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#!/usr/bin/env python
# coding=utf-8
# This file is part of the PiXtend(R) Project.
#
# For more information about PiXtend(R) and this program,
# see <https://www.pixtend.de> or <https://www.pixtend.com>
#
# Copyright (C) 2018 Robin Turner
# Qube Solutions UG (haftungsbeschränkt), Arbachtalstr. 6
# 72800 Eningen, Germany
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
from __future__ import print_function
# Import Pixtend class
from pixtendlib import Pixtend
import time
import sys
strSlogan1 = "PiXtend Python Library (PPL) demo for DAC usage."
strSlogan2 = "PiXtend Python Library (PPL) demo for DAC usage finished."
# -----------------------------------------------------------------
# Print Art and Slogan
# -----------------------------------------------------------------
print("")
print(" ____ _ _ __ __ __")
print(" / __ \\ (_) | |/ / / /_ ___ ____ ____/ /")
print(" / /_/ / / / | / / __/ / _ \\ / __ \\ / __ / ")
print(" / ____/ / / / | / /_ / __/ / / / // /_/ / ")
print("/_/ /_/ /_/|_| \\__/ \\___/ /_/ /_/ \\__,_/ ")
print("")
print(strSlogan1)
print("")
# -----------------------------------------------------------------
# Create instance
# -----------------------------------------------------------------
p = Pixtend()
# Open SPI bus for communication
try:
# MC SPI 0 CS 0
p.open()
# DAC SPI 0 CS 1
p.open_dac()
except IOError as io_err:
# On error, print an error text and delete the Pixtend instance.
print("Error opening the SPI bus! Error is: ", io_err)
p.close()
p = None
# -----------------------------------------------------
# Main Program
# -----------------------------------------------------
if p is not None:
print("Running Main Program - Hit Ctrl + C to exit")
# Set some variables needed in the main loop
is_config = False
cycle_counter = 0
dac_value_1 = 0
dac_value_2 = 1023
inc_value_dac_1 = 8
inc_value_dac_2 = 8
while True:
try:
# Using Auto Mode for optimal SPI bus usage
if p.auto_mode() == 0:
cycle_counter += 1
if not is_config:
is_config = True
print("One time configuration: Setting up DAC A & B")
print("")
# -- Setup DAC A and B --
# Select DAC A
p.dac_selection = p.DAC_A
p.set_dac_output(1023)
# Select DAC B
p.dac_selection = p.DAC_B
p.set_dac_output(1023)
# Select DAC A and change its value
if dac_value_1 + inc_value_dac_1 >= 1023:
dac_value_1 = 0
# Select
p.dac_selection = p.DAC_A
# Set new output value
p.set_dac_output(dac_value_1)
dac_value_1 = dac_value_1 + inc_value_dac_1
# Select DAC B and change its value
if dac_value_2 - inc_value_dac_2 <= 0:
dac_value_2 = 1023
# Select
p.dac_selection = p.DAC_B
# Set new output value
p.set_dac_output(dac_value_2)
dac_value_2 = dac_value_2 - inc_value_dac_2
# Build text with values for DAC A & B
str_text = "Cycle No.: {0}\n".format(cycle_counter)
str_text += "DAC A: {0}\n".format(dac_value_1)
str_text += "DAC B: {0}\n".format(dac_value_2)
# Print text to console
print(str_text, end="\r")
# Reset cursor
for i in range(0, 3, 1):
sys.stdout.write("\x1b[A")
else:
print("Auto Mode - Communication is not yet up...Please wait...")
# Wait at minimum 0.1sec or 100ms before getting new values
time.sleep(0.1)
except KeyboardInterrupt:
# Keyboard interrupt caught, Ctrl + C, now clean up and leave program
p.close()
p = None
for i in range(0, 4, 1):
print("")
print(strSlogan2)
break
else:
# If there was an error when opening the SPI bus interface, leave the program.
print("")
print("There was a problem with the PiXtend communication. Quitting.")
print("")
print(strSlogan2)
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