# I2C

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

```python
import time
from machine import I2C
import bh1750fvi

i2c = I2C(0, I2C.MASTER, baudrate=100000)
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 sample code into a file named `bh1750fvi.py`. This can then be imported as a library.

```python
# 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 continuos 1 Lux readings every 120ms

    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
```

## Light sensor and LoRa

This is the same code, with added LoRa connectivity, sending the lux value from the light sensor to another LoRa enabled device.

```python
import socket
import time
import pycom
import struct
from network import LoRa
from machine import I2C
import bh1750fvi

LORA_PKG_FORMAT = "!BH"
LORA_CONFIRM_FORMAT = "!BB"

DEVICE_ID = 1

pycom.heartbeat(False)

lora = LoRa(mode=LoRa.LORA, tx_iq=True, region=LoRa.EU868)
lora_sock = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
lora_sock.setblocking(False)

i2c = I2C(0, I2C.MASTER, baudrate=100000)
light_sensor = bh1750fvi.BH1750FVI(i2c, addr=i2c.scan()[0])

while(True):
    msg = struct.pack(LORA_PKG_FORMAT, DEVICE_ID, light_sensor.read())
    lora_sock.send(msg)

    pycom.rgbled(0x150000)

    wait = 5
    while (wait > 0):
        wait = wait - 0.1
        time.sleep(0.1)
        recv_data = lora_sock.recv(64)

        if (len (recv_data) >= 2):
            status, device_id = struct.unpack(LORA_CONFIRM_FORMAT, recv_data)

            if (device_id == DEVICE_ID and status == 200):
                pycom.rgbled(0x001500)
                wait = 0

    time.sleep(1)
```