# -*- coding: utf-8 -*-
__author__ = 'ke4roh'
# Specifics of communication channels with the Si4707
#
# Copyright © 2016 James E. Scarborough
#
# 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/>.
import RPi.GPIO as gpio
from time import sleep
import signal
import Adafruit_GPIO.I2C
from RPiNWR.Si4707 import Context
# TODO wrap this so that it will be cleaned up EVERY time
# --- see http://stackoverflow.com/questions/865115/how-do-i-correctly-clean-up-a-python-object#865272
class AIWIBoardContext(Context):
"""
This class encapsulates the context through which the radio is used,
providing adapters to the functionality to reset the radio,
write to it, and read from it. A duck-wise compatible class can be used
to adapt to any context.
This class is not thread-safe.
This must be instantiated from the main thread - which is the default, because it sets
interrupt handlers. If you need to set your own interrupt handlers, ensure that you call
shutdown to clean things up, else you won't be able to run it again without power-cycling
your Raspberry Pi.
"""
__signals_trapped = False
relay_gpio_pins = [13, 19]
i2c = Adafruit_GPIO.I2C.get_i2c_device(0x11)
def __init__(self):
super(AIWIBoardContext, self).__init__()
self.gpio_started = False
def reset_radio(self):
"""
Reset the Si4707 chip
"""
# Ref https://github.com/AIWIndustries/Pi_4707/blob/master/firmware/NWRSAME_v2.py
if self.gpio_started:
gpio.cleanup()
self.gpio_started = True
gpio.setmode(gpio.BCM) # Use board pin numbering
gpio.setup(17, gpio.OUT) # Setup the reset pin
gpio.output(17, gpio.LOW) # Reset the Si4707.
sleep(0.4)
gpio.output(17, gpio.HIGH)
gpio.setup(23, gpio.IN, pull_up_down=gpio.PUD_UP)
gpio.add_event_detect(23, gpio.FALLING)
# Initialize the onboard relays
for pin in self.relay_gpio_pins:
gpio.setup(pin, gpio.OUT) # setup gpio pin for relay
gpio.output(pin, gpio.LOW) # boot to disabled state
# set up the LED
# https://www.reddit.com/r/raspberry_pi/comments/3641ug/blinking_an_onboard_led_on_the_pi_2_model_b/
# http://raspberrypi.stackexchange.com/questions/697/how-do-i-control-the-system-leds-using-my-
# sudo echo none >/sys/class/leds/led0/trigger
# GPIO 16 LOW is on, HIGH is off
gpio.setup(16, gpio.OUT)
gpio.output(16, gpio.HIGH)
sleep(1.5)
def write_bytes(self, data):
# TODO make this accept bytes(...)
if len(data) == 1:
self.i2c.write8(data[0], 0)
else:
self.i2c.writeList(data[0], data[1:])
def read_bytes(self, num_bytes):
# TODO make this return bytes(...)
return self.i2c.readList(0, num_bytes)
def __enter__(self):
# Make sure to cleanup GPIO afterward
if not self.__signals_trapped:
self.__signals_trapped = True
for sig in [signal.SIGQUIT, signal.SIGTERM, signal.SIGTSTP]:
if hasattr(signal.getsignal(sig), '__call__'):
deleg = signal.getsignal(sig)
def delegate(signum, stack):
self.__exit__(None, None, None)
deleg(signum, stack)
signal.signal(sig, delegate)
else:
def delegate(signum, stack):
self.__exit__(None, None, None)
signal.signal(sig, delegate)
return self
def __exit__(self, exc_type, exc_val, exc_tb):
try:
if self.gpio_started:
gpio.cleanup()
self.gpio_started = False
except RuntimeError:
self._logger.info("Cleanup trouble", exc_info=True)
pass # Probably tried to do it twice
def relay(self, num, on):
if on:
status = gpio.HIGH
else:
status = gpio.LOW
gpio.output(self.relay_gpio_pins[num], status)
def led(self, on):
if not on:
status = gpio.HIGH
else:
status = gpio.LOW
gpio.output(16, status)
