nodemcu/esp8266 max31865 pt100
Posted: Tue Feb 27, 2018 7:33 pmI am attempting to program a NodeMCU through the Arduino IDE to read data from a PT100 sensor through a Max31865. Currently the serial output is saying the temperature sensor is reading the max value. Any idea where I went wrong? If there is another library or an example with a simple temperature output I would appreciate the information. I did also post this on the Arduino forum.
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/***************************************************
This is a library for the Adafruit PT100/P1000 RTD Sensor w/MAX31865
Designed specifically to work with the Adafruit RTD Sensor
----> https://www.adafruit.com/products/3328
This sensor uses SPI to communicate, 4 pins are required to
interface
Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing
products from Adafruit!
Written by Limor Fried/Ladyada for Adafruit Industries.
BSD license, all text above must be included in any redistribution
****************************************************/
#include <Adafruit_MAX31865.h>
// Use software SPI: CS, DI, DO, CLK
//Adafruit_MAX31865 max1 = Adafruit_MAX31865(14, 11, 12, 13);
// use hardware SPI, just pass in the CS pin
Adafruit_MAX31865 max1 = Adafruit_MAX31865(14);
// The value of the Rref resistor. Use 430.0!
#define RREF 431.0
void setup() {
Serial.begin(115200);
Serial.println("Adafruit MAX31865 PT100 Sensor Test!");
max1.begin(MAX31865_3WIRE); // set to 2WIRE or 4WIRE as necessary
}
void loop() {
uint16_t rtd = max1.readRTD();
Serial.print("RTD value: "); Serial.println(rtd);
float ratio = rtd;
ratio /= 32768;
//Serial.print("Ratio = "); Serial.println(ratio,8);
//Serial.print("Resistance = "); Serial.println(RREF*ratio,8);
Serial.print("Temperature = "); Serial.println(max1.temperature(100, RREF));
/* // Check and print any faults
uint8_t fault = max1.readFault();
if (fault) {
Serial.print("Fault 0x"); Serial.println(fault, HEX);
if (fault & MAX31865_FAULT_HIGHTHRESH) {
Serial.println("RTD High Threshold");
}
if (fault & MAX31865_FAULT_LOWTHRESH) {
Serial.println("RTD Low Threshold");
}
if (fault & MAX31865_FAULT_REFINLOW) {
Serial.println("REFIN- > 0.85 x Bias");
}
if (fault & MAX31865_FAULT_REFINHIGH) {
Serial.println("REFIN- < 0.85 x Bias - FORCE- open");
}
if (fault & MAX31865_FAULT_RTDINLOW) {
Serial.println("RTDIN- < 0.85 x Bias - FORCE- open");
}
if (fault & MAX31865_FAULT_OVUV) {
Serial.println("Under/Over voltage");
}
max1.clearFault();
}
Serial.println();
*/
delay(1000);
}NodeMCU Wiring
Breakout Wiring
NodeMCU Wiring