About this Project

This project was developed in the summer of 2021 as a means for testing experimental carbon-nanotube based flow sensors. The project combines a graphical user interface (GUI) written in python, and microcontroller code written for a Teensy 4.0 using the Arduino ecosystem. The microcontroller reads sensor values from a set of Analog Devices AD7746 ICs over an I²C connection, buffers the values, and relays them to the python prgram over a USB serial connection. The python program also polls two pressure transducers over USB serial connection.

Getting Started

The following instructions assume you have a working installation of python on your machine.

To get a local copy of this project running, follow these steps.

1. Create a project folder.

2. Download the project files main.py, gui.py and requirements.txt to your project folder. The other files relate to the microcontroller code and are not necessary to run the user interface and collect data.

3. Install virtualenv.

   $ python -m pip install virtualenv
   

4. Install python dependencies.

   To do this we create a virtual environment, activate the virtual environment, and install the correct dependencies from the requirements.txt file.

   Windows

   $ virtualenv venv
   $ .\venv\Scripts\activate
   $ pip install -r requirements.txt
   

   Linux

   $ virtualenv venv
   $ source venv/bin/activate
   $ pip install -r requirements.txt
   

Use

To run the program, simply run:

python main.py

The GUI displays a representation of how the sensing elements are laid out relative to one another. A live plot of the streamed sensor values and a bar indicating the measured differential pressure are included for live monitoring of the experiment.

NOTE: As currently configured on 2021/10/17, the pressure differential bar is of little use as the scale does not adjust properly.

The sensing elements may be clicked to enable the corresponding channel and begin streaming data. With the desired data streaming, the record button may be pressed to begin writing the data to a file. The output file can be specified using the browse button in the Save Path field.

NOTE: As of 2021/10/17, the file browse button has not been connected to anything. The program writes to a file called data_log. The program will continually append to the data_log file each time the record button is pressed. The data_log file contents must be deleted prior to pressing the record button if a new file is desired.

The virtual environment can be closed with the following command:

$ deactivate

Licence

Distributed under the BSD License. See LICENSE for more information.