I2C

The following example receives data from a light sensor using I2C. The sensor used is the BH1750FVI Digital Light Sensor.

Note

For F1 module and F1 Starter Kit, I2C(0) is reserved for internal use. Please start from I2C(1) for any new I2C bus.

import time
from machine import I2C
import bh1750fvi

i2c = I2C(1, freq=100000)
# Remark: I2C(0) is reserved in F1 as internal I2C bus
light_sensor = bh1750fvi.BH1750FVI(i2c, addr=i2c.scan()[0])

while True:
    data = light_sensor.read()
    print(data)
    time.sleep(1)

Drivers for the BH1750FVI

Place this code into a file named bh1750fvi.py. This can then be imported as a library.

# Simple driver for the BH1750FVI digital light sensor

class BH1750FVI:
    MEASUREMENT_TIME = const(120)

    def __init__(self, i2c, addr=0x23, period=150):
        self.i2c = i2c
        self.period = period
        self.addr = addr
        self.time = 0
        self.value = 0
        self.i2c.writeto(addr, bytes([0x10]))  # start continuous 1 Lux readings

    def read(self):
        self.time += self.period
        if self.time >= MEASUREMENT_TIME:
            self.time = 0
            data = self.i2c.readfrom(self.addr, 2)
            self.value = (((data[0] << 8) + data[1]) * 1200) // 1000
        return self.value