XIAOでMPL3115A2(気圧・高度・気温センサ)を使用する(CircuitPython版)

2020/7/2

CPY XIAO MPL115A2

CPY XIAO MPL115A2

概要

XIAOで以下のMPL3115A2(気圧・高度・気温センサ)を使用する(CircuitPython版)。 CircuitPythonのインストールについては「XIAOにCircuitPythonをインストールする」を参照のこと。 (ホストPCとしてはubuntuを想定している)

MPL115A2 - I2C Barometric Pressure/Temperature Sensor

接続

以下の接続でボードを接続する：

XIAO	MPL3115A2
3V3	Vin
GND	GND
SDA(D4)	SDA
SCL(D5)	SCL

The default I2C address is 0x60

外部ライブラリのインストール方法

  adafruitのアーカイブから以下のものを
  CIRCUITPY/libにコピーする：

  adafruit_mpl3115a2.mpy
  adafruit_bus_device(ディレクトリ)
  

デモ・プログラム

testmpl3115a2.py

  # Simple demo of the MPL3115A2 sensor.
  # Will read the pressure and temperature and print them out every second.
  # Author: Tony DiCola
  import time
  import board
  import busio
  import adafruit_mpl3115a2

  # Initialize the I2C bus.
  i2c = busio.I2C(board.SCL, board.SDA)

  # Initialize the MPL3115A2.
  sensor = adafruit_mpl3115a2.MPL3115A2(i2c)
  # Alternatively you can specify a different I2C address for the device:
  # sensor = adafruit_mpl3115a2.MPL3115A2(i2c, address=0x10)

  # You can configure the pressure at sealevel to get better altitude estimates.
  # This value has to be looked up from your local weather forecast or meteorlogical
  # reports.  It will change day by day and even hour by hour with weather
  # changes.  Remember altitude estimation from barometric pressure is not exact!
  # Set this to a value in pascals:
  sensor.sealevel_pressure = 102250

  # Main loop to read the sensor values and print them every second.
  while True:
      pressure = sensor.pressure
      print("Pressure: {0:0.3f} hPa".format(pressure/100))
      altitude = sensor.altitude
      print("Altitude: {0:0.3f} meters".format(altitude))
      temperature = sensor.temperature
      print("Temperature: {0:0.3f} degrees Celsius".format(temperature))
      print("");
      time.sleep(1.0)

  

出力例

picocom /dev/ttyACM0 -b115200

  ...
  <省略>
  ...


  Press any key to enter the REPL. Use CTRL-D to reload.
  Adafruit CircuitPython 5.3.0 on 2020-04-29; Seeeduino XIAO with samd21g18
  >>> import testmpl3115a2
  Pressure: 1001.597 hPa
  Altitude: 173.003 meters
  Temperature: 30.187 degrees Celsius

  Pressure: 1001.575 hPa
  Altitude: 172.753 meters
  Temperature: 30.187 degrees Celsius

  Pressure: 1001.632 hPa
  Altitude: 172.753 meters
  Temperature: 30.187 degrees Celsius

  Pressure: 1001.580 hPa
  Altitude: 173.128 meters
  Temperature: 30.187 degrees Celsius

  ...

  

参考情報

Seeeduino XIAO

XIAO Schematic
XIAO Pinout

Seeeduino XIAO Get Started By Nanase
コインサイズ Arduino互換機 Seeeduino XIAO を使ってみた

以上