Sensor Sleep Supprt an some Optimisations for the SPS30

include/debug.h

@@ -8,9 +8,11 @@ DebugUtils.h - Simple debugging utilities.
 #ifdef DEBUG
   #define DEBUG_PRINT(...) Serial.print(__VA_ARGS__); Serial.flush();
   #define DEBUG_PRINTLN(...) Serial.println(__VA_ARGS__); Serial.flush();
+  #define DEBUG_PRINTARR(...) for (uint8_t i=0; i<(sizeof(__VA_ARGS__)/sizeof(__VA_ARGS__[0])); i++) { Serial.print(__VA_ARGS__[i], HEX); Serial.print(" ");}; Serial.flush();
 #else
   #define DEBUG_PRINT(...)
   #define DEBUG_PRINTLN(...)
+  #define DEBUG_PRINTARR(...)
 #endif
 
 #endif

lib/SPS30/SPS30.cpp

@@ -27,69 +27,90 @@
 #include <Arduino.h>
 #include "SPS30.h"
 
-SPS30::SPS30() {
+// Read Measurements from Sensor and put them into the Paylaod
-}
-
-
 uint8_t SPS30::getSensorData(char *payload, uint8_t startbyte) {
+  // Buffer to hold the raw I2C Return
   uint8_t  data[30]; 
-  for (uint8_t i = 0; i < 30; i++)
+  // Array with calculated Values.
-    data[i] = 0xFF;
+  // Predefined with 0xEEEE to recognize Read Errors in the Payload
+  uint16_t values[5] = {0xEEEE, 0xEEEE, 0xEEEE, 0xEEEE, 0xEEEE};
 
-  uint16_t massPM1, massPM25, massPM4, massPM10, typPM;
+  // Wakeup Sensor from Sleep
+  DEBUG_PRINTLN("SPS30::getSensorData - Wake Up Sensor");
+  Wire.beginTransmission(SPS30_I2C_ADDRESS);
+  Wire.endTransmission();
+  delay(50);
+  write(SPS30_WAKEUP);
+  delay(50);
 
   // Start Measuring, Integer Output
+  DEBUG_PRINTLN("SPS30::getSensorData - StartMeasurement");
   write(SPS30_START_MEASUREMENT, 0x0500);
-  // Wait for Stable Values (max 30s according to datasheet)
+  // Wait for Stable Values
-  delay(30000);
+  DEBUG_PRINTLN("SPS30::getSensorData - WaitForStabilize");
+  delay(SPS30_STABILIZE_TIME);
 
+  bool    dataok = false;
+  uint8_t tries = 5;
+
+  // Retry up to 5 times to get a Valid Measurement from the Sensor
+  while (!dataok && tries > 0) {
+    DEBUG_PRINT("SPS30::getSensorData - Reading Sensor Data, Try ");
+    DEBUG_PRINTLN(6-tries);
     if (hasData()) {
       write(SPS30_READ_MEASUREMENT);
       Wire.requestFrom(SPS30_I2C_ADDRESS, 30);
       if (Wire.available() != 0) { 
-      for (uint8_t i = 0; i < 30; i++)
-        data[i] = 0xFE;
-      
         Wire.readBytes(data, 30);
 
-      // DEBUG OUTPUT
+        DEBUG_PRINT("SPS30::getSensorData - I2C-Data: ");
-      DEBUG_PRINT("SPS30 I2C DATA: ")
+        DEBUG_PRINTARR(data);
-      for (uint8_t i = 0; i < 30; i++) {
-        DEBUG_PRINT("0x");
-        DEBUG_PRINT (data[i]);
-        DEBUG_PRINT(", ");
-      }
-        
         DEBUG_PRINTLN("");
 
-      // PM1.0
+        // Get Values for PM1.0, 2.5, 4 and 10 in Order
-      if (data[2] == calcCRC(data, 2))
+        dataok = true;
-        massPM1 = data[0] << 8 | data[1];
+        for (uint8_t i=0; i<4; i++)
+          if (data[(i*3)+2] == calcCRC(data+(i*3), 2)) {
+            values[i] = data[i*3] << 8 | data[(i*3)+1]; // Create uint16_t from Bytes
+          } else {
+            dataok = false; // Set false on Checksum Error
+          }
         
-      // PM2.5
+        // Get Typical Particle size
-      if (data[5] == calcCRC(data+3, 2))
+        if (data[29] == calcCRC(data+27, 2)) {
-        massPM25 = data[3] << 8 | data[4];
+          values[4] = data[27] << 8 | data[28]; // Create uint16_t from Bytes
+        } else {
+          dataok = false; // Set false on Checksum Error
+        }
         
-      // PM4
+        if (!dataok) {
-      if (data[8] == calcCRC(data+6, 2))
+          // If a Checksum error occured
-        massPM4 = data[6] << 8 | data[7];
+          DEBUG_PRINTLN("SPS30::getSensorData - CheckSum Error");
-      
+          tries--;
-      // PM10
+          delay(2000);
-      if (data[11] == calcCRC(data+9, 2))
+        }
-        massPM10 = data[9] << 8 | data[10];
+      } else {
-      
+        // No I2C Data Available
-      // Typical Size
+        DEBUG_PRINTLN("SPS30::getSensorData - Error, no I2C Data available");
-      if (data[29] == calcCRC(data+27, 2))
+        tries--;
-        typPM = data[27] << 8 | data[28];
+        delay(2000);
+      }
+    } else {
+      // No Data Ready from Sensor
+      DEBUG_PRINTLN("SPS30::getSensorData - Error, Sensor Data not Ready");
+      tries--;
+      delay(2000);
     }
   }
+  DEBUG_PRINTLN("SPS30::getSensorData - StopMeasurement");
   write(SPS30_STOP_MEASUREMENT);
+  delay(50);
+  DEBUG_PRINTLN("SPS30::getSensorData - SensorSleep");
+  write(SPS30_SLEEP);
   
-  uint16ToPayload(massPM1, payload, startbyte);
+  // Put the Values into the Payload Array
-  uint16ToPayload(massPM25, payload, startbyte+2);
+  for (uint8_t i=0; i<5; i++)
-  uint16ToPayload(massPM4, payload, startbyte+4);
+    uint16ToPayload(values[i], payload, startbyte+(i*2));
-  uint16ToPayload(massPM10, payload, startbyte+6);
-  uint16ToPayload(typPM, payload, startbyte+8);
 }
 
 // Check if Sensor has Data
@@ -114,6 +135,7 @@ uint16_t SPS30::readReg(uint16_t regAddr) {
   return(0);
 }
 
+// Write a 16 Bit Command without Parameters
 bool SPS30::write(uint16_t cmd) {
   Wire.beginTransmission(SPS30_I2C_ADDRESS);
   Wire.write(cmd >> 8);
@@ -123,6 +145,7 @@ bool SPS30::write(uint16_t cmd) {
   return(true);
 }
 
+// Write a 16Bit Command with 16Bit Parameters
 bool SPS30::write(uint16_t cmd, uint16_t arg){
   uint8_t crcdata[2];
   crcdata[0] = arg >> 8;

lib/SPS30/SPS30.h

@@ -33,6 +33,7 @@
 
 // I2C Address
 #define SPS30_I2C_ADDRESS    0x69
+#define SPS30_STABILIZE_TIME 30000
 
 // I2C Commands and Registers
 #define SPS30_START_MEASUREMENT   0x0010
@@ -44,6 +45,8 @@
 #define SPS30_READ_ARTICLE_CODE   0xD025
 #define SPS30_READ_SERIAL_NUMBER  0xD033
 #define SPS30_DEVICE_RESET        0xD304
+#define SPS30_SLEEP               0x1001
+#define SPS30_WAKEUP              0x1103
 
 class SPS30 : public AttSensor {
   private:
@@ -54,11 +57,11 @@ class SPS30 : public AttSensor {
     bool write(uint16_t cmd, uint16_t arg);
   
   public:
-    SPS30();
+    SPS30() {};
-    uint8_t getSensorData(char *payload, uint8_t startbyte);
+    uint8_t getSensorData(char *payload, uint8_t startbyte) override;
-    void calibrate(void) {};
+    void calibrate(void) override {};
-    void initialize(void) {};
+    void initialize(void) override {} ;
-    uint8_t numBytes(void) { return 10; };
+    uint8_t numBytes(void) override { return 10; };
 };
 
 #endif