The BH1750 is a digital light sensor designed to measure ambient light intensity in lux, providing precise and reliable readings. It communicates via the I2C protocol, making it easy to integrate into microcontroller-based systems. The sensor is widely used in applications such as automatic brightness control for displays, energy-efficient lighting systems, and environmental monitoring.
Key features of the BH1750 include high resolution (up to 1 lux), low power consumption, and a compact design, making it suitable for portable and battery-powered devices.
This circuit is a Bluetooth-enabled audio system powered by a rechargeable 18650 Li-ion battery. It includes a TP4056 module for battery charging and protection, a PAM8403 amplifier with volume control to drive two loudspeakers, and a Bluetooth audio receiver to wirelessly receive audio signals.
Open Project in Cirkit Designer
This circuit features an ESP32 microcontroller interfaced with a BH1750 light sensor, a DHT22 temperature and humidity sensor, and two LD2410C radar sensors. The ESP32 collects environmental data from the sensors and can communicate with the radar sensors via UART for motion detection.
Open Project in Cirkit Designer
This circuit features an Arduino Mega ADK as the central microcontroller, interfacing with a variety of sensors and actuators. It includes a BH1750 light sensor and a DHT11 temperature and humidity sensor for environmental monitoring, both interfacing via I2C. The system controls a stepper motor via an A4988 driver, two water pumps through a 3-channel relay, and a fan using an IRF520 PWM module, with several push switches to trigger inputs. An OLED display provides a user interface, and soil moisture levels are monitored with two soil sensors. A non-contact water level sensor is also included for liquid level detection.
Open Project in Cirkit Designer
This circuit uses an Arduino UNO to interface with a BH1750 light sensor via I2C communication. The Arduino reads light intensity data from the BH1750 sensor, which is powered by the Arduino's 3.3V and GND pins.
Open Project in Cirkit DesignerThe following table outlines the key technical details of the BH1750:
| Parameter | Value |
|---|---|
| Operating Voltage | 2.4V to 3.6V |
| Operating Current | 0.12 mA (typical) |
| Measurement Range | 1 lux to 65535 lux |
| Communication Protocol | I2C (7-bit address: 0x23 or 0x5C) |
| Resolution | 1 lux |
| Operating Temperature | -40°C to +85°C |
| Dimensions | 3.0mm x 1.6mm x 1.2mm |
The BH1750 has six pins, as described in the table below:
| Pin Number | Pin Name | Description |
|---|---|---|
| 1 | VCC | Power supply (2.4V to 3.6V) |
| 2 | GND | Ground |
| 3 | SDA | I2C data line |
| 4 | SCL | I2C clock line |
| 5 | ADDR | I2C address selection (LOW: 0x23, HIGH: 0x5C) |
| 6 | NC | Not connected (leave unconnected or floating) |
Below is an example of how to use the BH1750 with an Arduino UNO:
#include <Wire.h>
#include <BH1750.h>
// Create an instance of the BH1750 library
BH1750 lightMeter;
void setup() {
Serial.begin(9600); // Initialize serial communication at 9600 baud
Wire.begin(); // Initialize I2C communication
// Initialize the BH1750 sensor
if (lightMeter.begin(BH1750::CONTINUOUS_HIGH_RES_MODE)) {
Serial.println("BH1750 initialized successfully");
} else {
Serial.println("Error initializing BH1750. Check connections.");
while (1); // Halt execution if initialization fails
}
}
void loop() {
// Read light intensity in lux
float lux = lightMeter.readLightLevel();
// Print the light intensity to the Serial Monitor
Serial.print("Light Intensity: ");
Serial.print(lux);
Serial.println(" lux");
delay(1000); // Wait for 1 second before taking the next reading
}
No Data from the Sensor
Inaccurate Readings
Sensor Not Initializing
Q: Can the BH1750 operate at 5V?
A: No, the BH1750 operates at a voltage range of 2.4V to 3.6V. Use a level shifter if interfacing with a 5V system.
Q: How do I change the measurement mode?
A: The BH1750 library allows you to set different modes (e.g., high resolution, low resolution) using the begin() function. Refer to the library documentation for details.
Q: What is the maximum distance for I2C communication?
A: The maximum distance depends on the pull-up resistor values and the I2C clock speed. For typical setups, keep the distance under 1 meter for reliable communication.