96 lines
3.4 KiB
C++
96 lines
3.4 KiB
C++
//
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// GrovePi Example for using the Grove Light Sensor and the LED together to turn the LED On and OFF if the background light is greater than a threshold.
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// Modules:
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// http://www.seeedstudio.com/wiki/Grove_-_Light_Sensor
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// http://www.seeedstudio.com/wiki/Grove_-_LED_Socket_Kit
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//
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// The GrovePi connects the Raspberry Pi and Grove sensors. You can learn more about GrovePi here: http://www.dexterindustries.com/GrovePi
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//
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// Have a question about this example? Ask on the forums here: http://forum.dexterindustries.com/c/grovepi
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//
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/*
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## License
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The MIT License (MIT)
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GrovePi for the Raspberry Pi: an open source platform for connecting Grove Sensors to the Raspberry Pi.
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Copyright (C) 2017 Dexter Industries
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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THE SOFTWARE.
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*/
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#include "grovepi.h"
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using namespace GrovePi;
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// sudo g++ -Wall grovepi.cpp grove_light_sensor.cpp -o grove_ligh_sensor.out -> without grovepicpp package installed
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// sudo g++ -Wall -lgrovepicpp grove_light_sensor.cpp -o grove_ligh_sensor.out -> with grovepicpp package installed
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int main()
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{
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int light_sensor_pin = 0; // analog port A0 for the Grove Light Sensor
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int LED_pin = 4; // digital port D4 for the Grove LED
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int threshold = 10; // threshold value in kOhm for the Grove Light Sensor
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int sensor_value; // variable to hold the Grove Light Sensor value
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float resistance; // variable to hold the Grove Light Sensor's resistance value
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try
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{
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// initialize communication with the GrovePi
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initGrovePi();
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// set the LED & Light pins accordingly
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pinMode(light_sensor_pin, INPUT);
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pinMode(LED_pin, OUTPUT);
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while(true)
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{
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// start reading the value on the Light Sensor
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sensor_value = analogRead(light_sensor_pin);
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resistance = (float)(1023 - sensor_value) * 10 / sensor_value;
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printf("[led pin %d][light pin %d][sensor value = %d][resistance = %.2f]", LED_pin, light_sensor_pin, sensor_value, resistance);
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// check if the resistance gets beyond the threshold
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// value in kOhm (check how a light sensor works)
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// and turn ON/OFF the LED on the associated pin accordingly
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if(resistance > threshold)
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{
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digitalWrite(LED_pin, HIGH);
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printf("[led ON]\n");
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}
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else
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{
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digitalWrite(LED_pin, LOW);
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printf("[led OFF]\n");
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}
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// wait 200 ms for the next reading
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delay(200);
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}
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}
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catch(I2CError &error)
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{
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printf(error.detail());
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return -1;
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}
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return 0;
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}
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