WallE/control/pca9685/pca9685.py

#!/usr/bin/python
'''
**********************************************************************
* Filename    : PCA9685.py
* Description : A driver module for PCA9685
* Author      : Cavon
* Brand       : SunFounder
* E-mail      : service@sunfounder.com
* Website     : www.sunfounder.com
* Version     : v2.0.0
**********************************************************************
'''

from smbus2 import SMBus
import time
import math
import os


MOCK_ENV = 'PCA9685_MOCK_SMBUS'


class MockSMBus:
    def __init__(self, bus_number):
        self.bus_number = bus_number
        self.data = {}

    def write_byte_data(self, addr, res, value):
        print(f"SMBus write {addr}[{res}] {value}")
        if addr not in self.data:
            self.data[addr] = {}
        self.data[addr][res] = value if value else 0

    def read_byte_data(self, addr, res):
        print(f"SMBus read {addr}[{res}]")
        if addr not in self.data:
            self.data[addr] = {}
        return self.data[addr][res] if res in self.data[addr] else 0


def map_range(x, in_min, in_max, out_min, out_max):
    """To map the value from arange to another"""
    return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min


class PWM:
    """A PWM control class for PCA9685."""
    _MODE1 = 0x00
    _MODE2 = 0x01
    _SUBADR1 = 0x02
    _SUBADR2 = 0x03
    _SUBADR3 = 0x04
    _PRESCALE = 0xFE
    _LED0_ON_L = 0x06
    _LED0_ON_H = 0x07
    _LED0_OFF_L = 0x08
    _LED0_OFF_H = 0x09
    _ALL_LED_ON_L = 0xFA
    _ALL_LED_ON_H = 0xFB
    _ALL_LED_OFF_L = 0xFC
    _ALL_LED_OFF_H = 0xFD

    _RESTART = 0x80
    _SLEEP = 0x10
    _ALLCALL = 0x01
    _INVRT = 0x10
    _OUTDRV = 0x04

    _DEBUG = False
    _DEBUG_INFO = 'DEBUG "PCA9685.py":'

    def __init__(self, bus_number=None, address=0x40):
        self.address = address
        if bus_number is None:
            self.bus_number = 1
        else:
            self.bus_number = bus_number
        if MOCK_ENV in os.environ and os.environ[MOCK_ENV] == 'true':
            self.bus = MockSMBus(self.bus_number)
        else:
            self.bus = SMBus(self.bus_number)
        self._frequency = 60

    def _debug_(self, message):
        if self._DEBUG:
            print(self._DEBUG_INFO, message)

    def setup(self):
        '''Init the class with bus_number and address'''
        self._debug_('Reseting PCA9685 MODE1 (without SLEEP) and MODE2')
        self.write_all_value(0, 0)
        self._write_byte_data(self._MODE2, self._OUTDRV)
        self._write_byte_data(self._MODE1, self._ALLCALL)
        time.sleep(0.005)

        mode1 = self._read_byte_data(self._MODE1)
        mode1 = mode1 & ~self._SLEEP
        self._write_byte_data(self._MODE1, mode1)
        time.sleep(0.005)
        self._frequency = 60

    def _write_byte_data(self, reg, value):
        '''Write data to I2C with self.address'''
        self._debug_('Writing value %2X to %2X' % (value, reg))
        try:
            self.bus.write_byte_data(self.address, reg, value)
        except Exception as i:
            print(i)

    def _read_byte_data(self, reg):
        '''Read data from I2C with self.address'''
        self._debug_('Reading value from %2X' % reg)
        try:
            results = self.bus.read_byte_data(self.address, reg)
            return results
        except Exception as i:
            print(i)

    @property
    def frequency(self):
        return self._frequency

    @frequency.setter
    def frequency(self, freq):
        """Set PWM frequency"""
        self._debug_('Set frequency to %d' % freq)
        self._frequency = freq
        prescale_value = 25000000.0
        prescale_value /= 4096.0
        prescale_value /= float(freq)
        prescale_value -= 1.0
        self._debug_('Setting PWM frequency to %d Hz' % freq)
        self._debug_('Estimated pre-scale: %d' % prescale_value)
        prescale = math.floor(prescale_value + 0.5)
        self._debug_('Final pre-scale: %d' % prescale)

        old_mode = self._read_byte_data(self._MODE1)
        new_mode = (old_mode & 0x7F) | 0x10
        self._write_byte_data(self._MODE1, new_mode)
        self._write_byte_data(self._PRESCALE, int(math.floor(prescale)))
        self._write_byte_data(self._MODE1, old_mode)
        time.sleep(0.005)
        self._write_byte_data(self._MODE1, old_mode | 0x80)

    def write(self, channel, on, off):
        """Set on and off value on specific channel"""
        self._debug_('Set channel "%d" to value "%d"' % (channel, off))
        self._write_byte_data(self._LED0_ON_L + 4 * channel, on & 0xFF)
        self._write_byte_data(self._LED0_ON_H + 4 * channel, on >> 8)
        self._write_byte_data(self._LED0_OFF_L + 4 * channel, off & 0xFF)
        self._write_byte_data(self._LED0_OFF_H + 4 * channel, off >> 8)

    def write_all_value(self, on, off):
        """Set on and off value on all channel"""
        self._debug_('Set all channel to value "%d"' % (off))
        self._write_byte_data(self._ALL_LED_ON_L, on & 0xFF)
        self._write_byte_data(self._ALL_LED_ON_H, on >> 8)
        self._write_byte_data(self._ALL_LED_OFF_L, off & 0xFF)
        self._write_byte_data(self._ALL_LED_OFF_H, off >> 8)

    @property
    def debug(self):
        return self._DEBUG

    @debug.setter
    def debug(self, debug):
        """Set if debug information shows"""
        if debug in (True, False):
            self._DEBUG = debug
        else:
            raise ValueError('debug must be "True" (Set debug on) or "False" (Set debug off), not "{0}"'.format(debug))

        if self._DEBUG:
            print(self._DEBUG_INFO, "Set debug on")
        else:
            print(self._DEBUG_INFO, "Set debug off")