Turtorial Examples for CircuitPython(Teensy4.0)

2020/3/19

Turtorial Examples for CircuitPython(Teensy4.0)

Teensy4.0

Teensy4.0 pinout
Teensy4.0 Back Side pinout

How to install modules of Adafruit_CircuitPython_Bundle:

  mkdir cpy_ws
  cd cpy_ws

  git clone https://github.com/adafruit/Adafruit_CircuitPython_Bundle.git
  cd Adafruit_CircuitPython_Bundle
  ./update-submodules.sh 


  # sample case
  cd libraries/drivers
  cp /neopixel/neopixel.py  CIRCUTPY/lib/
  cd ..
  cd ..

  cd libraries/helpers 
  cp adafruit_bus_device CIRCUTPY/lib/
  cp adafruit_register CIRCUTPY/lib/


  

LED Blink

blink.py

  import board
  import digitalio
  import time

  led = digitalio.DigitalInOut(board.D13)
  led.direction = digitalio.Direction.OUTPUT

  while True:
      led.value = True
      time.sleep(0.1)
      led.value = False
      time.sleep(0.1)

  

Pin/GPIO

  # Teensy4.0
  import time
  import board
  from digitalio import DigitalInOut, Direction, Pull

  led = DigitalInOut(board.D13) # LED on board
  led.direction = Direction.OUTPUT

  switch = DigitalInOut(board.D2)  # switch on D2
  switch.direction = Direction.INPUT
  switch.pull = Pull.UP

  while True:
    led.value = not switch.value
    time.sleep(0.01)  # debounce delay

  

PWM

動作せず???

  import time
  import board
  import pulseio

  # D0 thru D9, D22, D23 for PWM (BackSide: D24,D25, D28,D29,D33 etc) 
  led = pulseio.PWMOut(board.D2, frequency=5000, duty_cycle=0)

  while True:
      for i in range(100):
          # PWM LED up and down
          if i < 50:
              led.duty_cycle = int(i * 2 * 65535 / 100)  # Up
          else:
              led.duty_cycle = 65535 - int((i - 50) * 2 * 65535 / 100)  # Down
          time.sleep(0.01)

  

ADC

  import time
  import board
  from analogio import AnalogIn

  knob = AnalogIn(board.A9)

  def get_voltage(raw):
      return (raw * 3.3) / 65536

  while True:
      raw = knob.value
      volts = get_voltage(raw)
      print("raw = {:5d} volts = {:5.2f}".format(raw, volts))
      time.sleep(0.5)

  

SPI

N.A.

I2C

  # software I2C
  import board
  import bitbangio
  i2c = bitbangio.I2C(board.D19, board.D18) # D19 -> SCL, D18 -> SDA
  i2c.try_lock()
  i2c.scan()

  >>> import board
  >>> import bitbangio
  >>> i2c = bitbangio.I2C(board.D19, board.D18)
  >>> i2c.try_lock()
  True
  >>> i2c.scan()
  [30]
  >>> 


  # hardware I2C
  import board
  import busio
  i2c = busio.I2C(board.SCL, board.SDA) # SCL -> D19, SDA -> D18
  i2c.try_lock()
  i2c.scan()

  >>> import board
  >>> import busio
  >>> i2c = busio.I2C(board.SCL, board.SDA)
  >>> i2c.try_lock()
  True
  >>> i2c.scan()
  [30]
  >>> 

  

RTC

clock.py

  # clock.py
  import time
  from time import sleep
  from rtc import RTC
  rtc = RTC()
  days = ("Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday")
  #                     year, mon, date, hour, min, sec, wday, yday, isdst
  t = time.struct_time((2020,  3,   17,  11,  42,  1,    2,   -1,    -1))
  rtc.datetime = t

  while True:
    dt = rtc.datetime
    print("date: {}/{}/{} {}".format(dt.tm_year, dt.tm_mon, dt.tm_mday, days[int(dt.tm_wday)]))
    print("time: {}:{:02}:{:02}".format(t.tm_hour, dt.tm_min, dt.tm_sec))
    print("---------------")
    sleep(1)

  

wday does not work at this version.

NeoPixel

module install:

# refer to https://github.com/adafruit/Adafruit_CircuitPython_Bundle

  mkdir cpy_ws
  cd cpy_ws

  git clone https://github.com/adafruit/Adafruit_CircuitPython_Bundle.git
  cd Adafruit_CircuitPython_Bundle
  ./update-submodules.sh 

  cd libraries/drivers/neopixel
  cp neopixel.py CIRCUTPY/lib/

  

Demo Script:

  import time
  import board
  import neopixel

  # connect D11 of Teensy4.0 to DIN of neopixels
  pixel_pin = board.D11

  # The number of NeoPixels
  num_pixels = 16

  # The order of the pixel colors - RGB or GRB. Some NeoPixels have red and green reversed!
  # For RGBW NeoPixels, simply change the ORDER to RGBW or GRBW.
  ORDER = neopixel.GRB

  pixels = neopixel.NeoPixel(pixel_pin, num_pixels, brightness=0.2, auto_write=False,
                             pixel_order=ORDER)

  def wheel(pos):
      # Input a value 0 to 255 to get a color value.
      # The colours are a transition r - g - b - back to r.
      if pos < 0 or pos > 255:
          r = g = b = 0
      elif pos < 85:
          r = int(pos * 3)
          g = int(255 - pos*3)
          b = 0
      elif pos < 170:
          pos -= 85
          r = int(255 - pos*3)
          g = 0
          b = int(pos*3)
      else:
          pos -= 170
          r = 0
          g = int(pos*3)
          b = int(255 - pos*3)
      return (r, g, b) if ORDER == neopixel.RGB or ORDER == neopixel.GRB else (r, g, b, 0)


  def rainbow_cycle(wait):
      for j in range(255):
          for i in range(num_pixels):
              pixel_index = (i * 256 // num_pixels) + j
              pixels[i] = wheel(pixel_index & 255)
          pixels.show()
          time.sleep(wait)

  while True:
      pixels.fill((255, 0, 0))
      pixels.show()
      time.sleep(0.5)

      pixels.fill((0, 255, 0))
      pixels.show()
      time.sleep(0.5)

      pixels.fill((0, 0, 255))
      pixels.show()
      time.sleep(0.5)

      rainbow_cycle(0.001)    # rainbow cycle with 1ms delay per step

  

第１番目のLEDは指定通りの色で光らないバグがあるようだ。 (ハード起因かソフト起因は不明)

DHT

以下、動作せず。 DHTのVCCとして5Vが必要？？

  import time
  import board
  import adafruit_dht

  # Initial the dht device, with data pin connected to:
  dht = adafruit_dht.DHT11(board.D12)

  while True:
      try:
          # Print the values to the serial port
          temperature_c = dht.temperature
          temperature_f = temperature_c * (9 / 5) + 32
          humidity = dht.humidity
          print("Temp: {:.1f} F / {:.1f} C    Humidity: {}% "
                .format(temperature_f, temperature_c, humidity))

      except RuntimeError as error:
          # Errors happen fairly often, DHT's are hard to read, just keep going
          print(error.args[0])

      time.sleep(2.0)

  

Networking

N.A.

Performance Test

performanceCircuitPython.py

  # Peformace Test CircuitPython
  from time import monotonic_ns
  def performanceTest():
      endTime = monotonic_ns() + 10000000000 # 10 sec
      count = 0
      while monotonic_ns() < endTime:
          count += 1
      print("Count: ", count)

  performanceTest()

  

出力例：
Count: 476009

monotonic_nsのオーバーヘッドが大きいようなので、 それを使わず、実行後、１０秒後、Ctrl-Cを押して止めて、countの内容を確認するバージョンも作った：

  # Manual Stop version
  # Peformace Test CircuitPython
  from time import monotonic_ns
  def performanceTest():
      global count
      while True:
          count += 1
      print("Count: ", count)

  count = 0
  performanceTest()
  

出力例：
>>> count
1387524

monotonic_ns無しのほうが３倍くらい速い。
（Nucleo-F446REよりは遅い）

関連情報

Teensy4.0にCircuitPythonをインストールする
MicroPython Performance Test

以上