ماژول مبدل دمای آنالوگ به دیجیتال MAX31865

MAX31865 PT100 platinum resistance temperature detector
What is the MAX31865
The MAX31865 module is an amplifier that is designed to read temperature measurements from PT100 or PT1000 type sensors, also known as platinum resistance temperature detectors (RTD).
How does the MAX31865 work
The module is responsible for reading the resistance of the PT100 sensor and converting this analog signal into digital data to be interpreted by a microcontroller.
The MAX31865 chip has a precision delta-sigma converter with a 15-bit resolution, equivalent to 0.03125ºC.
The communication protocol is SPI type, so it can easily work with Arduino, Microcomputers such as Raspberry or PIC.
TECHNICAL SPECIFICATIONS
Operating voltage: 3.3V to 5V
Resolution: 15 bits (0.03125ºC)
Accuracy: 0.5ºC
Conversion time: 21ms (max.)
Input protection: ± 45 V
Communication: SPI Protocol
Supported RTD: PT100, PT1000
No. of Threads: 2, 3, 4
Has holes for mounting
PCB color may vary (Purple, Black)
Dimensions: 28 x 25.3 x 3 mm

Datasheet: MAX31865

How to configure the MAX31865?
The MAX31865 module can be configured to work with 2, 3, or 4-wire PT100 or PT1000 sensors.
The default setting is for 4-wire sensors.
To use 3-wire sensors the following modifications must be made: solder the pads labeled “2/3 Wire”, cut the jumper between pads “24” and finally solder the center pad to pad “3”.
To use 2-wire sensors you must solder the pads labeled “2/3 Wire” and “2 Wire”.
Test Code
Below we present the following code so you can recreate it in the Arduino IDE, compile it and upload it to your ESP32, you can also use an Arduino but you must make the change in the pin connection, once loaded you will be able to see on the serial screen how the temperature that the sensor is recording is displayed.
This is a simple code but it can give you an idea of ​​how it works or how the code should be in order to carry out a larger project.
Remember that you will need the library to run the MAX31865, you can find it Here!

#include <Adafruit_MAX31865.h>
 // SPI protocol: CS, DI, DO, CLK 
Adafruit_MAX31865 thermo = Adafruit_MAX31865(5, 2, 3, 4); //////////////Variables Temperature sensor #define RREF 430.0 //defined by max #define RNOMINAL 100.0 //defined by max void setup () {
  Serial.begin (115200); //Define baudrate Serial.println ( "MAX and PT100 test" ); thermo.begin 
  ( MAX31865_2WIRE);   // Set the amount of wires 2Wire or 3Wire or 4Wire 
} void loop (){
   Serial. print ( "Temperature" );
  Serial. println (Read_temperature());
   delay (1000); 
} //// Sensor reading float Read_temperature (){
    uint16_t rtd = thermo. readRTD();
     float ratio = rtd; 
  ratio = 32768; return (thermo. temperature(RNOMINAL, RREF)); 
}