upm/examples/python/mcp2515-txrx.py
Noel Eck 18b8ca2633 examples/python: Add/update shebang line
Added/updated the shebang line on all python examples with:

Also chmod +x a few of the python examples.

Signed-off-by: Noel Eck <noel.eck@intel.com>
2017-11-02 15:39:45 -07:00

100 lines
3.7 KiB
Python
Executable File

#!/usr/bin/env python
# Author: Jon Trulson <jtrulson@ics.com>
# Copyright (c) 2016 Intel Corporation.
#
# 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.
from __future__ import print_function
import time, sys, signal, atexit
from upm import pyupm_mcp2515 as MCP2515
def main():
# Instantiate a MCP2515 on SPI bus 0 using a hw CS pin (-1).
sensor = MCP2515.MCP2515(0, -1)
## Exit handlers ##
# This function stops python from printing a stacktrace when you
# hit control-C
def SIGINTHandler(signum, frame):
raise SystemExit
# This function lets you run code on exit, including functions from sensor
def exitHandler():
print("Exiting")
sys.exit(0)
# Register exit handlers
atexit.register(exitHandler)
signal.signal(signal.SIGINT, SIGINTHandler)
# by default we just receive packets
do_tx = False;
if (len(sys.argv) > 1):
do_tx = True
# NOTE: This example assumes that only two devices are connected
# to the CAN bus, and that both devices are running this example;
# one in TX (transmit) mode, and one in RX (receive) mode.
# If this is not the case, then in rx mode you may see other
# packets from other devices, or not, depending on whether the
# speed is correct for the network. In tx mode, errors may be
# generated on the bus, especially if the CAN bus speed does not
# match the rest of the network.
# You should start the receiver example first. The transmitter
# example will fail after about 5 seconds (timeout) of not being
# able to transmit a message.
# By default, after initialization, the baud rate is set to
# 50Kbps, and the mode is NORMAL, so we don't need to set any of
# that here.
while (True):
if (do_tx):
print("Loading a packet of 8 numbers (0-7) into a TX buffer...")
myPayload = "01234567";
sensor.loadTXBuffer(MCP2515.MCP2515_TX_BUFFER0, 0, False,
False, myPayload);
# now lets try to transmit it
print("Transmitting packet...")
sensor.transmitBuffer(MCP2515.MCP2515_TX_BUFFER0, True)
print("Transmit successful")
print()
time.sleep(.5)
else:
# RX mode
# Look for a packet waiting for us in RXB0
if (sensor.rxStatusMsgs() == MCP2515.MCP2515_RXMSG_RXB0):
print("Packet received in RXB0, decoding...")
# now lets retrieve and print it
sensor.getRXMsg(MCP2515.MCP2515_RX_BUFFER0)
sensor.printMsg();
print()
print("Exiting...")
if __name__ == '__main__':
main()