README.md

Component: BH1750

This component will show you how to use I2C module read external i2c sensor data, here we use BH1750 light sensor(GY-30 module).
Pin assignment:
master: * GPIO18 is assigned as the data signal of i2c master port * GPIO19 is assigned as the clock signal of i2c master port
Connection:
- connect sda of sensor with GPIO18
- connect scl of sensor with GPIO19
- no need to add external pull-up resistors, driver will enable internal pull-up resistors.
Bh1750 measurement mode:
- one-time mode: bh1750 just measure only one time when receieved the one time measurement command, so you need to send this command when you want to get intensity value every time
- continuouly mode: bh1750 will measure continuouly when receieved the continuously measurement command, so you just need to send this command once, and than call iot_bh1750_get_data() to get intensity value repeatedly.
You can aslo call iot_bh1750_get_light_intensity() to get intensity value, the working process of this function is as followed:
- send measurement command
- delay longer than measurement time
- get intensity value

Bh1750 has different measurement time in different measurement mode, and also, measurement time can be changed by call iot_bh1750_change_measure_time()