Hello,
I bought these two items
https://www.amazon.com/gp/product/B07DP3LYPX
https://www.amazon.com/Adafruit-PT100-Temperature-Sensor-Amplifier/dp/B01N4LEVZN/
and I am using the stock ada fruit code. I did solder the "2/3 wire" jumper, break the "24 3" trace and also soldered the 3 jumper.
This is the result I am getting back
00:56:46.155 -> Adafruit MAX31865 PT100 Sensor Test!
00:56:46.247 -> RTD value: 832
00:56:46.247 -> Ratio = 0.02539062
00:56:46.247 -> Resistance = 10.91796875
00:56:46.247 -> Temperature = -217.48
00:56:46.340 ->
00:56:47.384 -> RTD value: 831
00:56:47.384 -> Ratio = 0.02536011
00:56:47.384 -> Resistance = 10.90484619
00:56:47.384 -> Temperature = -217.48
code (from adafruit)
/***************************************************
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 thermo = Adafruit_MAX31865(10, 11, 12, 13);
// use hardware SPI, just pass in the CS pin
//Adafruit_MAX31865 thermo = Adafruit_MAX31865(10);
// The value of the Rref resistor. Use 430.0 for PT100 and 4300.0 for PT1000
#define RREF 430.0
// The 'nominal' 0-degrees-C resistance of the sensor
// 100.0 for PT100, 1000.0 for PT1000
#define RNOMINAL 100.0
void setup() {
Serial.begin(115200);
Serial.println("Adafruit MAX31865 PT100 Sensor Test!");
thermo.begin(MAX31865_3WIRE); // set to 2WIRE or 4WIRE as necessary
}
void loop() {
uint16_t rtd = thermo.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(thermo.temperature(RNOMINAL, RREF));
// Check and print any faults
uint8_t fault = thermo.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");
}
thermo.clearFault();
}
Serial.println();
delay(1000);
}
The only thing that is weird on this is that my sensor has 2 negatives and 1 positive (while adafruits example has 2positives and 1negative) This shouldnt matter as I understand the PT100 is only a resistor.
Also in the ada fruit example, it appears that they have a cap around (row 11)
Thanks for any help you can give