From c2742cde3d034b2af9bbcee90765338ee094e6cc Mon Sep 17 00:00:00 2001
From: "Matthias P. Braendli" <matthias.braendli@mpb.li>
Date: Wed, 3 Jan 2024 21:57:27 +0100
Subject: Add src/radio and freq config

---
 src/radio.rs | 161 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 161 insertions(+)
 create mode 100644 src/radio.rs

(limited to 'src/radio.rs')

diff --git a/src/radio.rs b/src/radio.rs
new file mode 100644
index 0000000..77f7c0f
--- /dev/null
+++ b/src/radio.rs
@@ -0,0 +1,161 @@
+use anyhow::{anyhow, bail, Context};
+use rand::{thread_rng, Rng};
+use rf4463::{config::RADIO_CONFIG_CATS, Rf4463};
+use rppal::{
+    gpio::{Gpio, OutputPin},
+    hal::Delay,
+    spi::{Bus, Mode, SlaveSelect, Spi},
+};
+use std::{
+    sync::Arc,
+    time::{Duration, Instant},
+};
+use tokio::sync::{
+    mpsc::{error::TryRecvError, Receiver, Sender},
+    Mutex,
+};
+
+pub const MAX_PACKET_LEN: usize = 8191;
+
+pub struct RadioManager {
+    radio: Rf4463<Spi, OutputPin, OutputPin, Delay>,
+
+    tx: Sender<(Vec<u8>, f64)>,
+    rx: Receiver<Vec<u8>>,
+    rx_buf: [u8; MAX_PACKET_LEN],
+    temperature: Arc<Mutex<f32>>,
+}
+
+impl RadioManager {
+    pub fn new(tx: Sender<(Vec<u8>, f64)>, rx: Receiver<Vec<u8>>) -> anyhow::Result<Self> {
+        let spi = Spi::new(Bus::Spi0, SlaveSelect::Ss0, 1_000_000, Mode::Mode0)?;
+        let gpio = Gpio::new()?;
+        let sdn = gpio.get(22)?.into_output();
+        let cs = gpio.get(24)?.into_output();
+
+        let delay = Delay::new();
+
+        let mut radio = Rf4463::new(spi, sdn, cs, delay, &mut RADIO_CONFIG_CATS.clone())
+            .map_err(|e| anyhow!("{e:?}"))?;
+        radio.set_channel(20);
+
+        let rx_buf = [0; MAX_PACKET_LEN];
+        let temperature = Arc::new(Mutex::new(radio.get_temp()?));
+
+        Ok(Self {
+            radio,
+            tx,
+            rx,
+            rx_buf,
+            temperature,
+        })
+    }
+
+    pub fn set_channel(&mut self, channel: u8) {
+        self.radio.set_channel(channel);
+    }
+
+    pub fn temperature_mutex(&self) -> Arc<Mutex<f32>> {
+        self.temperature.clone()
+    }
+
+    pub async fn process_forever(&mut self) -> anyhow::Result<()> {
+        loop {
+            self.tick().await?;
+
+            *self.temperature.lock().await = self.radio.get_temp()?;
+
+            match self.rx.try_recv() {
+                Ok(pkt) => {
+                    self.tx(&pkt).await?;
+                }
+                Err(TryRecvError::Empty) => {}
+                Err(TryRecvError::Disconnected) => {
+                    bail!("RX channel disconnected")
+                }
+            }
+
+            tokio::time::sleep(Duration::from_millis(25)).await;
+        }
+    }
+
+    async fn tick(&mut self) -> anyhow::Result<()> {
+        if self.radio.is_idle() {
+            self.radio
+                .start_rx(None, false)
+                .map_err(|e| anyhow!("{e}"))?;
+
+            tokio::time::sleep(Duration::from_millis(25)).await;
+        }
+
+        self.radio
+            .interrupt(Some(&mut self.rx_buf), None)
+            .map_err(|e| anyhow!("{e:?}"))?;
+
+        if let Some(data) = self
+            .radio
+            .finish_rx(&mut self.rx_buf)
+            .map_err(|e| anyhow!("{e}"))?
+        {
+            self.radio
+                .start_rx(None, false)
+                .map_err(|e| anyhow!("{e}"))?;
+
+            self.tx
+                .send((data.data().to_vec(), data.rssi()))
+                .await
+                .ok()
+                .context("TX channel died")?;
+        }
+
+        Ok(())
+    }
+
+    async fn tx(&mut self, data: &[u8]) -> anyhow::Result<()> {
+        // ensures we don't tx over a packet,
+        // and adds some random delay so that every node
+        // if offset slightly
+        self.tx_delay().await?;
+
+        self.radio.start_tx(data).map_err(|e| anyhow!("{e:?}"))?;
+
+        const TIMEOUT: Duration = Duration::from_secs(10);
+        let start_time = Instant::now();
+        while !self.radio.is_idle() {
+            self.radio
+                .interrupt(None, Some(data))
+                .map_err(|e| anyhow!("{e:?}"))?;
+
+            if start_time + TIMEOUT < Instant::now() {
+                bail!("Timeout while transmitting");
+            }
+
+            tokio::time::sleep(Duration::from_millis(25)).await;
+        }
+
+        Ok(())
+    }
+
+    async fn tx_delay(&mut self) -> anyhow::Result<()> {
+        loop {
+            let delay_ms = thread_rng().gen_range(0..50);
+
+            // since delay_ms < 100 we can safely sleep without calling tick
+            tokio::time::sleep(Duration::from_millis(delay_ms)).await;
+
+            let mut rx = false;
+
+            while self.radio.is_busy_rxing()? {
+                rx = true;
+                self.tick().await?;
+
+                tokio::time::sleep(Duration::from_millis(25)).await;
+            }
+
+            if !rx {
+                // didn't rx a packet, so we're safe to leave
+                break Ok(());
+            }
+        }
+    }
+}
-- 
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