96 lines
3.5 KiB
C++
96 lines
3.5 KiB
C++
// GrovePi Example for using the Grove Rotary Angle Sensor (Potentiometer) and the Grove LED to create LED sweep
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//
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// Modules:
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// http://www.seeedstudio.com/wiki/Grove_-_Rotary_Angle_Sensor
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// http://www.seeedstudio.com/wiki/Grove_-_LED_Socket_Kit
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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_rotary_angle_sensor.cpp -o grove_rotary_angle_sensor.out -> without grovepicpp package installed
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// sudo g++ -Wall -lgrovepicpp grove_rotary_angle_sensor.cpp -o grove_rotary_angle_sensor.out -> with grovepicpp package installed
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int main()
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{
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int potentiometer_pin = 0; // potentiometer is connected to A0 port
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int LED_pin = 5; // potentiometer is connected to D5 port
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int adc_ref = 5; // reference voltage of ADC is 5V
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int grove_ref_vcc = 5; // Grove's reference voltage is 5V, regularly
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int full_angle = 300; // max turning angle for the potentiomater (almost a complete turn)
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try
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{
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initGrovePi();
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pinMode(potentiometer_pin, INPUT);
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pinMode(LED_pin, OUTPUT);
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// do this indefinitely
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while(true)
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{
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// start reading potentiometer's values
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int sensor_value = analogRead(potentiometer_pin);
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// calculate voltage
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float voltage = (float)(sensor_value) * adc_ref / 1023;
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// calculate rotation in degrees (0 to 300)
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float degrees = voltage * full_angle / grove_ref_vcc;
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// and calculate brightness for the LED
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// basically we map values 0->300 to 0->255
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int brightness = int(degrees / full_angle * 255);
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float percentage_brightness = 100 * float(brightness) / 255;
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// and give a PWM output to the LED
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analogWrite(LED_pin, brightness);
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// and display status data onto the terminal
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printf("[rotar pin %d][led pin %d][sensor value = %d][voltage = %.2f][degrees = %.1f][brightness = %.2f%%]\n",
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potentiometer_pin, LED_pin, sensor_value, voltage, degrees, percentage_brightness);
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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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// wait 20 ms for the next reading
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// this equates to a rate of 50Hz
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// so there are 50 reads / second -> more than enough
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delay(20);
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return 0;
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}
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