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95 lines
2.3 KiB
Markdown
95 lines
2.3 KiB
Markdown
# I2C
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The following example receives data from a light sensor using I2C. Sensor used is the BH1750FVI Digital Light Sensor.
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```python
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import time
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from machine import I2C
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import bh1750fvi
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i2c = I2C(0, I2C.MASTER, baudrate=100000)
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light_sensor = bh1750fvi.BH1750FVI(i2c, addr=i2c.scan()[0])
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while(True):
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data = light_sensor.read()
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print(data)
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time.sleep(1)
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```
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## Drivers for the BH1750FVI
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Place this sample code into a file named `bh1750fvi.py`. This can then be imported as a library.
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```python
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# Simple driver for the BH1750FVI digital light sensor
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class BH1750FVI:
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MEASUREMENT_TIME = const(120)
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def __init__(self, i2c, addr=0x23, period=150):
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self.i2c = i2c
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self.period = period
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self.addr = addr
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self.time = 0
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self.value = 0
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self.i2c.writeto(addr, bytes([0x10])) # start continuos 1 Lux readings every 120ms
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def read(self):
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self.time += self.period
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if self.time >= MEASUREMENT_TIME:
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self.time = 0
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data = self.i2c.readfrom(self.addr, 2)
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self.value = (((data[0] << 8) + data[1]) * 1200) // 1000
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return self.value
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```
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## Light sensor and LoRa
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This is the same code, with added LoRa connectivity, sending the lux value from the light sensor to another LoRa enabled device.
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```python
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import socket
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import time
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import pycom
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import struct
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from network import LoRa
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from machine import I2C
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import bh1750fvi
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LORA_PKG_FORMAT = "!BH"
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LORA_CONFIRM_FORMAT = "!BB"
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DEVICE_ID = 1
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pycom.heartbeat(False)
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lora = LoRa(mode=LoRa.LORA, tx_iq=True, region=LoRa.EU868)
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lora_sock = socket.socket(socket.AF_LORA, socket.SOCK_RAW)
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lora_sock.setblocking(False)
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i2c = I2C(0, I2C.MASTER, baudrate=100000)
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light_sensor = bh1750fvi.BH1750FVI(i2c, addr=i2c.scan()[0])
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while(True):
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msg = struct.pack(LORA_PKG_FORMAT, DEVICE_ID, light_sensor.read())
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lora_sock.send(msg)
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pycom.rgbled(0x150000)
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wait = 5
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while (wait > 0):
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wait = wait - 0.1
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time.sleep(0.1)
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recv_data = lora_sock.recv(64)
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if (len (recv_data) >= 2):
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status, device_id = struct.unpack(LORA_CONFIRM_FORMAT, recv_data)
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if (device_id == DEVICE_ID and status == 200):
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pycom.rgbled(0x001500)
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wait = 0
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time.sleep(1)
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```
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