ESP32 BMP388 / CJMCU-388 Barometric Pressure Sensor

🛠️ BMP388 / CJMCU-388 Barometric Pressure Sensor Troubleshooting

This guide outlines a systematic approach to troubleshoot and resolve common problems with the . Start by confirming that the hardware connections are correct, as wiring mistakes are the most frequent cause of issues. If you are sure the connections are correct, follow the below steps to debug common issues.

💻 Library Not Found Error

❌ Sensor Initialization Failure

⚠️ Incorrect Pressure Readings

💻 Code Examples

Below you can find code examples of BMP388 / CJMCU-388 Barometric Pressure Sensor with ESP32 in several frameworks:

• Arduino IDE
• ESP-IDF
• ESPHome
• PlatformIO

If you encounter issues while using the BMP388 / CJMCU-388 Barometric Pressure Sensor, check the Common Issues Troubleshooting Guide.

ESP32 BMP388 Arduino IDE Code Example

Example in Arduino IDE

Fill in your main Arduino IDE sketch file with the following code to use the BMP388 / CJMCU-388 Barometric Pressure Sensor:

#include <Wire.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BMP3XX.h>

Adafruit_BMP3XX bmp;

void setup() {
  Serial.begin(115200);
  if (!bmp.begin(0x76)) {
    Serial.println("Could not find a valid BMP388 sensor, check wiring!");
    while (1);
  }
}

void loop() {
  Serial.print("Temperature: ");
  Serial.print(bmp.temperature);
  Serial.println(" *C");

  Serial.print("Pressure: ");
  Serial.print(bmp.pressure / 100.0);
  Serial.println(" hPa");
  delay(2000);
}

This Arduino code initializes the BMP388 sensor using the Adafruit BMP3XX library. It reads temperature and pressure values and prints them to the Serial Monitor every two seconds.

Connect your ESP32 to your computer via a USB cable, Ensure the correct Board and Port are selected under Tools, Click the "Upload" button in the Arduino IDE to compile and upload the code to your ESP32.

ESP32 BMP388 ESP-IDF Code Example

Example in Espressif IoT Framework (ESP-IDF)

If you're using ESP-IDF to work with the BMP388 / CJMCU-388 Barometric Pressure Sensor, here's how you can set it up and read data from the sensor. Fill in this code in the main ESP-IDF file:

#include "bmp388.h"
#include "esp_log.h"

#define I2C_MASTER_SCL_IO 22
#define I2C_MASTER_SDA_IO 21
#define I2C_MASTER_FREQ_HZ 100000
#define BMP388_ADDR 0x76

static const char *TAG = "BMP388";

void app_main() {
    ESP_LOGI(TAG, "Initializing BMP388...");
    bmp388_dev dev;
    bmp388_init(&dev, I2C_MASTER_SCL_IO, I2C_MASTER_SDA_IO, I2C_MASTER_FREQ_HZ, BMP388_ADDR);

    while (1) {
        bmp388_data data;
        bmp388_read(&dev, &data);
        ESP_LOGI(TAG, "Temperature: %.2f°C", data.temperature);
        ESP_LOGI(TAG, "Pressure: %.2f hPa", data.pressure);
        vTaskDelay(2000 / portTICK_PERIOD_MS);
    }
}

This ESP-IDF code configures the ESP32 to interface with the BMP388 sensor over I²C. The bmp388_init function initializes the sensor, and bmp388_read fetches pressure and temperature readings.

Update the I2C pins (I2C_MASTER_SDA_IO and I2C_MASTER_SCL_IO) to match your ESP32 hardware setup, Use idf.py build to compile the project, Use idf.py flash to upload the code to your ESP32.

ESP32 BMP388 ESPHome Code Example

Example in ESPHome (Home Assistant)

Fill in this configuration in your ESPHome YAML configuration file (example.yml) to integrate the BMP388 / CJMCU-388 Barometric Pressure Sensor

sensor:
  - platform: bmp388
    temperature:
      name: "BMP388 Temperature"
    pressure:
      name: "BMP388 Pressure"
    address: 0x76

This ESPHome configuration enables the BMP388 sensor to provide temperature and pressure readings over I²C, using the default address 0x76.

Upload this code to your ESP32 using the ESPHome dashboard or the esphome run command.

ESP32 BMP388 PlatformIO Code Example

Example in PlatformIO Framework

For PlatformIO, make sure to configure the platformio.ini file with the appropriate environment and libraries, and then proceed with the code.

Configure platformio.ini

First, your platformio.ini should look like below. You might need to include some libraries as shown. Make sure to change the board to your ESP32:

[env:esp32dev]
platform = espressif32
board = esp32dev
framework = arduino
lib_deps = 
    adafruit/Adafruit BMP3XX Library
    wire
monitor_speed = 115200

ESP32 BMP388 PlatformIO Example Code

Write this code in your PlatformIO project under the src/main.cpp file to use the BMP388 / CJMCU-388 Barometric Pressure Sensor:

#include <Wire.h>
#include <Adafruit_BMP3XX.h>

Adafruit_BMP3XX bmp;

void setup() {
  Serial.begin(115200);
  if (!bmp.begin(0x76)) {
    Serial.println("Could not find a valid BMP388 sensor, check wiring!");
    while (1);
  }
}

void loop() {
  Serial.print("Temperature: ");
  Serial.print(bmp.temperature);
  Serial.println(" *C");

  Serial.print("Pressure: ");
  Serial.print(bmp.pressure / 100.0);
  Serial.println(" hPa");
  delay(2000);
}

This PlatformIO code integrates the BMP388 sensor to read temperature and pressure values, printing them every two seconds.

Upload the code to your ESP32 using the PlatformIO "Upload" button in your IDE or the pio run --target upload command.