From 2186336bbc42d11fdee3c91ab1f49cc1a460cc21 Mon Sep 17 00:00:00 2001 From: Fabio Manganiello Date: Tue, 17 Apr 2018 01:02:55 +0200 Subject: [PATCH] Added plugin for supporting MCP3008 ADC for analog sensors --- .../plugins/gpio/sensor/mcp3008/__init__.py | 88 +++++++++++++++++++ setup.py | 2 + 2 files changed, 90 insertions(+) create mode 100644 platypush/plugins/gpio/sensor/mcp3008/__init__.py diff --git a/platypush/plugins/gpio/sensor/mcp3008/__init__.py b/platypush/plugins/gpio/sensor/mcp3008/__init__.py new file mode 100644 index 000000000..e3bbf6f7a --- /dev/null +++ b/platypush/plugins/gpio/sensor/mcp3008/__init__.py @@ -0,0 +1,88 @@ +import enum +import logging +import time + +import Adafruit_GPIO.SPI as SPI +import Adafruit_MCP3008 + +from platypush.plugins.gpio.sensor import GpioSensorPlugin +from platypush.message.response import Response + + +class MCP3008Mode(enum.Enum): + SOFTWARE = 'software' + HARDWARE = 'hardware' + + +class GpioSensorMcp3008Plugin(GpioSensorPlugin): + """ + Plugin to read analog sensor values from an MCP3008 chipset, + see https://learn.adafruit.com/raspberry-pi-analog-to-digital-converters/mcp3008 + Requires adafruit-mcp3008 Python package + """ + + N_CHANNELS = 8 + + def __init__(self, CLK=None, MISO=None, MOSI=None, CS=None, spi_port=None, + spi_device=None, channels=None, Vdd=3.3, *args, **kwargs): + super().__init__(*args, **kwargs) + + if CLK and MISO and MOSI and CS: + self.CLK = CLK + self.MISO = MISO + self.MOSI = MOSI + self.CS = CS + self.mode = MCP3008Mode.SOFTWARE + elif spi_port and spi_device: + self.spi_port = spi_port + self.spi_device = spi_device + self.mode = MCP3008Mode.HARDWARE + else: + raise RuntimeError("At least one mode must be specified.\n" + + "Software SPI: Specify CLK, MISO, MOSI and CS pins\n" + + "Hardware SPI: Specify spi_port and spi_device\n") + + self.Vdd = Vdd + self.channels = channels if channels else {} + self.mcp = None + + + def _get_mcp(self): + if self.mode == MCP3008Mode.SOFTWARE: + self.mcp = Adafruit_MCP3008.MCP3008(clk=self.CLK, cs=self.CS, + miso=self.MISO, mosi=self.MOSI) + elif self.mode == MCP3008Mode.HARDWARE: + self.mcp = Adafruit_MCP3008.MCP3008(spi=SPI.SpiDev(self.spi_port, self.spi_device)) + else: + raise RuntimeError('Unsupported MCP3008 mode: {}'.format(self.mode)) + + return self.mcp + + + def _convert_to_voltage(self, value): + return (value * self.Vdd) / 1023.0 if value is not None else None + + + def get_measurement(self): + mcp = self._get_mcp() + values = {} + + for i in range(self.N_CHANNELS): + value = self._convert_to_voltage(mcp.read_adc(i)) + + if self.channels: + if i in self.channels: + channel = self.channels[i] + if 'conv_function' in channel: + x = value + value = eval(channel['conv_function']) + + values[channel['name']] = value + else: + values[i] = value + + return Response(output=values) + + +# vim:sw=4:ts=4:et: + diff --git a/setup.py b/setup.py index 0ecf080f1..ab30d9655 100755 --- a/setup.py +++ b/setup.py @@ -80,6 +80,8 @@ setup( 'Support for most of the HTTP poll backends': ['python-dateutil'], 'Support for Last.FM scrobbler plugin': ['pylast'], 'Support for custom hotword detection': ['snowboy'], + 'Support for GPIO pins access': ['RPi.GPIO'], + 'Support for MCP3008 analog-to-digital converter plugin': ['adafruit-mcp3008'], # 'Support for Flic buttons': ['git+ssh://git@github.com/50ButtonsEach/fliclib-linux-hci'] }, )