Merge pull request #158 from EnviroDIY/master

Pulling master in to PaleoTerraRedox to use current modular formats

sensor_tests/Apogee_SQ212_AnalogTest/Apogee_SQ212_AnalogTest.ino

@@ -0,0 +1,81 @@
+/*****************************************************************************
+Apogee_SQ212_AnalogTest.ino
+Written By:  Anthony Aufdenkampe <aaufdenkampe@limno.com>
+Adapted from mayfly_turbidity_test1.ino by Sara Damiano (sdamiano@stroudcenter.org)
+Development Environment: PlatformIO 3.4
+Hardware Platform: EnviroDIY Mayfly Arduino Datalogger
+Software License: BSD-3.
+  Copyright (c) 2017, Stroud Water Research Center (SWRC)
+  and the EnviroDIY Development Team
+
+Apogee SQ-212 Quantum Light sensor measures photosynthetically active radiation (PAR)
+and is typically defined as total radiation across a range of 400 to 700 nm.
+PAR is often expressed as photosynthetic photon flux density (PPFD):
+photon flux in units of micromoles per square meter per second (μmol m-2 s-1,
+equal to microEinsteins per square meter per second) summed from 400 to 700 nm.
+https://www.apogeeinstruments.com/sq-212-amplified-0-2-5-volt-sun-calibration-quantum-sensor/
+
+For derivation of the Analog to Digital Conversion Factor (17585) see:
+https://github.com/EnviroDIY/ModularSensors/issues/54#issuecomment-306180076
+https://github.com/adafruit/Adafruit_ADS1X15/blob/master/examples/singleended/singleended.pde
+
+*****************************************************************************/
+
+#include <Arduino.h>
+#include <Adafruit_ADS1015.h>
+Adafruit_ADS1115 ads;     /* Use this for the 16-bit version */
+
+float PhotosyntheticPhotonFluxDensity;   //variable(s) to hold the calculated values
+int16_t adc0; // adc1, adc2, adc3;      //tells which channels are to be read
+float voltage;
+
+void analogPAR()     // function that takes reading from analog OBS3+ turbidity sensor
+{
+    adc0 = ads.readADC_SingleEnded(0);
+    //now convert bits into millivolts. Calibrated Output Range = 0 to 2.5 V
+    voltage = adc0 * 0.1875/1000;  // in units of V. See Adafruit_ADS1X15 library for AD conversion factors.
+              // Alternately = = adc0 * 3.3V / 17600.0 register bits,
+              // where 3.3V is the voltage of the Mayfly board and 17600 = 3.3V / 0.1875 mV/bit
+    //Calibration Factor (Reciprocal of Sensitivity) = 1.0 μmol m-2 s-1 per mV;
+    PhotosyntheticPhotonFluxDensity =  1 * voltage * 1000 ;  // in units of μmol m-2 s-1
+
+    Serial.print(F("ads.readADC_SingleEnded(0): "));
+    Serial.print(adc0);
+    Serial.print("\t\t");
+
+    Serial.print(F("Voltage: "));
+    Serial.print(voltage, 4);
+    Serial.print("\t\t");
+
+    Serial.print(F("calibResult: "));
+    Serial.println(PhotosyntheticPhotonFluxDensity);
+}
+
+
+void setup() {
+    Serial.begin(57600);
+    ads.begin();       //begin adafruit ADS1015
+    pinMode(22, OUTPUT);
+    pinMode(8, OUTPUT);
+}
+
+void loop() {
+    Serial.println("---------------------------------");
+    // Power the sensor
+    digitalWrite(22, HIGH);
+    delay(1000);
+
+    // Turn on the LED to show we're taking a reading
+    digitalWrite(8, HIGH);
+
+    analogPAR();
+    delay(5000);
+
+    // Turn off sensor power
+    digitalWrite(22, LOW);
+
+    // Turn off the LED to show we're done with the reading
+    digitalWrite(8, LOW);
+
+    delay(1000);
+}