I am back home guys. The new adafruit board arrived and i just tried to run it with the example adafruit liberary code.
Unfortunatly it still doens't work. But now the serial monitor gave error message at least once.. i could not replicate the error code.
i did it like that.. the serial monitor was just this and no fluctations.
// Use software SPI: CS, DI, DO, CLK
//Adafruit_MAX31865 thermo = Adafruit_MAX31865(5, 23, 19, 18);
// use hardware SPI, just pass in the CS pin
Adafruit_MAX31865 thermo = Adafruit_MAX31865(5);
sm:
Adafruit MAX31865 PT100 Sensor Test!
RTD value: 0
Ratio = 0.00000000
Resistance = 0.00000000
Temperature = -242.02
RTD value: 0
Ratio = 0.00000000
Resistance = 0.00000000
Temperature = -242.02
RTD value: 0
Ratio = 0.00000000
Resistance = 0.00000000
Temperature = -242.02
As I said in post #29
The temperature is out of range but it did not report a fault so you may have a bad connection or bad solder joint somewhere.
Did you do a good job of soldering on the header pins?
Otherwise the module is bad.
Not the ESP the MAX31865 module
yeah i also switched out the cloned board (pink)to a brand new adafruit board (blue)
that was the old cloned board:
The new sensor just arrived, but still doens't work. The good thing is that I now get a error code out of the serial monitor.
SM:
RTD value: 0
Ratio = 0.00000000
Resistance = 0.00000000
Temperature = -242.02
Fault 0x6C
RTD Low Threshold
REFIN- > 0.85 x Bias
RTDIN- < 0.85 x Bias - FORCE- open
Under/Over voltage
Could it be that i need pull up or pull down resistors betweeen the sdl and sda pins?
Grettings, Anabol
If I'm not mistaken, that blue wire at the far left should be at the far right.
You have it wired wrong
Connect the three wires to the three right-most contacts. The ones with the same color are to the right. In your case the blue ones.
Did you get it to worK?
Don't know where you are looking but I see two BLUE wires.
Hi, I am having the same issue with the RTD.
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Adafruit_MAX31865.h>
#include <PID_v1.h>
// Pin Definitions
#define RELAY_PIN 7
// RTD Sensor (PT100) - MAX31865 Setup
#define MAX31865_CS_PIN 10
Adafruit_MAX31865 thermo = Adafruit_MAX31865(MAX31865_CS_PIN, 11, 12, 13); // CS, DI, DO, CLK
// PID Variables
double setPoint = 60.0;
double inputTemp, outputTemp;
double Kp = 2.0, Ki = 0.0, Kd = 0.0;
PID myPID(&inputTemp, &outputTemp, &setPoint, Kp, Ki, Kd, DIRECT);
// LCD Display Setup (I2C)
LiquidCrystal_I2C lcd(0x27, 16, 2);
void setup() {
Serial.begin(9600);
pinMode(RELAY_PIN, OUTPUT);
digitalWrite(RELAY_PIN, LOW);
thermo.begin(MAX31865_3WIRE);
myPID.SetMode(AUTOMATIC);
myPID.SetOutputLimits(0, 255);
lcd.init();
lcd.backlight();
displayMessage("PID Control", "Initializing...");
delay(2000);
lcd.clear();
}
void loop() {
uint16_t rtd = thermo.readRTD();
Serial.print("Raw RTD: "); // Add this line
Serial.println(rtd); // Add this line
inputTemp = thermo.temperature(rtd, MAX31865_3WIRE);
printSerialData(inputTemp); // Just print the temperature
myPID.Compute();
controlHeatingElement(outputTemp);
displayTemperature();
delay(1000);
}
void printSerialData(double temp) {
Serial.print("Temperature: ");
Serial.println(temp);
Serial.print("PID Output: ");
Serial.println(outputTemp);
}
void controlHeatingElement(double output) {
analogWrite(RELAY_PIN, output); // PWM Control
}
void displayTemperature() {
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Set: ");
lcd.print(setPoint);
lcd.print("C");
lcd.setCursor(0, 1);
lcd.print("Temp: ");
lcd.print(inputTemp);
lcd.print("C");
}
void displayMessage(const char *line1, const char *line2) {
lcd.clear();
lcd.setCursor(0, 0);
lcd.print(line1);
lcd.setCursor(0, 1);
lcd.print(line2);
}
These are the results in my serial monitor.
Temperature: -242.01
PID Output: 255.00
Raw RTD: 7778
#include "Adafruit_MAX31865.h"
Adafruit_MAX31865 thermo = Adafruit_MAX31865(10, 11, 12, 13);
#define RREF 430.0
#define RNOMINAL 100.0
void setup() {
Serial.begin(9600);
thermo.begin(MAX31865_3WIRE); // 2WIRE, 3WIRE, 4WIRE
}
void loop() {
uint8_t fault = thermo.readFault();
if (fault) {
Serial.print("Fault 0x");
Serial.println(fault, HEX);
thermo.clearFault();
} else {
float temp = thermo.temperature(RNOMINAL, RREF);
Serial.print("Temp:");
Serial.println(temp);
}
}
When I plug in the code above, my results show ~5.5C inside an ice bath.
uint16_t rtd = thermo.readRTD();
Serial.print("Raw RTD: "); // Add this line
Serial.println(rtd); // Add this line
inputTemp = thermo.temperature(rtd, MAX31865_3WIRE);
Seems like the OP's code also has the above code. Could that be causing the issue he is describing that I am also experiencing?
@anabolicsurgeon not sure if you need the help, but i was able to figure out how to make it work. here is the code that I used to make it work.
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Adafruit_MAX31865.h>
#include <PID_v1.h>
// Pin Definitions
#define RELAY_PIN 7
// RTD Sensor (PT100) - MAX31865 Setup
Adafruit_MAX31865 thermo = Adafruit_MAX31865(10, 11, 12, 13);
// 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
// PID Variables
double setPoint = 60.0;
double inputTemp, outputTemp;
double Kp = 5.0, Ki = 0.0, Kd = 0.0;
PID myPID(&inputTemp, &outputTemp, &setPoint, Kp, Ki, Kd, DIRECT);
// LCD Display Setup (I2C)
LiquidCrystal_I2C lcd(0x27, 16, 2);
void setup() {
Serial.begin(9600);
pinMode(RELAY_PIN, OUTPUT);
digitalWrite(RELAY_PIN, LOW);
thermo.begin(MAX31865_3WIRE); // Initialize the sensor for 3-wire PT100
myPID.SetMode(AUTOMATIC);
myPID.SetOutputLimits(0, 255);
lcd.init();
lcd.backlight();
displayMessage("PID Control", "Initializing...");
delay(2000);
lcd.clear();
}
void loop() {
// Read the raw RTD resistance
uint16_t rtd = thermo.readRTD();
// Debugging the raw RTD resistance and ratio calculation
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);
// Now calculate the temperature from the RTD resistance
inputTemp = thermo.temperature(RNOMINAL, RREF); // PT100 sensor (nominal resistance: 100), Reference resistor: 430
Serial.print("Temperature = "); Serial.println(inputTemp);
// 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();
}
// Compute PID output based on the current temperature
myPID.Compute();
// Print PID data to Serial Monitor
printSerialData(inputTemp);
// Control Heating Element via Relay (PWM control)
controlHeatingElement(outputTemp);
// Display current temperature on the LCD
displayTemperature();
// Wait for a second
delay(1000);
}
// Function definitions
void displayMessage(const char* line1, const char* line2) {
lcd.clear();
lcd.setCursor(0, 0);
lcd.print(line1);
lcd.setCursor(0, 1);
lcd.print(line2);
}
void printSerialData(double temp) {
Serial.print("Temperature: ");
Serial.println(temp);
Serial.print("PID Output: ");
Serial.println(outputTemp);
}
void controlHeatingElement(double output) {
analogWrite(RELAY_PIN, output); // PWM Control
}
void displayTemperature() {
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Set: ");
lcd.print(setPoint);
lcd.print("C");
lcd.setCursor(0, 1);
lcd.print("Temp: ");
lcd.print(inputTemp);
lcd.print("C");
}
Hi,
Can I suggest you get that AC Mains to DC power supply AWAY from the input module.
Bad placement, AC-DC converter is a switching device, emitting EMR, your 31865 is a low level input signal device.
Not a good combination so close together.
Also place a 0.1uF capacitor across a RED/BLUE pair of terminals on the input to the 31865.
Tom.... 
