include/attsensor.h

@@ -0,0 +1,44 @@
+/*
+  attsensor.h - Define the Base Sensor Interface Class
+  Copyright (c) 2020-2021, Stefan Brand
+  All rights reserved.
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+  1. Redistributions of source code must retain the above copyright notice, this
+     list of conditions and the following disclaimer.
+  2. Redistributions in binary form must reproduce the above copyright notice,
+     this list of conditions and the following disclaimer in the documentation
+     and/or other materials provided with the distribution.
+  3. Neither the name of the copyright holder nor the names of its
+     contributors may be used to endorse or promote products derived from
+     this software without specific prior written permission.
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+#ifndef ATTSENSOR_H
+#define ATTSENSOR_H
+
+#include <inttypes.h>
+
+class AttSensor  {
+  public:
+    // Put the Data into the Payload Array starting at <startbyte>
+    // Return the next startbyte when done
+    virtual uint8_t getSensorData(char *payload, uint8_t startbyte) = 0;
+    
+    // Called in Setup, Do any Necessary Initialization
+    virtual void initialize(void) = 0;
+
+    // Return the number of Bytes added to the Payload
+    virtual uint8_t numBytes(void) = 0;
+};
+
+#endif

lib/BME280/BME280.cpp

@@ -1,5 +1,4 @@
 #include <Arduino.h>
-#include <stdint.h>
 #include <Wire.h>
 #include "BME280.h"
 
@@ -78,10 +77,10 @@ int32_t BME280::compensate_h(int32_t adc_H)
   return (uint32_t)((v_x1_u32r>>12)/10);
 }
 
-void BME280::getSensorData(lora_data &loradata) {
+uint8_t BME280::getSensorData(char *payload, uint8_t startbyte) {
 
 	int32_t UP, UT, UH;
-  int32_t rawP, rawT;
+  int32_t rawP, rawT, value;
 
   // Trigger Measurement
  	// Set Sensor Config
@@ -105,10 +104,28 @@ void BME280::getSensorData(lora_data &loradata) {
 	// Read Humidity
   UH = read16(0xFD);
 
-	// Compensate Values and Return
+	
-	loradata.temperature = compensate_t(UT);
+  // Temperature
-  loradata.pressure    = compensate_p(UP);
+	value                = compensate_t(UT);
-  loradata.humidity    = compensate_h(UH);
+  payload[startbyte]   = (value) & 0XFF;
+  payload[startbyte+1] = (value >> 8) & 0XFF;
+  payload[startbyte+2] = (value >> 16) & 0XFF;
+  payload[startbyte+3] = (value >> 24) & 0XFF;
+
+  // Humidity
+  value                = compensate_h(UH);
+  payload[startbyte+4] = (value) & 0XFF;
+  payload[startbyte+5] = (value >> 8) & 0XFF;
+  payload[startbyte+6] = (value >> 16) & 0XFF;
+  payload[startbyte+7] = (value >> 24) & 0XFF;
+
+  // Pressure
+  value                 = compensate_p(UP);
+  payload[startbyte+8]  = (value) & 0XFF;
+  payload[startbyte+9]  = (value >> 8) & 0XFF;
+  payload[startbyte+10] = (value >> 16) & 0XFF;
+  payload[startbyte+11] = (value >> 24) & 0XFF;
+  return startbyte+12;
 }
 
 uint8_t BME280::read8(uint8_t addr) {

lib/BME280/BME280.h

@@ -1,19 +1,11 @@
 #ifndef BME280_H
 #define BME280_H
 
-#include <stdint.h>
+#include "../../include/attsensor.h"
 
 #define BME280_I2CADDR 0x76
 
-struct lora_data {
+class BME280 : public AttSensor {
-  uint8_t bat;
-  int32_t temperature;
-  int32_t humidity;
-  int32_t pressure;
-} __attribute__ ((packed));
-
-class BME280
-{
 private:
   // Variables for Calibration Values
   uint8_t  dig_H1, dig_H3;
@@ -36,13 +28,12 @@ private:
   int16_t  readS16(uint8_t addr);
   int16_t  readS16_LE(uint8_t addr);
   void     write8(uint8_t addr, uint8_t data);
+  void     getCalData(void);
 
 public:
   BME280(void);
-
+  uint8_t getSensorData(char *payload, uint8_t startbyte);
-  // Get Calibration Data from Sensor
+  void initialize(void) {getCalData();};
-  void getCalData(void);
+  uint8_t numBytes(void) {return 12;};
-  // Read Pressure From Sensor
-  void getSensorData(lora_data &loradata);
 };
 #endif

lib/MHZ19C/MHZ19C.cpp

@@ -41,19 +41,23 @@ void MHZ19C::initialize(void) {
   #endif
 }
 
-void MHZ19C::getSensorData(lora_data &loradata) {
+uint8_t MHZ19C::getSensorData(char * payload, uint8_t startbyte) {
     write(MHZ19C_CMD_GET_PPM, 0x00);
     delay(50);
     uint8_t readBytes = read();
     
-    loradata.ppm = 0;
+    payload[startbyte]   = 0x00;
+    payload[startbyte+1] = 0x00;
     if (readBytes > 0) {
         switch(buffer[1]) {
             case 0x86:
-                loradata.ppm = (buffer[2]*256) + buffer[3];
+                  int16_t value = (buffer[2]*256) + buffer[3];
+                  payload[startbyte]   = (value) & 0xFF;
+                  payload[startbyte+1] = (value >> 8) & 0xFF;
                 break;
         }
     }
+    return startbyte+2;
 }
 
 // Turn Self Calibration Routine On or Off

lib/MHZ19C/MHZ19C.h

@@ -27,11 +27,7 @@
 #ifndef MHZ19C_H
 #define MHZ19C_H
 
-// Data Structure for the LoRa Packet
+#include "../../include/attsensor.h"
-struct lora_data {
-  uint8_t bat;
-  int16_t ppm;
-} __attribute__ ((packed));
 
 #define MHZ19C_READ_TIMEOUT 500  // Timeout for Serial Communication
 #define MHZ19C_SER_BUF_LEN  9    // Length of the Internal Serial Message Buffer
@@ -39,7 +35,7 @@ struct lora_data {
 #define MHZ19C_CMD_SET_AUTOCAL 0x79  // Turn Self Calibration on/off
 #define MHZ19C_CMD_GET_PPM     0x86  // Get Current PPM Reading
 
-class MHZ19C {
+class MHZ19C : public AttSensor {
   private:
     uint8_t buffer[MHZ19C_SER_BUF_LEN];
 
@@ -51,8 +47,9 @@ class MHZ19C {
 
   public:
     MHZ19C(void);
-    void MHZ19C::initialize(void);
+    void initialize(void);
-    void getSensorData(lora_data &loradata);
+    uint8_t numBytes(void) {return 2;};
+    uint8_t getSensorData(char *payload, uint8_t startbyte);
     void setSelfCalibration(bool state);
 };
 

lib/SENSAIRS8/SENSAIRS8.cpp

@@ -33,7 +33,7 @@ SENSAIRS8::SENSAIRS8(void) {
     Serial.setTimeout(READ_TIMEOUT);
 }
 
-void SENSAIRS8::getSensorData(lora_data &loradata) {
+uint8_t SENSAIRS8::getSensorData(char *payload, uint8_t startbyte) {
   uint8_t _cmd[7] = {0xFE, 0x44, 0x00, 0x08, 0x02, 0x9F, 0x25};
   while (Serial.available() > 0) Serial.read();
     Serial.write(_cmd, 7);
@@ -41,9 +41,14 @@ void SENSAIRS8::getSensorData(lora_data &loradata) {
   delay(1000);
   uint8_t readBytes = read();
   
+  payload[startbyte]   = 0x00;
+  payload[startbyte+1] = 0x00;
   if (readBytes > 0) {
-    loradata.ppm = (buffer[3]*256) + buffer[4];
+    int16_t value =  (buffer[3]*256) + buffer[4];
+    payload[startbyte]   = (value) & 0xFF;
+    payload[startbyte+1] = (value >> 8) & 0xFF;
   }
+  return startbyte+2;
 }
 
 // Read a Sensor Response

lib/SENSAIRS8/SENSAIRS8.h

@@ -27,16 +27,12 @@
 #ifndef SENSAIRS8_H
 #define SENSAIRS8_H
 
-// Data Structure for the LoRa Packet
+#include "../../include/attsensor.h"
-struct lora_data {
-  uint8_t bat;
-  int16_t ppm;
-} __attribute__ ((packed));
 
 #define READ_TIMEOUT 500  // Timeout for Serial Communication
 #define SER_BUF_LEN  7   // Length of the Internal Serial Message Buffer
 
-class SENSAIRS8 {
+class SENSAIRS8 : public AttSensor {
   private:
     uint8_t buffer[SER_BUF_LEN];
 
@@ -46,7 +42,9 @@ class SENSAIRS8 {
 
   public:
     SENSAIRS8(void);
-    void getSensorData(lora_data &loradata);
+    uint8_t getSensorData(char *payload, uint8_t startbyte);
+    void initialize(void) {};
+    uint8_t numBytes(void) {return 2;};
 };
 
 #endif

lib/SG112A/SG112A.cpp

@@ -33,18 +33,24 @@ SG112A::SG112A(void) {
     Serial.setTimeout(READ_TIMEOUT);
 }
 
-void SG112A::getSensorData(lora_data &loradata) {
+
+uint8_t SG112A::getSensorData(char *payload, uint8_t startbyte) {
     write(CMD_GET_PPM);
     delay(50);
     uint8_t readBytes = read();
     
+    payload[startbyte]   = 0x00;
+    payload[startbyte+1] = 0x00;
     if (readBytes > 0) {
         switch(buffer[2]) {
             case 0x15:
-                loradata.ppm = (buffer[5]*256) + buffer[4];
+                uint16_t value = (buffer[5]*256) + buffer[4];
+                payload[startbyte]   = (value) & 0xFF;
+                payload[startbyte+1] = (value >> 8) & 0xFF;
                 break;
         }
     }
+  return startbyte+2;
 }
 
 // Write a Command to the Sensor

lib/SG112A/SG112A.h

@@ -27,11 +27,7 @@
 #ifndef SG112A_H
 #define SG112A_H
 
-// Data Structure for the LoRa Packet
+#include "../../include/attsensor.h"
-struct lora_data {
-  uint8_t bat;
-  int16_t ppm;
-} __attribute__ ((packed));
 
 #define READ_TIMEOUT 500  // Timeout for Serial Communication
 #define SER_BUF_LEN  16   // Length of the Internal Serial Message Buffer
@@ -52,7 +48,9 @@ class SG112A {
 
   public:
     SG112A(void);
-    void getSensorData(lora_data &loradata);
+    uint8_t getSensorData(char *payload, uint8_t startbyte);
+    void initialize(void) {};
+    uint8_t numBytes(void) {return 2;};
 };
 
 #endif

lib/SHT21/SHT21.cpp

@@ -52,7 +52,20 @@ uint16_t SHT21::sensorRead(uint8_t command) {
     return result;
 }
 
-void SHT21::getSensorData(lora_data &loradata) {
+uint8_t SHT21::getSensorData(char *payload, uint8_t startbyte) {
-    loradata.temperature = (int32_t)((-46.85 + 175.72 / 65536.0 * (float)(sensorRead(SHT21_TEMPHOLD)))*100);
+  // Temperature
-    loradata.humidity    = (int32_t)((-6.0 + 125.0 / 65536.0 * (float)(sensorRead(SHT21_HUMIHOLD)))*100);
+  int32_t value = (int32_t)((-46.85 + 175.72 / 65536.0 * (float)(sensorRead(SHT21_TEMPHOLD)))*100);
+  payload[startbyte]   = (value) & 0XFF;
+  payload[startbyte+1] = (value >> 8) & 0XFF;
+  payload[startbyte+2] = (value >> 16) & 0XFF;
+  payload[startbyte+3] = (value >> 24) & 0XFF;
+
+  // Humidity
+  value = (int32_t)((-6.0 + 125.0 / 65536.0 * (float)(sensorRead(SHT21_HUMIHOLD)))*100);
+  payload[startbyte+4]  = (value) & 0XFF;
+  payload[startbyte+5]  = (value >> 8) & 0XFF;
+  payload[startbyte+6] = (value >> 16) & 0XFF;
+  payload[startbyte+7] = (value >> 24) & 0XFF;
+
+  return startbyte+8;
 }

lib/SHT21/SHT21.h

@@ -27,7 +27,7 @@
 #ifndef SHT21_H
 #define SHT21_H
 
-#include <inttypes.h>
+#include "../../include/attsensor.h"
 
 #define SHT21_I2CADDR    0x40
 
@@ -37,12 +37,6 @@
 #define SHT21_HUMINOHOLD 0xF5
 #define SHT21_SOFTRESET  0xFE
 
-struct lora_data {
-  uint8_t bat;
-  int32_t temperature;
-  int32_t humidity;
-} __attribute__ ((packed));
-
 class SHT21
 {
     private:
@@ -50,7 +44,9 @@ class SHT21
 
     public:
         SHT21(void);
-        void getSensorData(lora_data &loradata);
+        uint8_t getSensorData(char *payload, uint8_t startbyte);
+        void initialize(void) {};
+        uint8_t numBytes(void) {return 8;};
 };
 
 #endif

src/config.h.example

@@ -23,12 +23,19 @@
 // Serial Debug Output is not available with this Sensor.
 // #define DEBUG
 
+
+// Number of Active Sensors (used as long as HAS_NO_SENSOR is not enabled)
+// Set to the correct number of enabled sensors below
+// Not doing so will lead to unpredictable results or not work at all
+#define NUM_SENSORS 1
+
 // Define which Sensor is installed
 #define HAS_NO_SENSOR
 // #define HAS_BME280
 // #define HAS_SHT21
 // #define HAS_SG112A
 // #define HAS_MHZ19C
+// #define HAS_SENSAIRS8
 
 
 // How many minutes to sleep between Measuring/Sending

src/main.cpp

@@ -13,6 +13,23 @@
 
 #include "config.h"
 #include "debug.h"
+#include "attsensor.h"
+
+#ifdef HAS_MHZ19C
+  #include <MHZ19C.h>
+#endif
+#ifdef HAS_SG112A
+  #include <SG112A.h>
+#endif
+#ifdef HAS_SENSAIRS8
+  #include <SENSAIRS8.h>
+#endif
+#ifdef HAS_BME280
+  #include <BME280.h>
+#endif
+#ifdef HAS_SHT21
+  #include <SHT21.h>
+#endif
 
 // define the blink function and  BLINK_LED Macro depending
 // on the definition of LED_PIN
@@ -44,30 +61,10 @@ void blink(uint8_t num) {
   #define WS2812B_BLINK(led,r,g,b,ms)
 #endif
 
-// Create the Sensor Objects
+#ifndef HAS_NO_SENSORS
-#if defined HAS_NO_SENSOR
+AttSensor* sensors[NUM_SENSORS];
-  struct lora_data {
-    uint8_t bat;
-  } __attribute ((packed));
-#elif defined HAS_MHZ19C
-  #include <MHZ19C.h>
-  MHZ19C sensor;
-#elif defined HAS_SG112A
-  #include <SG112A.h>
-  SG112A sensor;
-#elif defined HAS_SENSAIRS8
-  #include <SENSAIRS8.h>
-  SENSAIRS8 sensor;
-#elif defined HAS_BME280
-  #include <BME280.h>
-  BME280 sensor;
-#elif defined HAS_SHT21
-  #include <SHT21.h>
-  SHT21 sensor;
-#elif defined HAS_SG112A
-  #include <SG112A.h>
-  SG112A sensor;
 #endif
+int payloadBytes = 1;
 
 // Define some LMIC Callbacks and Variables
 void os_getArtEui (u1_t* buf) {
@@ -196,24 +193,28 @@ uint16_t readSupplyVoltage() { //returns value in millivolts to avoid floating p
 void do_send(osjob_t* j) {
   // Prepare LoRa Data Packet
   // The struct is defined in the sensor class (or above for use without a sensor)
-  lora_data data; 
+  char payload[payloadBytes];
   
   if (LMIC.opmode & OP_TXRXPEND) {
     delay(1);
   } else {
+    uint8_t curByte = 0;
+
     // Add Battery Voltage (0.2V Accuracy stored in 1 byte)
     uint32_t batv = readSupplyVoltage();
-    data.bat = (uint8_t)(batv / 20);
+    payload[curByte] = (uint8_t)(batv / 20);
     if (batv % 20 > 9)
-      data.bat += 1;
+      payload[curByte] += 1;
+    curByte++;
 
     // Get Sensor Readings Into Data Paket
     #ifndef HAS_NO_SENSOR
-    sensor.getSensorData(data);
+    for (int i=0; i < NUM_SENSORS; i++)
+      curByte = sensors[i]->getSensorData(payload, curByte);
     
     // Queue Packet for Sending
     DEBUG_PRINTLN("LoRa-Packet Queued");
-    LMIC_setTxData2(1, (unsigned char *)&data, sizeof(data), 0);
+    LMIC_setTxData2(1, payload, sizeof(payload), 0);
 
     #if defined WS2812B_PIN && (defined HAS_SG112A || defined HAS_MHZ19C)
 
@@ -261,19 +262,46 @@ void setup()
     attachInterrupt(digitalPinToInterrupt(BTN_PIN), btn_press, FALLING);
   #endif
 
+  // Setup all Sensors
+  uint8_t i = 0;
+  #ifdef HAS_MHZ19C
+    sensors[i] = new MHZ19C();
+    payloadBytes += sensors[i]->numBytes();
+    i++;
+  #endif
+  #ifdef HAS_SG112A
+    sensors[i] = new SG112A();
+    payloadBytes += sensors[i]->numBytes();
+    i++;
+  #endif
+  #ifdef HAS_SENSAIRS8
+    sensors[i] = new SENSAIRS8();
+    payloadBytes += sensors[i]->numBytes();
+    i++;
+  #endif
+  #ifdef HAS_BME280
+    sensors[i] = new BME280();
+    payloadBytes += sensors[i]->numBytes();
+    i++;
+  #endif
+  #ifdef HAS_SHT21
+    sensors[i] = new SHT21();
+    payloadBytes += sensors[i]->numBytes();
+    i++;
+  #endif
+
+
+  // Initialize all Sensors
+  #ifndef HAS_NO_SENSOR
+  for (i = 0; i < NUM_SENSORS; i++)
+    sensors[i]->initialize();
+  #endif
+
   // Set RTC
   while (RTC.STATUS > 0) {}
   RTC.CLKSEL = RTC_CLKSEL_INT1K_gc;
   while (RTC.PITSTATUS > 0) {}
 
-  // Initialize Sensor(s)
-  #ifdef HAS_BME280
-  sensor.getCalData();
-  #endif
-  #ifdef HAS_MHZ19C
-  sensor.initialize();
-  #endif
-
   // Setup LMIC
   DEBUG_PRINT("Initializing LMIC...")
   os_init();