Add support for EZO™ pH Circuit

code/espurna/config/arduino.h

@@ -176,3 +176,4 @@
 //#define TMP3X_SUPPORT          1
 //#define V9261F_SUPPORT         1
 //#define VL53L1X_SUPPORT        1
+//#define EZOPH_SUPPORT          1

code/espurna/config/progmem.h

@@ -232,6 +232,9 @@ PROGMEM const char espurna_sensors[] =
     #if VL53L1X_SUPPORT
         "VL53L1X "
     #endif
+    #if EZOPH_SUPPORT
+        "EZOPH "
+    #endif
     "";
 
 
@@ -246,7 +249,7 @@ PROGMEM const unsigned char magnitude_decimals[] = {
     3, 0,
     4, 4, // Geiger Counter decimals
     0,
-    0, 0, 0    // NO2, CO, Ohms
+    0, 0, 0, 3    // NO2, CO, Ohms, pH
 };
 
 PROGMEM const char magnitude_unknown_topic[] = "unknown";
@@ -280,6 +283,7 @@ PROGMEM const char magnitude_count_topic[] = "count";
 PROGMEM const char magnitude_no2_topic[] = "no2";
 PROGMEM const char magnitude_co_topic[] = "co";
 PROGMEM const char magnitude_resistance_topic[] = "resistance";
+PROGMEM const char magnitude_ph_topic[] = "ph";
 
 PROGMEM const char* const magnitude_topics[] = {
     magnitude_unknown_topic, magnitude_temperature_topic, magnitude_humidity_topic,
@@ -293,7 +297,7 @@ PROGMEM const char* const magnitude_topics[] = {
     magnitude_distance_topic, magnitude_hcho_topic,
     magnitude_geiger_cpm_topic, magnitude_geiger_sv_topic,
     magnitude_count_topic,
-    magnitude_no2_topic, magnitude_co_topic, magnitude_resistance_topic
+    magnitude_no2_topic, magnitude_co_topic, magnitude_resistance_topic, magnitude_ph_topic
 };
 
 PROGMEM const char magnitude_empty[] = "";
@@ -330,7 +334,8 @@ PROGMEM const char* const magnitude_units[] = {
     magnitude_geiger_cpm, magnitude_geiger_sv,                  // Geiger counter units
     magnitude_empty,                                            //
     magnitude_ppm, magnitude_ppm,                               // NO2 & CO2
-    magnitude_resistance
+    magnitude_resistance,
+    magnitude_empty                                             // pH
 };
 
 #endif

code/espurna/config/sensors.h

@@ -780,6 +780,25 @@
 #define VEML6075_DYNAMIC_MODE             VEML6075::DYNAMIC_NORMAL  // The dynamic mode can either be normal or high. In high
 #endif                                                              // dynamic mode, the resolution increases by about two
                                                                     // times.
+// EZOPH pH meter
+// Enable support by passing EZOPH_SUPPORT=1 build flag
+//------------------------------------------------------------------------------
+
+#ifndef EZOPH_SUPPORT
+#define EZOPH_SUPPORT                0
+#endif
+
+#ifndef EZOPH_RX_PIN
+#define EZOPH_RX_PIN                 13      // Software serial RX GPIO
+#endif
+
+#ifndef EZOPH_TX_PIN
+#define EZOPH_TX_PIN                 15      // Software serial TX GPIO
+#endif
+
+#ifndef EZOPH_SYNC_INTERVAL
+#define EZOPH_SYNC_INTERVAL          1000    // Amount of time (in ms) sync new readings.
+#endif
 
 // =============================================================================
 // Sensor helpers configuration - can't move to dependencies.h
@@ -818,7 +837,8 @@
     TMP3X_SUPPORT || \
     V9261F_SUPPORT || \
     VEML6075_SUPPORT || \
-    VL53L1X_SUPPORT \
+    VL53L1X_SUPPORT || \
+    EZOPH_SUPPORT \
 )
 #endif
 
@@ -988,4 +1008,8 @@
     #include "../sensors/VL53L1XSensor.h"
 #endif
 
+#if EZOPH_SUPPORT
+    #include "../sensors/EZOPHSensor.h"
+#endif
+
 #endif // SENSOR_SUPPORT

code/espurna/config/types.h

@@ -282,6 +282,7 @@
 #define SENSOR_PULSEMETER_ID        30
 #define SENSOR_VEML6075_ID          31
 #define SENSOR_VL53L1X_ID           32
+#define SENSOR_EZOPH_ID             33
 
 //--------------------------------------------------------------------------------
 // Magnitudes
@@ -319,5 +320,6 @@
 #define MAGNITUDE_NO2               28
 #define MAGNITUDE_CO                29
 #define MAGNITUDE_RESISTANCE        30
+#define MAGNITUDE_PH                31
 
-#define MAGNITUDE_MAX               31
+#define MAGNITUDE_MAX               32

code/espurna/sensor.ino

@@ -738,6 +738,15 @@ void _sensorLoad() {
         _sensors.push_back(sensor);
     }
     #endif
+
+    #if EZOPH_SUPPORT
+    {
+        EZOPHSensor * sensor = new EZOPHSensor();
+        sensor->setRX(EZOPH_RX_PIN);
+        sensor->setTX(EZOPH_TX_PIN);
+        _sensors.push_back(sensor);
+    }
+    #endif
 }
 
 void _sensorCallback(unsigned char i, unsigned char type, double value) {

code/espurna/sensors/EZOPHSensor.h

@@ -0,0 +1,212 @@
+// -----------------------------------------------------------------------------
+// EZO™ pH Circuit from Atlas Scientific
+//
+// Uses SoftwareSerial library
+// Copyright (C) 2018 by Rui Marinho <ruipmarinho at gmail dot com>
+// -----------------------------------------------------------------------------
+
+#if SENSOR_SUPPORT && EZOPH_SUPPORT
+
+#pragma once
+
+#include "Arduino.h"
+#include "BaseSensor.h"
+#include <SoftwareSerial.h>
+
+class EZOPHSensor : public BaseSensor {
+
+    public:
+
+        // ---------------------------------------------------------------------
+        // Public
+        // ---------------------------------------------------------------------
+
+        EZOPHSensor(): BaseSensor() {
+            _count = 1;
+            _sensor_id = SENSOR_EZOPH_ID;
+        }
+
+        ~EZOPHSensor() {
+            if (_serial) delete _serial;
+        }
+
+        // ---------------------------------------------------------------------
+
+        void setRX(unsigned char pin_rx) {
+            if (_pin_rx == pin_rx) return;
+            _pin_rx = pin_rx;
+            _dirty = true;
+        }
+
+        void setTX(unsigned char pin_tx) {
+            if (_pin_tx == pin_tx) return;
+            _pin_tx = pin_tx;
+            _dirty = true;
+        }
+
+        // ---------------------------------------------------------------------
+
+        unsigned char getRX() {
+            return _pin_rx;
+        }
+
+        unsigned char getTX() {
+            return _pin_tx;
+        }
+
+        // ---------------------------------------------------------------------
+        // Sensor API
+        // ---------------------------------------------------------------------
+
+        // Initialization method, must be idempotent
+        void begin() {
+            if (!_dirty) return;
+
+            if (_serial) delete _serial;
+
+            _serial = new SoftwareSerial(_pin_rx, _pin_tx);
+            _serial->enableIntTx(false);
+            _serial->begin(9600);
+
+            _ready = true;
+            _dirty = false;
+        }
+
+        // Descriptive name of the sensor
+        String description() {
+            char buffer[28];
+            snprintf(buffer, sizeof(buffer), "EZOPH @ SwSerial(%u,%u)", _pin_rx, _pin_tx);
+            return String(buffer);
+        }
+
+        // Descriptive name of the slot # index
+        String slot(unsigned char index) {
+            return description();
+        };
+
+        // Address of the sensor (it could be the GPIO or I2C address)
+        String address(unsigned char index) {
+            char buffer[6];
+            snprintf(buffer, sizeof(buffer), "%u:%u", _pin_rx, _pin_tx);
+            return String(buffer);
+        }
+
+        // Type for slot # index
+        unsigned char type(unsigned char index) {
+            if (index == 0) return MAGNITUDE_PH;
+            return MAGNITUDE_NONE;
+        }
+
+        void tick() {
+            _setup();
+            _read();
+        }
+
+        // Current value for slot # index
+        double value(unsigned char index) {
+            if (index == 0) return _ph;
+            return 0;
+        }
+
+
+
+    protected:
+
+        // ---------------------------------------------------------------------
+        // Protected
+        // ---------------------------------------------------------------------
+
+        void _setup() {
+          if (_sync_responded) {
+            return;
+          }
+
+          _error = SENSOR_ERROR_WARM_UP;
+
+          String sync_serial = "";
+          sync_serial.reserve(30);
+
+          if (!_sync_requested) {
+              _serial->write(67); // C
+              _serial->write(44); // ,
+              _serial->write(63); // ?
+              _serial->write(13); // \r
+              _serial->flush();
+
+              _sync_requested = true;
+          }
+
+          while ((_serial->available() > 0)) {
+              char sync_char = (char)_serial->read();
+              sync_serial += sync_char;
+
+              if (sync_char == '\r') {
+                break;
+              }
+          }
+
+          if (sync_serial.startsWith("?C,")) {
+              _sync_interval = sync_serial.substring(sync_serial.indexOf(",") + 1).toInt() * 1000;
+
+              if (_sync_interval == 0) {
+                  _error = SENSOR_ERROR_OTHER;
+                  return;
+              }
+          }
+
+          if (sync_serial.startsWith("*OK")) {
+              _sync_responded = true;
+          }
+
+          if (!_sync_responded) {
+            return;
+          }
+
+          _error = SENSOR_ERROR_OK;
+        }
+
+        void _read() {
+            if (_error != SENSOR_ERROR_OK) {
+              return;
+            }
+
+            if (millis() - _ts <= _sync_interval) {
+              return;
+            }
+
+            _ts = millis();
+
+            String ph_serial = "";
+            ph_serial.reserve(30);
+
+            while ((_serial->available() > 0)) {
+                char ph_char = (char)_serial->read();
+                ph_serial += ph_char;
+
+                if (ph_char == '\r') {
+                  break;
+                }
+            }
+
+            if (ph_serial == "*ER") {
+              _error = SENSOR_ERROR_OTHER;
+              return;
+            }
+
+            _ph = ph_serial.toFloat();
+
+            _error = SENSOR_ERROR_OK;
+        }
+
+        bool _sync_requested = false;
+        bool _sync_responded = false;
+        unsigned long _sync_interval = 100000; // Maximum continuous reading interval allowed is 99000 milliseconds.
+        unsigned long _ts = 0;
+        double _ph = 0;
+        unsigned int _pin_rx;
+        unsigned int _pin_tx;
+        SoftwareSerial * _serial = NULL;
+
+};
+
+#endif // SENSOR_SUPPORT && EZOPH_SUPPORT

code/html/custom.js

@@ -47,7 +47,8 @@ function sensorName(id) {
         "Events", "PMSX003", "BMX280", "MHZ19", "SI7021",
         "SHT3X I2C", "BH1750", "PZEM004T", "AM2320 I2C", "GUVAS12SD",
         "TMP3X", "Sonar", "SenseAir", "GeigerTicks", "GeigerCPM",
-        "NTC", "SDS011", "MICS2710", "MICS5525", "VL53L1X", "VEML6075"
+        "NTC", "SDS011", "MICS2710", "MICS5525", "VL53L1X", "VEML6075",
+        "EZOPH"
     ];
     if (1 <= id && id <= names.length) {
         return names[id - 1];
@@ -64,7 +65,7 @@ function magnitudeType(type) {
         "PM1.0", "PM2.5", "PM10", "CO2", "Lux", "UVA", "UVB", "UV Index", "Distance" , "HCHO",
         "Local Dose Rate", "Local Dose Rate",
         "Count",
-        "NO2", "CO", "Resistance"
+        "NO2", "CO", "Resistance", "pH"
     ];
     if (1 <= type && type <= types.length) {
         return types[type - 1];