52 lines
1.4 KiB
C++
52 lines
1.4 KiB
C++
// SPDX-FileCopyrightText: 2011 Limor Fried/ladyada for Adafruit Industries
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//
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// SPDX-License-Identifier: MIT
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// thermistor-2.ino Intermediate test program for a thermistor. Adafruit Learning System Tutorial
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// https://learn.adafruit.com/thermistor/using-a-thermistor by Limor Fried, Adafruit Industries
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// MIT License - please keep attribution and please consider buying parts from Adafruit
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// which analog pin to connect
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#define THERMISTORPIN A0
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// how many samples to take and average, more takes longer
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// but is more 'smooth'
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#define NUMSAMPLES 5
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// the value of the 'other' resistor
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#define SERIESRESISTOR 10000
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int samples[NUMSAMPLES];
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void setup(void) {
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Serial.begin(9600);
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// connect AREF to 3.3V and use that as VCC, less noisy!
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analogReference(EXTERNAL);
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}
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void loop(void) {
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uint8_t i;
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float average;
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// take N samples in a row, with a slight delay
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for (i=0; i< NUMSAMPLES; i++) {
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samples[i] = analogRead(THERMISTORPIN);
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delay(10);
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}
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// average all the samples out
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average = 0;
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for (i=0; i< NUMSAMPLES; i++) {
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average += samples[i];
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}
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average /= NUMSAMPLES;
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Serial.print("Average analog reading ");
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Serial.println(average);
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// convert the value to resistance
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average = 1023 / average - 1;
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average = SERIESRESISTOR / average;
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Serial.print("Thermistor resistance ");
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Serial.println(average);
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delay(1000);
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}
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