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#!/usr/bin/env python
# coding=utf-8
# MIT License
#
# Copyright (C) 2021 Kontron Electronics GmbH <support@pixtend.de>
#
# 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
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.
#
# For further details see LICENSE.txt.
# -----------------------------------------------------------------------------
# Attention:
# The PiXtend Python Library v2 (PPLv2) was developed as a Python
# library / module to make use of the inheritance functionality of Python.
# However, since the library must access the hardware based SPI bus on the
# Raspberry Pi only ONE single instance of the PiXtendV2S or PiXtendV2L
# class per PiXtend is allowed! The PPLv2 as well as the SPI bus is not
# capable of aggregating (multiplexing) multiple instances of either
# PiXtend class. Please keep this in mind when developing your application.
# We suggest building one central program which creates the PiXtend object
# and all other programs, functions, threads use inter-process communication
# with the main program to send data to the PiXtend board to manipulate the
# analog and/or digital outputs or to get information from the inputs.
# -----------------------------------------------------------------------------
from __future__ import print_function
# Import PiXtend V2 class
from pixtendv2l import PiXtendV2L
import time
import sys
# -----------------------------------------------------------------
# Create instance - SPI communication starts automatically
# -----------------------------------------------------------------
# PiXtend V2 -L- with DAC, Analog Output active, default/factory setting
p = PiXtendV2L()
# PiXtend V2 -L- with CAN-Bus active, physical jumper set from AO to CAN,
# the DAC device in the PPLv2 has to be disabled. Comment out the above line
# and comment in the line below to be able to use the CAN-Bus along side or
# from within Python. This requires PPLv2 Version 0.1.4 or later.
#p = PiXtendV2L(disable_dac=True)
if p is not None:
is_config = False
# Set some variables needed in the main loop
cycle_counter = 0
p.pwm1a = 0
while True:
try:
# Check if SPI communication is running and the received data is correct
if p.crc_header_in_error is False and p.crc_data_in_error is False:
cycle_counter += 1
print ("cycle_counter: %s" % (cycle_counter))
#If this is the first run, configure the PWM 1 channel A
if not is_config:
is_config = True
# Mode: Duty-Cycle, Freq: 2 kHz, Dyte-Cycle 50% - 100%, Chan: A = On
# Bit 0 - Mode0 = 1
# Bit 1 - Mode1 = 0
# Bit 2 - Reserved = 0
# Bit 3 - EnableA = 1
# Bit 4 - EnableB = 0
# Bit 5 - Prescaler0 = 1
# Bit 6 - Prescaler1 = 0
# Bit 7 - Prescaler2 = 0
# => 41
p.pwm1_ctrl0 = 41
# 16.000.000 / 2 / 1 / 4000 = 2000 Hz
# 4000 Steps
p.pwm1_ctrl1 = 4000
if cycle_counter <= 1:
p.pwm1a = 2000
print("2000 - 50%")
if cycle_counter == 6:
p.pwm1a = 3000
print("3000 - 75%")
if cycle_counter == 16:
p.pwm1a = 4000
print("4000 - 100%")
if cycle_counter >= 18 and cycle_counter < 20:
p.pwm1a = 0
print("0")
if cycle_counter >= 20:
cycle_counter = 0
# Wait some time for the next loop
time.sleep(5)
except KeyboardInterrupt:
# Leaving the program, turn off the PWM
p.pwm1_ctrl0 = 0
# Set PWM value to 0
p.pwm1a = 0
# Wait
time.sleep(0.25)
p.close()
p = None
break
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