add TSL235R

Author: RobTillaart

libraries/TSL235R/.arduino-ci.yml

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+compile:
+  # Choosing to run compilation tests on 2 different Arduino platforms
+  platforms:
+    - uno
+    - leonardo
+    - due
+    - zero

libraries/TSL235R/.github/workflows/arduino-lint.yml

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+
+name: Arduino-lint
+
+on: [push, pull_request]
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: arduino/arduino-lint-action@v1
+        with:
+          library-manager: update
+          compliance: strict

libraries/TSL235R/.github/workflows/arduino_test_runner.yml

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+---
+name: Arduino CI
+
+on: [push, pull_request]
+
+jobs:
+  arduino_ci:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: Arduino-CI/action@master
+          #   Arduino-CI/[email protected]

libraries/TSL235R/.github/workflows/jsoncheck.yml

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+name: JSON check
+
+on:
+  push:
+    paths:
+      - '**.json'
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: json-syntax-check
+        uses: limitusus/json-syntax-check@v1
+        with:
+          pattern: "\\.json$"
+

libraries/TSL235R/LICENSE

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+MIT License
+
+Copyright (c) 2021-2021 Rob Tillaart
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

libraries/TSL235R/README.md

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+
+[![Arduino CI](https://github.com/RobTillaart/TSL235R/workflows/Arduino%20CI/badge.svg)](https://github.com/marketplace/actions/arduino_ci)
+[![License: MIT](https://img.shields.io/badge/license-MIT-green.svg)](https://github.com/RobTillaart/TSL235R/blob/master/LICENSE)
+[![GitHub release](https://img.shields.io/github/release/RobTillaart/TSL235R.svg?maxAge=3600)](https://github.com/RobTillaart/TSL235R/releases)
+
+
+# TSL235R
+
+Arduino library for the TSL235R light to frequency convertor.
+
+
+## Description
+
+This library does not measure the frequency but has some functions to compensate e.g. 
+for wavelength and voltage used.
+
+The library is not tested extensively yet.
+
+The sensor operating voltage is between 2.7 and 5.5 max.
+
+For measurements below 1uW/cm2 one bests measures for multiple seconds
+Above 1 uW/cm2 1 second or shorter is OK. 
+
+Note that for longer and shorter measurements than 1 second one must convert the
+value to Hz, which is the nr of pulses in 1 second.
+
+
+## Connection
+
+```
+// PIN 1 - GND
+// PIN 2 - VDD      2.7 V .. 5.5 V
+// PIN 3 - SIGNAL   1 Hz  .. 800 KHz
+```
+
+
+## Interface
+
+- **TSL235R(float voltage = 5.0)** constructor, optionally one can give the operational voltage 
+to add a small correction (< 1.5%)
+- **float irradiance(uint32_t Hz)** returns the irradiance in uW/cm2.
+NOte that Hz implies the measured pulses for 1 second.
+- **float irradiance(uint32_t pulses, uint32_t milliseconds)** returns the irradiance in uW/cm2
+This formula is used for other duration than 1 second.
+To get irradiance in W/m2 one must divide by 100.
+- **float getFactor()** returns the inner conversion factor from Hz to Watt/cm2.
+- **void setWavelength(uint16_t wavelength = 635)** sets the wavelength so the formulas can use a correction factor. At the default wavelength of 635 nm the wavelength correction factor == 1.0
+- **uint16_t getWavelength()** returns the set wavelength. Convenience function.
+- **float getWaveLengthFactor()** returns the wavelength correction factor. 
+As the sensor is most sensitive around 750 nm this value helps to normalize the signal.
+This works only for (almost) monochomatic light.
+- **void setVoltage(float voltage)** sets the voltage so the formulas can use a correction factor.
+This voltage correction factor is rather small < 1.5%
+- **float getVoltage()** returns the set voltage. Convenience function.
+
+
+## Operations
+
+See examples for typical usage.
+
+
+## Future
+
+- investigate correction factor for white light and mixed light sources.

libraries/TSL235R/TSL235R .cpp

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+//
+//    FILE: TSL235R.cpp
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.0
+// PURPOSE: library fot the TSL235R light to frequency convertor
+//
+//  HISTORY:
+//  0.1.0   2020-05-29  initial version
+
+
+#include "TSL235R.h"
+
+
+TSL235R::TSL235R(float voltage)
+{
+  _voltage = voltage;
+  calculateFactor();
+}
+
+
+float TSL235R::irradiance(uint32_t Hz)
+{
+  return Hz * _factor;
+}
+
+
+float TSL235R::irradiance(uint32_t pulses, uint32_t milliseconds)
+{
+  return (pulses * 1000.0 * _factor) / milliseconds;
+}
+
+
+void TSL235R::setWavelength(uint16_t wavelength)
+{
+  _waveLength = wavelength;
+  calculateFactor();
+}
+
+
+void TSL235R::setVoltage(float voltage)
+{
+  _voltage = voltage;
+  calculateFactor();
+}
+
+void TSL235R::calculateFactor()
+{
+  // figure 1 datasheet
+  // 1 Khz crosses the line at 35/230 between 1 and 10.
+  // so the correctiion factor is 10^0.15217 = 1.419659 = 1.42
+  // as the graph is in kHz we need to correct a factor 1000
+  // as the irradiance function gets Hz
+  const float cf = 0.00142;
+  _waveLengthFactor = calcWLF(_waveLength);
+
+  _voltageFactor = 0.988 + (_voltage - 2.7) * (0.015 / 2.8);
+  _factor = cf * _waveLengthFactor * _voltageFactor;
+}
+
+
+float TSL235R::calcWLF(uint16_t _waveLength)
+{
+  // figure 2 datasheet
+  // 635 nm is reference 1.000
+  // remaining is linear interpolated between points in the graph
+  float in[]  = { 300, 350,  400, 500,  600,  635,  700,  750,  800,  850,  900,  1000, 1100};
+  float out[] = { 0.1, 0.35, 0.5, 0.75, 0.93, 1.00, 1.15, 1.20, 1.15, 1.10, 0.95, 0.40, 0.10};
+  return 1.0 / multiMap(_waveLength, in, out, 13);
+}
+
+
+float TSL235R::multiMap(float val, float * _in, float * _out, uint8_t size)
+{
+  // take care the value is within range
+  // val = constrain(val, _in[0], _in[size-1]);
+  if (val <= _in[0]) return _out[0];
+  if (val >= _in[size-1]) return _out[size-1];
+
+  // search right interval
+  uint8_t pos = 1;  // _in[0] allready tested
+  while(val > _in[pos]) pos++;
+
+  // this will handle all exact "points" in the _in array
+  if (val == _in[pos]) return _out[pos];
+
+  // interpolate in the right segment for the rest
+  return (val - _in[pos-1]) * (_out[pos] - _out[pos-1]) / (_in[pos] - _in[pos-1]) + _out[pos-1];
+}
+
+
+
+// -- END OF FILE --

libraries/TSL235R/TSL235R.h

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+#pragma once
+//
+//    FILE: TSL235R.h
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.0
+// PURPOSE: library fot the TSL235R light to frequency convertor
+
+
+#define TSL235R_LIB_VERSION     (F("0.1.0"))
+
+#include "Arduino.h"
+
+
+class TSL235R
+{
+public:
+
+  TSL235R(float voltage = 5.0);
+
+  float    irradiance(uint32_t Hz);
+  float    irradiance(uint32_t pulses, uint32_t milliseconds);
+  float    getFactor()           { return _factor; };
+
+  void     setWavelength(uint16_t wavelength = 635);
+  uint16_t getWavelength()       { return _waveLength; }
+  float    getWaveLengthFactor() { return _waveLengthFactor; }
+
+  void     setVoltage(float voltage = 5.0);
+  float    getVoltage()          { return _voltage; };
+  float    getVoltageFactor()    { return _voltageFactor; };
+
+private:
+  uint16_t _waveLength       = 635;
+  float    _waveLengthFactor = 1.0;
+  float    _voltage          = 5.0;
+  float    _voltageFactor    = 1.0;
+  float    _factor           = 1.2;
+
+  void     calculateFactor();
+  float    calcWLF(uint16_t _waveLength);
+  float    multiMap(float val, float * _in, float * _out, uint8_t size);
+};
+
+
+// -- END OF FILE --

libraries/TSL235R/examples/TSL235R_demo/TSL235R_demo.ino

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+//
+//    FILE: TSL235R_demo.ino
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.0
+// PURPOSE: demo
+//    DATE: 2021-05-29
+
+//
+// Digital Pin layout ARDUINO
+// =============================
+//  2     IRQ 0    - to TSL235R
+// 
+// PIN 1 - GND
+// PIN 2 - VDD - 5V
+// PIN 3 - SIGNAL
+//
+
+
+#include "TSL235R.h"
+
+
+TSL235R  mySensor;
+
+volatile uint32_t cnt = 0;
+uint32_t oldcnt = 0;
+uint32_t t = 0;
+uint32_t lastMeasurement = 0;
+
+
+void count_irq()
+{
+  cnt++;
+}
+
+
+///////////////////////////////////////////////////////////////////
+//
+// SETUP
+//
+void setup()
+{
+  Serial.begin(115200);
+  Serial.println(__FILE__);
+
+  pinMode(2, INPUT);
+  digitalWrite(2, HIGH);
+  attachInterrupt(0, count_irq, RISING);
+
+  mySensor.setWavelength(450);
+}
+
+
+void loop()
+{
+  uint32_t now = millis();
+  if (now - lastMeasurement >= 1000)
+  {
+    lastMeasurement = now;
+    t = cnt;
+    uint32_t Hz = t - oldcnt;
+    oldcnt = t;
+    
+    Serial.print("irradiance:\t");
+    Serial.print(mySensor.irradiance(Hz));   // assumption 1 second
+    Serial.println(" uW/cm2");
+  }
+}
+
+// -- END OF FILE --