamplerState};
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use embassy_nrf::timer::Frequency;
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use embassy_time::Duration;
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use {defmt_rtt as _, panic_probe as _};
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// Demonstrates both continuous sampling and scanning multiple channels driven by a PPI linked timer
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#[embassy_executor::main]
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async fn main(_p: Spawner) {
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let mut p = embassy_nrf::init(Default::default());
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let config = Config::default();
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let channel_1_config = ChannelConfig::single_ended(&mut p.P0_02);
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let channel_2_config = ChannelConfig::single_ended(&mut p.P0_03);
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let channel_3_config = ChannelConfig::single_ended(&mut p.P0_04);
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let mut saadc = Saadc::new(
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p.SAADC,
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interrupt::take!(SAADC),
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config,
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[channel_1_config, channel_2_config, channel_3_config],
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);
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// This delay demonstrates that starting the timer prior to running
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// the task sampler is benign given the calibration that follows.
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embassy_time::Timer::after(Duration::from_millis(500)).await;
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saadc.calibrate().await;
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let mut bufs = [[[0; 3]; 500]; 2];
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let mut c = 0;
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let mut a: i32 = 0;
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saadc
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.run_task_sampler(
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&mut p.TIMER0,
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&mut p.PPI_CH0,
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&mut p.PPI_CH1,
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Frequency::F1MHz,
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1000, // We want to sample at 1KHz
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&mut bufs,
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move |buf| {
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// NOTE: It is important that the time spent within this callback
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// does not exceed the time taken to acquire the 1500 samples we
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// have in this example, which would be 10us + 2us per
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// sample * 1500 = 18ms. You need to measure the time taken here
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// and set the sample buffer size accordingly. Exceeding this
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// time can lead to the peripheral re-writing the other buffer.
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for b in buf {
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a += b[0] as i32;
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}
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c += buf.len();
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if c > 1000 {
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a = a / c as i32;
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info!("channel 1: {=i32}", a);
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c = 0;
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a = 0;
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}
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SamplerState::Sampled
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},
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)
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.await;
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}
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