BH1750 light sensor (GY-30): specs and pinout
Breakout module built around the ROHM BH1750FVI digital ambient light sensor IC, which reads light level over I2C. Facts below are for the BH1750FVI chip; the GY-30 board itself is not covered by an official document.
Specs
| Spec | Value | Source |
|---|---|---|
| Supply voltage VCC (chip) | 2.4 V to 3.6 V (typ 3.0 V) | source Operating Conditions, p.1 |
| Absolute maximum supply voltage (chip) | 4.5 V | source Absolute Maximum Ratings, p.1 |
| I2C reference voltage DVI (chip) | 1.65 V to VCC | source Operating Conditions, p.1 |
| Interface | I2C bus, f/s mode; SCL up to 400 kHz | source Features p.1; Electrical Characteristics p.2 |
| I2C slave address | ADDR = L: 0100011 (0x23); ADDR = H: 1011100 (0x5C) | source Slave Address section (hex values converted from the binary addresses) |
| Measurement range | 1 to 65535 lx | source Descriptions and Features, p.1 |
| Resolution | H-resolution mode 1 lx; H-resolution mode2 0.5 lx; L-resolution mode 4 lx | source Electrical Characteristics p.2; instruction set table |
| Measurement time | H-resolution typ 120 ms, max 180 ms; L-resolution typ 16 ms, max 24 ms | source Electrical Characteristics, p.2 |
| Supply current | typ 120 uA, max 190 uA (VCC = 3.0 V, 100 lx); power-down typ 0.01 uA, max 1.0 uA | source Electrical Characteristics, p.2 |
| Operating temperature (chip) | -40 C to 85 C | source Absolute Maximum Ratings, p.1 |
| Measurement variation | +/- 20 % | source Features item 12, p.1 |
Power
| Value | Source | |
|---|---|---|
| Supply | Chip: 2.4 V to 3.6 V; the GY-30 board's regulator and input range are not documented by an official source | source Operating Conditions p.1; Electrical Characteristics p.2 |
| Current | 120 uA typical (chip, VCC 3.0 V, 100 lx) | source Operating Conditions p.1; Electrical Characteristics p.2 |
Chip pins
These are the pins of the chip on the module, from the chip datasheet. The module's own header may label or expose them differently.
Chip-only pinout: the six rows are the BH1750FVI IC package pins, not the GY-30 header order. The GY-30 module board (regulator, pull-ups, header order, 5 V tolerance) is not covered by an official document.
| Pin | Function | Voltage | Notes | Source |
|---|---|---|---|---|
| 1: VCC | Power supply terminal | BH1750FVI chip package pin, not the GY-30 header order | source Terminal Description, p.13 | |
| 2: ADDR | I2C slave-address terminal; H (>= 0.7 VCC) = 1011100, L (<= 0.3 VCC) = 0100011 | BH1750FVI chip package pin, not the GY-30 header order | source Terminal Description, p.13 | |
| 3: GND | GND terminal | BH1750FVI chip package pin, not the GY-30 header order | source Terminal Description, p.13 | |
| 4: SDA | I2C bus interface SDA terminal | BH1750FVI chip package pin, not the GY-30 header order | source Terminal Description, p.13 | |
| 5: DVI | SDA, SCL reference voltage terminal and asynchronous reset for internal registers | BH1750FVI chip package pin, not the GY-30 header order | source Terminal Description, p.13 | |
| 6: SCL | I2C bus interface SCL terminal | BH1750FVI chip package pin, not the GY-30 header order | source Terminal Description, p.13 |
Build with it
Project ideas for the BH1750 light sensor (GY-30). Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.
- Pocket lux meter: Both parts are I2C on separate addresses. Power the sensor module from the 3.3 V pin, inside the chip's 2.4-3.6 V range.
- Automatic night light: The BH1750 reports lux digitally over I2C, so no analog input is needed. The LED is driven from a GPIO through a series resistor. Learning project.
- Room light logger: The Zero W header exposes I2C on pins 3 (SDA1) and 5 (SCL1) and a 3V3 pin 1 (official schematic), matching the sensor's 2.4-3.6 V supply and I2C interface.
- Light-level desk monitor: Both are I2C devices with different addresses on one bus, run from the ESP32 3.3 V. The module supply for the OLED is not documented here, so check its markings. Learning project.
Common mistakes
- Supplying the bare chip above its range: operating VCC is 2.4 V to 3.6 V and absolute maximum is 4.5 V; the GY-30 board is not documented here, so power it from a 3.3 V pin (source: link, p.1)
- Sending two commands in one transfer: the sensor cannot accept plural commands without a stop condition, so end every opcode with a stop (source: link, I2C interface section)
- Using the Reset command in power-down mode: it is not accepted there; it only clears the illuminance data register (source: link, instruction set table)
Not covered by the official source
- Values are from the ROHM BH1750FVI datasheet (copy hosted by DigiKey).
- Module (GY-30) facts are not sourced: on-board regulator, pull-up resistors, 5 V tolerance, header order and labels are not given.
- Page numbers are those printed in the PDF footer; rows without a page number come from the instruction set and I2C interface sections.
Sources
- link (ROHM BH1750FVI Technical Note No.11046EDT01, Rev.D 2011.11, 17 pp)