Merge pull request #13 from brentru/work-with-ikea-sensor

Add compatability and auto-detection for the Cubic PM1006 air quality sensor

Adafruit_PM25AQI.cpp

@@ -9,6 +9,8 @@
  * Arduino platform.  It is designed specifically to work with the
  * Adafruit PM2.5 Air quality sensors: http://www.adafruit.com/products/4632
  *
+ * This library also works with the Cubic PM1006 UART Air Quality Sensor.
+ *
  * These sensors use I2C or UART to communicate.
  *
  * Adafruit invests time and resources providing this open source code,
@@ -18,6 +20,8 @@
  *
  * @section author Author
  * Written by Ladyada for Adafruit Industries.
+ * Modified by Brent Rubell for Adafruit Industries for use with Cubic PM1006
+ * Air Quality Sensor.
  *
  * @section license License
  * BSD license, all text here must be included in any redistribution.
@@ -69,7 +73,10 @@ bool Adafruit_PM25AQI::begin_UART(Stream *theSerial) {
  */
 bool Adafruit_PM25AQI::read(PM25_AQI_Data *data) {
   uint8_t buffer[32];
+  size_t bufLen = sizeof(buffer);
   uint16_t sum = 0;
+  uint8_t csum = 0;
+  bool is_pm1006 = false;
 
   if (!data) {
     return false;
@@ -83,48 +90,81 @@ bool Adafruit_PM25AQI::read(PM25_AQI_Data *data) {
     if (!serial_dev->available()) {
       return false;
     }
+
     int skipped = 0;
-    while ((skipped < 32) && (serial_dev->peek() != 0x42)) {
+    while ((skipped < 32) && (serial_dev->peek() != 0x42) &&
+           (serial_dev->peek() != 0x16)) {
       serial_dev->read();
       skipped++;
       if (!serial_dev->available()) {
         return false;
       }
     }
-    if (serial_dev->peek() != 0x42) {
+
+    // Check for the start character in the stream for both sensors
+    if ((serial_dev->peek() != 0x42) && (serial_dev->peek() != 0x16)) {
       serial_dev->read();
       return false;
     }
-    // Now read all 32 bytes
-    if (serial_dev->available() < 32) {
+
+    // Are we using the Cubic PM1006 sensor?
+    if (serial_dev->peek() == 0x16) {
+      is_pm1006 = true; // Set flag to indicate we are using the PM1006
+      bufLen =
+          20; // Reduce buffer read length to 20 bytes. Last 12 bytes ignored.
+    }
+
+    // Are there enough bytes to read from?
+    if (serial_dev->available() < bufLen) {
       return false;
     }
-    serial_dev->readBytes(buffer, 32);
+
+    // Read all available bytes from the serial stream
+    serial_dev->readBytes(buffer, bufLen);
   } else {
     return false;
   }
 
-  // Check that start byte is correct!
-  if (buffer[0] != 0x42) {
+  // Validate start byte is correct if using Adafruit PM sensors
+  if ((!is_pm1006 && buffer[0] != 0x42)) {
     return false;
   }
 
-  // get checksum ready
-  for (uint8_t i = 0; i < 30; i++) {
-    sum += buffer[i];
+  // Validate start header is correct if using Cubic PM1006 sensor
+  if (is_pm1006 &&
+      (buffer[0] != 0x16 || buffer[1] != 0x11 || buffer[2] != 0x0B)) {
+    return false;
   }
 
-  // The data comes in endian'd, this solves it so it works on all platforms
-  uint16_t buffer_u16[15];
-  for (uint8_t i = 0; i < 15; i++) {
-    buffer_u16[i] = buffer[2 + i * 2 + 1];
-    buffer_u16[i] += (buffer[2 + i * 2] << 8);
+  // Calculate checksum
+  if (!is_pm1006) {
+    for (uint8_t i = 0; i < 30; i++) {
+      sum += buffer[i];
+    }
+  } else {
+    for (uint8_t i = 0; i < bufLen; i++) {
+      csum += buffer[i];
+    }
   }
 
-  // put it into a nice struct :)
-  memcpy((void *)data, (void *)buffer_u16, 30);
+  // Since header and checksum are OK, parse data from the buffer
+  if (!is_pm1006) {
+    // The data comes in endian'd, this solves it so it works on all platforms
+    uint16_t buffer_u16[15];
+    for (uint8_t i = 0; i < 15; i++) {
+      buffer_u16[i] = buffer[2 + i * 2 + 1];
+      buffer_u16[i] += (buffer[2 + i * 2] << 8);
+    }
+    // put it into a nice struct :)
+    memcpy((void *)data, (void *)buffer_u16, 30);
+  } else {
+    // Cubic PM1006 sensor only produces a pm25_env reading
+    data->pm25_env = (buffer[5] << 8) | buffer[6];
+    data->checksum = sum;
+  }
 
-  if (sum != data->checksum) {
+  // Validate checksum
+  if ((is_pm1006 && csum != 0) || (!is_pm1006 && sum != data->checksum)) {
     return false;
   }
 

README.md

@@ -5,6 +5,8 @@ Tested and works great with the Adafruit PM2.5 Air Quality Sensor and Breadboard
 
 [<img src="https://cdn-shop.adafruit.com/1200x900/3686-10.jpg" width="500px">](https://www.adafruit.com/products/3686)
 
+This library also works with the Cubic PM1006 air quality sensor present on the [IKEA VINDSTYRKA](https://www.ikea.com/us/en/p/vindriktning-air-quality-sensor-60515911/). Please use the `pm1006_test.ino` sketch to use this sensor.
+
 Adafruit invests time and resources providing this open source code, please support Adafruit and open-source hardware by purchasing products from Adafruit!
 
 # Installation

examples/PM1006_test/.uno.test.skip

@@ -0,0 +1 @@
+

examples/PM1006_test/PM1006_test.ino

@@ -0,0 +1,71 @@
+/****************************************************************************************
+  Test sketch for using the Adafruit_PM25AQI library with
+  the Cubic PM1006 UART Air Quality Sensor.
+
+  This sensor is present on the VINDRIKTNING Air Quality sensor, sold by IKEA.
+
+  Check out the guide below for the wiring diagram:
+  https://learn.adafruit.com/ikea-vindriktning-hack-with-qt-py-esp32-s3-and-adafruit-io
+
+
+  Adafruit invests time and resources providing this open source code,
+  please support Adafruit and open-source hardware by purchasing
+  products from Adafruit!
+
+  Written by Limor Fried/Ladyada for Adafruit Industries.
+  Modified by Brent Rubell for Adafruit Industries
+  MIT license, all text above must be included in any redistribution
+ *****************************************************************************************/
+#include "Adafruit_PM25AQI.h"
+
+// For UNO and others (without hardware serial) we must use software serial...
+// pin #2 is IN from sensor (TX pin on sensor), leave pin #3 disconnected
+// comment these two lines if using hardware serial
+//#include <SoftwareSerial.h>
+//SoftwareSerial pmSerial(2, 3);
+
+Adafruit_PM25AQI aqi = Adafruit_PM25AQI();
+
+void setup() {
+  // Wait for serial monitor to open
+  Serial.begin(115200);
+  while (!Serial) delay(10);
+
+  Serial.println("Cubic PM1006 Air Quality Sensor");
+
+  // Wait one second for sensor to boot up!
+  delay(1000);
+
+  // If using serial, initialize it and set baudrate before starting!
+  Serial1.begin(9600);
+  // Uncomment the following for use with software serial
+  //pmSerial.begin(9600);
+
+  if (! aqi.begin_UART(&Serial1)) { // connect to the sensor over hardware serial
+  //if (! aqi.begin_UART(&pmSerial)) { // connect to the sensor over software serial 
+    Serial.println("Could not find Cubic PM1006 sensor!");
+    while (1) delay(10);
+  }
+
+  Serial.println("Cubic PM1006 found!");
+}
+
+void loop() {
+  PM25_AQI_Data data;
+
+  if (! aqi.read(&data)) {
+    Serial.println("Could not read from PM1006 sensor");
+    delay(5000);  // Sample every 5 seconds
+    return;
+  }
+  Serial.println("AQI reading success");
+
+  Serial.println();
+  Serial.println(F("---------------------------------------"));
+  Serial.println(F("Concentration Units (environmental)"));
+  Serial.println(F("---------------------------------------"));
+  Serial.print(F("PM 1.0: ")); Serial.print(data.pm25_env);
+  Serial.println(F("---------------------------------------"));
+
+  delay(20000); // Wait 20 seconds and get another reading from the IKEA Vindriktning
+}

library.properties

@@ -1,5 +1,5 @@
 name=Adafruit PM25 AQI Sensor
-version=1.0.8
+version=1.1.0
 author=Adafruit
 maintainer=Adafruit <[email protected]>
 sentence=This is an Arduino library for the Adafruit PM2.5 Air Quality Sensor