rp: Add multichannel ADC

1 files changed, 54 insertions, 0 deletions

diff --git a/examples/rp/src/bin/adc_dma.rs b/examples/rp/src/bin/adc_dma.rs
new file mode 100644
index 000000000..f755cf5bf
--- /dev/null
+++ b/examples/rp/src/bin/adc_dma.rs
@@ -0,0 +1,54 @@
+//! This example shows how to use the RP2040 ADC with DMA, both single- and multichannel reads.
+//! For multichannel, the samples are interleaved in the buffer:
+//! `[ch1, ch2, ch3, ch4, ch1, ch2, ch3, ch4, ...]`
+#![no_std]
+#![no_main]
+
+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, Ticker};
+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());
+    info!("Here we go!");
+
+    let mut adc = Adc::new(p.ADC, Irqs, Config::default());
+    let mut dma = p.DMA_CH0;
+    let mut pin = Channel::new_pin(p.PIN_26, Pull::Up);
+    let mut pins = [
+        Channel::new_pin(p.PIN_27, Pull::Down),
+        Channel::new_pin(p.PIN_28, Pull::None),
+        Channel::new_pin(p.PIN_29, Pull::Up),
+        Channel::new_temp_sensor(p.ADC_TEMP_SENSOR),
+    ];
+
+    const BLOCK_SIZE: usize = 100;
+    const NUM_CHANNELS: usize = 4;
+    let mut ticker = Ticker::every(Duration::from_secs(1));
+    loop {
+        // Read 100 samples from a single channel
+        let mut buf = [0_u16; BLOCK_SIZE];
+        let div = 479; // 100kHz sample rate (48Mhz / 100kHz - 1)
+        adc.read_many(&mut pin, &mut buf, div, &mut dma).await.unwrap();
+        info!("single: {:?} ...etc", buf[..8]);
+
+        // Read 100 samples from 4 channels interleaved
+        let mut buf = [0_u16; { BLOCK_SIZE * NUM_CHANNELS }];
+        let div = 119; // 100kHz sample rate (48Mhz / 100kHz * 4ch - 1)
+        adc.read_many_multichannel(&mut pins, &mut buf, div, &mut dma)
+            .await
+            .unwrap();
+        info!("multi:  {:?} ...etc", buf[..NUM_CHANNELS * 2]);
+
+        ticker.next().await;
+    }
+}