AtlasStampI2C

Arduino library to talk to Atlas Scientific EZO Stamp modules in I2C mode (PH, DO, ORP, EC).

It wraps the EZO I2C command protocol behind a small class hierarchy, one class per sensor type, and offers both synchronous and asynchronous reads, temperature / pressure / salinity compensation, and sleep / wakeup control.

Legacy library (2019). Kept for reference; docs refreshed in 2026, library behavior unchanged.

Features

• One class per module: AtlasStampPh, AtlasStampDo, AtlasStampOrp, AtlasStampEc.
• Synchronous read (read()) and non-blocking asynchronous read (read_async() / available() / result_async()).
• Results as float* or as a C string (read_ascii() / result_ascii_async()).
• Temperature compensation (PH, DO, EC), plus pressure / salinity (DO) and K / output parameters (EC).
• Sleep / wakeup, on-board LED control and supply voltage readout (get_vcc()).

Installation

• Manual: copy this folder into your Arduino libraries/ directory and restart the IDE.
• PlatformIO: add the repository to lib_deps.

This library uses the standard Wire (I2C) library; call Wire.begin() before using the sensors.

Synchronous example

#include <Wire.h>
#include "AtlasStampPH.h"

#define PH_SENSOR_ADDRESS 0x63

AtlasStampPh PHSensor(PH_SENSOR_ADDRESS);

void setup() {
  Serial.begin(115200);
  Wire.begin();

  if (!PHSensor.begin()) {
    Serial.println("ERROR, PH sensor not present or failed to initialize");
  }

  PHSensor.info(Serial);
  Serial.println();
}

void loop() {
  float* reading = PHSensor.read();
  if (reading != nullptr) {
    Serial.print("PH: ");
    Serial.print(*reading);
    Serial.print(" ");
    Serial.println(PHSensor.get_unit());
  }
  delay(1000);
}

Asynchronous example

read_async() starts a reading without blocking. Do other work, then check available() and pull the value with result_async(). An invalid reading is reported as -2048.0f.

#include <Wire.h>
#include "AtlasStampPH.h"

#define PH_SENSOR_ADDRESS 0x63

AtlasStampPh PHSensor(PH_SENSOR_ADDRESS);

void setup() {
  Serial.begin(115200);
  Wire.begin();

  if (!PHSensor.begin()) {
    Serial.println("ERROR, PH sensor not present or failed to initialize");
  }
}

void loop() {
  // Start a reading if the sensor is idle.
  PHSensor.read_async();

  // ... do other work here while the module takes the reading ...

  if (PHSensor.available()) {
    float* reading = PHSensor.result_async();
    if (reading != nullptr && *reading != -2048.0f) {
      Serial.print("PH: ");
      Serial.println(*reading);
    } else {
      Serial.println("Invalid result from Atlas module");
    }
  }
}

See examples/PHReading for a complete sketch.

API overview

Common to all modules (from AtlasStamp):

bool   begin();              // detect and initialize the module
float* read();               // blocking read, nullptr on failure
bool   read_async();         // start a non-blocking read
bool   available();          // true when an async result is ready
float* result_async();       // fetch the async result
uint8_t read_ascii(char*);          // blocking read as C string
uint8_t result_ascii_async(char*);  // async result as C string
uint8_t address();
bool    ready();
bool    busy();
char*   get_unit();
float   get_min_value();
float   get_max_value();
float   get_vcc();
bool    led();  bool led(bool);
bool    sleep();  bool wakeup();  bool sleeping();
void    info(Stream&);

Temperature-compensated modules (AtlasStampPh, AtlasStampDo, AtlasStampEc):

bool  set_temperature(float);
bool  set_temperature(float value, float max_divergence);
float get_temperature();

DO-specific (AtlasStampDo): set_pressure(), get_pressure(), set_salinity(), get_salinity().

EC-specific (AtlasStampEc): set_k(), get_k(), set_output_parameter(), get_output_parameter() (output parameters EC, TDS, S, SG).

License

MIT © 2019–2026 mdps

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Un proyecto de mdps · 2026 · desarrollado en Murcia.