HX710B Pressure Sensor Library

An Arduino library for interfacing with the MPS20N0040D pressure sensor using the HX710B ADC module. This library provides pressure measurements in multiple units with calibration features.

Features

• Multi-unit Support: Pressure readings in Pascal, kPa, PSI, mmHg, and ATM
• Advanced Calibration: Two-point linear calibration for improved accuracy
• Robust Communication: Interrupt-safe SPI communication with timeout handling
• Cross-platform: Compatible with Arduino, ESP32, ESP8266, and other platforms
• Power Management: Built-in power down/wake up functionality
• Ready Detection: Multiple methods for checking sensor readiness

Hardware Compatibility

• Pressure Sensor: MPS20N0040D (0-40 kPa range)
• ADC Module: HX710B
• Microcontrollers: Arduino Uno/Nano, ESP32, ESP8266, Teensy, and more

Installation

1. Download this library as a ZIP file
2. In Arduino IDE: Sketch → Include Library → Add .ZIP Library
3. Select the downloaded ZIP file

Quick Start

Basic Usage

#include "HX710B.h"

const int DOUT_Pin = 2;   // Sensor data pin
const int SCLK_Pin = 3;   // Sensor clock pin

HX710B pressure_sensor;

void setup() {
  Serial.begin(57600);
  pressure_sensor.begin(DOUT_Pin, SCLK_Pin);
}

void loop() {
  if (pressure_sensor.is_ready()) {
    Serial.print("Pressure: ");
    Serial.print(pressure_sensor.kPaCal());  // Calibrated reading
    Serial.println(" kPa");
  }
  delay(1000);
}

Available Pressure Units

float pascals = pressure_sensor.pascal();    // Pascals (Pa)
float kilopascals = pressure_sensor.kPaCal(); // Kilopascals (kPa) - calibrated
float psi = pressure_sensor.psi();           // Pounds per square inch
float mmHg = pressure_sensor.mmHg();         // Millimeters of mercury
float atm = pressure_sensor.atm();           // Atmospheres

Calibration

For accurate measurements, calibrate your sensor using the two-point method:

1. Zero Point: Record reading with sensor open to air
2. Reference Point: Apply known pressure (e.g., 10 kPa)
3. Calculate: Library computes linear calibration coefficients

See examples/HX710B_Calibration/ for a complete calibration example.

API Reference

Initialization

• begin(dout, pd_sck, gain) - Initialize sensor with pin assignments
• setGain(gain) - Set ADC gain (32, 64, or 128)

Reading Functions

• is_ready() - Check if sensor is ready for reading
• read() - Get single raw reading
• read_average(times) - Get averaged raw reading
• pascal(), kPaCal(), psi(), mmHg(), atm() - Pressure in various units

Calibration

• setCalibration(m, b) - Set linear calibration coefficients
• hasCalibration() - Check if calibration is set
• clearCalibration() - Remove calibration

Utility

• tare(times) - Set zero offset
• power_down() / power_up() - Power management
• wait_ready_timeout(ms) - Wait for sensor with timeout

Examples

• HX710B_Basic: Simple pressure reading example
• HX710B_Calibration: Complete calibration procedure with EEPROM storage

Wiring

HX710B Pin	Arduino Pin	Description
VCC	5V/3.3V	Power supply
GND	GND	Ground
DOUT	Digital Pin	Data output
SCLK	Digital Pin	Clock input

Troubleshooting

• "Sensor not found": Check wiring and power supply
• Inconsistent readings: Perform calibration
• Communication errors: Verify pin connections and try different pins

License

MIT License - see source files for details.

Author

R. Pelayo - roland@teachmemicro.com

Full Tutorial

For detailed setup instructions, wiring diagrams, and advanced usage examples, visit: https://www.teachmemicro.com/arduino-pressure-sensor-tutorial

Contributing

Issues and pull requests are welcome! Please check the GitHub repository for the latest updates and to report any problems.