# The MIT License (MIT)
#
# Copyright (c) 2017 Scott Shawcroft for Adafruit Industries.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
"""
`simpleio` - Simple, beginner friendly IO.
=================================================
The `simpleio` module contains classes to provide simple access to IO.
* Author(s): Scott Shawcroft
"""
import time
import sys
try:
import audioio
except ImportError:
pass # not always supported by every board!
import array
import digitalio
import pulseio
[docs]def tone(pin, frequency, duration=1, length=100):
"""
Generates a square wave of the specified frequency on a pin
:param ~microcontroller.Pin Pin: Pin on which to output the tone
:param float frequency: Frequency of tone in Hz
:param int length: Variable size buffer (optional)
:param int duration: Duration of tone in seconds (optional)
"""
if length * frequency > 350000:
length = 350000 // frequency
try:
# pin with PWM
with pulseio.PWMOut(pin, frequency=int(frequency), variable_frequency=False) as pwm:
pwm.duty_cycle = 0x8000
time.sleep(duration)
except ValueError:
# pin without PWM
sample_length = length
square_wave = array.array("H", [0] * sample_length)
for i in range(sample_length / 2):
square_wave[i] = 0xFFFF
if sys.implementation.version[0] >= 3:
square_wave_sample = audioio.RawSample(square_wave)
square_wave_sample.sample_rate = int(len(square_wave) * frequency)
with audioio.AudioOut(pin) as dac:
if not dac.playing:
dac.play(square_wave_sample, loop=True)
time.sleep(duration)
dac.stop()
else:
sample_tone = audioio.AudioOut(pin, square_wave)
sample_tone.frequency = int(len(square_wave) * frequency)
if not sample_tone.playing:
sample_tone.play(loop=True)
time.sleep(duration)
sample_tone.stop()
[docs]def bitWrite(x, n, b): #pylint: disable-msg=invalid-name
"""
Based on the Arduino bitWrite function, changes a specific bit of a value to 0 or 1.
The return value is the original value with the changed bit.
This function is written for use with 8-bit shift registers
:param x: numeric value
:param n: position to change starting with least-significant (right-most) bit as 0
:param b: value to write (0 or 1)
"""
if b == 1:
x |= 1<<n & 255
else:
x &= ~(1 << n) & 255
return x
[docs]def shift_in(data_pin, clock, msb_first=True):
"""
Shifts in a byte of data one bit at a time. Starts from either the LSB or
MSB.
.. warning:: Data and clock are swapped compared to other CircuitPython libraries
in order to match Arduino.
:param ~digitalio.DigitalInOut data_pin: pin on which to input each bit
:param ~digitalio.DigitalInOut clock: toggles to signal data_pin reads
:param bool msb_first: True when the first bit is most significant
:return: returns the value read
:rtype: int
"""
value = 0
i = 0
for i in range(0, 8):
if msb_first:
value |= ((data_pin.value) << (7-i))
else:
value |= ((data_pin.value) << i)
# toggle clock True/False
clock.value = True
clock.value = False
i += 1
return value
[docs]def shift_out(data_pin, clock, value, msb_first=True):
"""
Shifts out a byte of data one bit at a time. Data gets written to a data
pin. Then, the clock pulses hi then low
.. warning:: Data and clock are swapped compared to other CircuitPython libraries
in order to match Arduino.
:param ~digitalio.DigitalInOut data_pin: value bits get output on this pin
:param ~digitalio.DigitalInOut clock: toggled once the data pin is set
:param bool msb_first: True when the first bit is most significant
:param int value: byte to be shifted
Example for Metro M0 Express:
.. code-block:: python
import digitalio
import simpleio
from board import *
clock = digitalio.DigitalInOut(D12)
data_pin = digitalio.DigitalInOut(D11)
latchPin = digitalio.DigitalInOut(D10)
clock.direction = digitalio.Direction.OUTPUT
data_pin.direction = digitalio.Direction.OUTPUT
latchPin.direction = digitalio.Direction.OUTPUT
while True:
valueSend = 500
# shifting out least significant bits
# must toggle latchPin.value before and after shift_out to push to IC chip
# this sample code was tested using
latchPin.value = False
simpleio.shift_out(data_pin, clock, (valueSend>>8), msb_first = False)
latchPin.value = True
time.sleep(1.0)
latchPin.value = False
simpleio.shift_out(data_pin, clock, valueSend, msb_first = False)
latchPin.value = True
time.sleep(1.0)
# shifting out most significant bits
latchPin.value = False
simpleio.shift_out(data_pin, clock, (valueSend>>8))
latchPin.value = True
time.sleep(1.0)
latchpin.value = False
simpleio.shift_out(data_pin, clock, valueSend)
latchpin.value = True
time.sleep(1.0)
"""
value = value&0xFF
for i in range(0, 8):
if msb_first:
tmpval = bool(value & (1 << (7-i)))
data_pin.value = tmpval
else:
tmpval = bool((value & (1 << i)))
data_pin.value = tmpval
# toggle clock pin True/False
clock.value = True
clock.value = False
[docs]class DigitalOut:
"""
Simple digital output that is valid until reload.
:param pin microcontroller.Pin: output pin
:param value bool: default value
:param drive_mode digitalio.DriveMode: drive mode for the output
"""
def __init__(self, pin, **kwargs):
self.iopin = digitalio.DigitalInOut(pin)
self.iopin.switch_to_output(**kwargs)
@property
def value(self):
"""The digital logic level of the output pin."""
return self.iopin.value
@value.setter
def value(self, value):
self.iopin.value = value
[docs]class DigitalIn:
"""
Simple digital input that is valid until reload.
:param pin microcontroller.Pin: input pin
:param pull digitalio.Pull: pull configuration for the input
"""
def __init__(self, pin, **kwargs):
self.iopin = digitalio.DigitalInOut(pin)
self.iopin.switch_to_input(**kwargs)
@property
def value(self):
"""The digital logic level of the input pin."""
return self.iopin.value
@value.setter
def value(self, value): #pylint: disable-msg=no-self-use, unused-argument
raise AttributeError("Cannot set the value on a digital input.")
[docs]def map_range(x, in_min, in_max, out_min, out_max):
"""
Maps a number from one range to another.
Note: This implementation handles values < in_min differently than arduino's map function does.
:return: Returns value mapped to new range
:rtype: float
"""
mapped = (x-in_min) * (out_max - out_min) / (in_max-in_min) + out_min
if out_min <= out_max:
return max(min(mapped, out_max), out_min)
return min(max(mapped, out_max), out_min)