From d87215bebd8aaaf99d51c2853f2c0af33d6a7887 Mon Sep 17 00:00:00 2001
From: Joseph Ferano <joseph@ferano.io>
Date: Wed, 11 Jun 2025 13:26:29 +0700
Subject: [PATCH] =?UTF-8?q?=F0=9F=93=9F=20pmme-device:=20PM2.5=20is=20now?=
 =?UTF-8?q?=20being=20read=20and=20written=20to=20an=20ArcMutex?=
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---
 pmme-device/rust-version/src/main.rs | 78 +++++++++++++++++++++++-----
 1 file changed, 66 insertions(+), 12 deletions(-)

diff --git a/pmme-device/rust-version/src/main.rs b/pmme-device/rust-version/src/main.rs
index f192b6e..eb430dc 100644
--- a/pmme-device/rust-version/src/main.rs
+++ b/pmme-device/rust-version/src/main.rs
@@ -22,9 +22,31 @@ use ssd1306::{I2CDisplayInterface, Ssd1306, size::*, rotation::*};
 use ssd1306::mode::DisplayConfig;
 
 use std::thread;
-use log::info;
+use std::sync::{Arc, Mutex};
+use log::{info, warn};
 
-fn oled_task(i2c: I2cDriver) -> Result<()> {
+#[derive(Debug, Clone, Default)]
+pub struct Pms7003Data {
+    // PM concentrations (CF=1, standard particle) in μg/m³
+    pub pm1_0_cf1: u16,
+    pub pm2_5_cf1: u16,
+    pub pm10_cf1: u16,
+
+    // PM concentrations (atmospheric environment) in μg/m³
+    pub pm1_0_atm: u16,
+    pub pm2_5_atm: u16,
+    pub pm10_atm: u16,
+
+    // Particle counts (particles per 0.1L air)
+    pub particles_0_3um: u16,
+    pub particles_0_5um: u16,
+    pub particles_1_0um: u16,
+    pub particles_2_5um: u16,
+    pub particles_5_0um: u16,
+    pub particles_10um: u16,
+}
+
+fn oled_task(pm_data: Arc<Mutex<Pms7003Data>>, i2c: I2cDriver) -> Result<()> {
     info!("Staring OLED Task");
 
     let interface = I2CDisplayInterface::new(i2c);
@@ -39,11 +61,12 @@ fn oled_task(i2c: I2cDriver) -> Result<()> {
     im.draw(&mut display).unwrap();
     display.flush().map_err(|e| anyhow!("Could not flush display! {:?}", e))?;
 
-    FreeRtos::delay_ms(3000);
+    FreeRtos::delay_ms(2000);
     loop {
+        let current_pm_data = pm_data.lock().unwrap().clone();
         display.clear(BinaryColor::Off).map_err(|e| anyhow!("Could not clear display! {:?}", e))?;
         Text::new(
-            "PM 2.5: 4",
+            &format!("PM 2.5: {}", current_pm_data.pm2_5_atm),
             Point::new(20, 40),
             MonoTextStyle::new(&FONT_10X20, BinaryColor::On),
         ).draw(&mut display).map_err(|e| anyhow!("Could not draw text! {:?}", e))?;
@@ -52,6 +75,32 @@ fn oled_task(i2c: I2cDriver) -> Result<()> {
     }
 }
 
+// u16::from_be_bytes is too verbose
+fn get_u16(buf: &[u8]) -> u16 { ((buf[0] as u16) << 8) | buf[1] as u16 }
+
+fn read_pm_data(buf: &[u8; 32]) -> Option<Pms7003Data> {
+    let checksum: u16 = buf.iter().take(29).copied().map(u16::from).sum();
+    let csum_target = get_u16(&buf[30..32]);
+    if checksum != csum_target {
+        warn!("Checksum from PMS7003 READ does not match, skipping read");
+        return None
+    }
+    Some(Pms7003Data {
+        pm1_0_cf1:       get_u16(&buf[ 4..6 ]),
+        pm2_5_cf1:       get_u16(&buf[ 6..8 ]),
+        pm10_cf1:        get_u16(&buf[ 8..10]),
+        pm1_0_atm:       get_u16(&buf[10..12]),
+        pm2_5_atm:       get_u16(&buf[12..14]),
+        pm10_atm:        get_u16(&buf[14..16]),
+        particles_0_3um: get_u16(&buf[16..18]),
+        particles_0_5um: get_u16(&buf[18..20]),
+        particles_1_0um: get_u16(&buf[20..22]),
+        particles_2_5um: get_u16(&buf[22..24]),
+        particles_5_0um: get_u16(&buf[24..26]),
+        particles_10um:  get_u16(&buf[26..28]),
+    })
+}
+
 fn send_pms7003_command(uart: &UartDriver, cmd: u8, datah: u8, datal: u8) -> Result<()> {
     let mut command = [0x42u8, 0x4D, cmd, datah, datal, 0, 0];
 
@@ -66,23 +115,23 @@ fn send_pms7003_command(uart: &UartDriver, cmd: u8, datah: u8, datal: u8) -> Res
     Ok(())
 }
 
-fn pm_sensor_task(uart: &UartDriver) -> Result<()> {
+fn pm_sensor_task(pm_data: Arc<Mutex<Pms7003Data>>, uart: &UartDriver) -> Result<()> {
     info!("Staring UART PM Sensor Task");
 
     send_pms7003_command(uart, 0xE1, 0x00, 0x00)?;
 
-    let mut buf = [0_u8; 32];
     loop {
         send_pms7003_command(uart, 0xE2, 0x00, 0x00)?;
 
+        let mut buf = [0_u8; 32];
         let len = uart.read(&mut buf, BLOCK)?;
         if len > 0 {
-            info!("Read some bytes! {}", len);
-            for i in 0..len {
-                info!("0x{:02x}", buf[i]);
+            if let Some(data) = read_pm_data(&buf) {
+                let mut pm_data = pm_data.lock().unwrap();
+                *pm_data = data;
             }
         } else {
-            info!("No bytes read");
+            // info!("No bytes read");
         }
         uart.clear_rx()?;
         FreeRtos::delay_ms(5000);
@@ -120,14 +169,19 @@ fn main() -> Result<()> {
         &config,
     )?;
 
+    let pm_data = Arc::new(Mutex::new(Pms7003Data::default()));
+
+    let pm_data1 = Arc::clone(&pm_data);
+    let pm_data2 = Arc::clone(&pm_data);
+
     let handles = vec! [
         thread::spawn(move || {
-            if let Err(e) = oled_task(i2c) {
+            if let Err(e) = oled_task(pm_data1, i2c) {
                 log::error!("OLED Task Error: {:?}", e);
             }
         }),
         thread::spawn(move || {
-            if let Err(e) = pm_sensor_task(&uart) {
+            if let Err(e) = pm_sensor_task(pm_data2, &uart) {
                 log::error!("PM Sensor Task Error: {:?}", e);
             }
         }),