signal-generator

Control package for an open-source signal generator board.

The signal generator board is part of the Dropbot digital microfluidics automation system, designed and built in the Wheeler Lab.

Overview

This package contains:

• Firmware compatible with Arduino Uno.
• Installable Python package for interfacing with Arduino firmware through serial port or i2c (through a serial-to-i2c proxy).

Install

The Python package can be installed through pip using the following command:

pip install wheeler.signal-generator

Upload firmware

To upload the pre-compiled firmware included in the Python package, run the following command:

python -m signal_generator.bin.upload <board type>

replacing <board type> with either uno or mega2560, depending on the model of the board.

This will attempt to upload the firmware by automatically discovering the serial port. On systems with multiple serial ports, use the -p command line argument to specify the serial port to use. For example:

python -m signal_generator.bin.upload -p COM3 uno

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Usage

After uploading the firmware to the board, the signal_generator.Proxy class can be used to interact with the Arduino device.

See the session log below for example usage.

Example interactive session

>>> from serial import Serial
>>> from signal_generator import Proxy

Connect to serial device.

>>> serial_device = Serial('/dev/ttyUSB0', baudrate=115200)

Initialize a device proxy using existing serial connection.

>>> proxy = Proxy(serial_device)

Query descriptive properties of device.

>>> proxy.properties()
base_node_software_version                               0.9.post8.dev141722557
name                                                                  signal_generator
manufacturer                                                        Wheeler Lab
url                           http://github.com/wheeler-microfluidics/signal...
software_version                                                            0.1
dtype: object

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Firmware development

The Arduino firmware/sketch is located in the signal_generator/Arduino/signal_generator directory. The key functionality is defined in the signal_generator::Node class in the file Node.h.

Running the following command will build the firmware using SCons for Arduino Uno and will package the resulting firmware in a Python package, ready for distribution.

paver sdist

Adding new remote procedure call (RPC) methods

New methods may be added to the RPC API by adding new methods to the signal_generator::Node class in the file Node.h.

Author

Copyright 2015 Christian Fobel christian@fobel.net, Ryan Fobel ryan@fobel.net