nodemcu-firmware/docs/lua-modules/bh1750.md

BH1750 Module

Since	Origin / Contributor	Maintainer	Source
2015-01-30	Martin Han	Martin Han	bh1750.lua

This Lua module provides access to BH1750 I²C ambient light sensor.

!!! note This module requires i2c C module built into firmware.

Require

bh1750 = require("bh1750")

Release

bh1750 = nil
package.loaded["bh1750"] = nil

bh1750.init()

Initializes the module and sets up I²C with hardcoded device address.

Syntax

bh1750.init(sda, scl)

Parameters

• sda SDA pin number.
• scl SCL pin number.

Returns

nil

bh1750.read()

Reads lux value from the sensor.

Syntax

bh1750.read()

Parameters

None

Returns

Lux value.

bh1750.getlux()

Function used to return last read lux value.

Syntax

bh1750.getlux()

Parameters

None

Returns

Last known lux value.

Example

SDA_PIN = 6 -- sda pin, GPIO12
SCL_PIN = 5 -- scl pin, GPIO14

bh1750 = require("bh1750")
bh1750.init(SDA_PIN, SCL_PIN)
bh1750.read()
l = bh1750.getlux()
print("lux: "..(l / 100).."."..(l % 100).." lx")

-- release module
bh1750 = nil
package.loaded["bh1750"] = nil