Setup

Install software on Teensy

1. Install Arduino IDE
   • https://www.arduino.cc/en/Main/Software
2. Install Teensyduino, dowload and instructions are available here
   • https://www.pjrc.com/teensy/td_download.html
3. Plug in Teensy and select proper board and port
   • Tools -> Board -> Teensy 3.1/3.2
   • Tools -> Port -> Select Teensy Port
4. Download pedvide ADC library and add to Arduino
   • Download as .zip from https://github.com/pedvide/ADC
   • In the Arduino IDE: Sketch -> Include Library -> Add .ZIP Library
   • Select downloaded .zip
5. Download and open appropriate .ino file and Click 'Upload'

Pull data with Python

Use one of the scripts here or write your own to find and pull data from the serial port. The current recommended firmware is dual_diff_read_with_interval_timer.ino.

Sending s #### will set the sampling period to #### us. We usually operate pulling data every 1 ms (s 10000). Sending s or s 0 will stop sampling.

Hardware

Teensy 3.2

The Teensy 3.2 has two ADCs with internal amplifiers that can run in differential mode. In differential mode each ADC can only use certain pins.

A10 - ADC 0 diff +
A11 - ADC 0 diff -
A12 - ADC 1 diff +
A13 - ADC 1 diff -

Honeywell 24PCFFA6G Pressure Sensor

Sensor details can be found here.

Pertinent details from the datasheets:

Note:

• Pin 1 is notched (very slightly, you'll really have to look for it)
• 2.5-12 V supply voltage, typical is listed at 10 V. Higher voltage -> better SNR
• Our sensors use gague measurement relative to ambient pressure and and are rated for 100 PSI
• Increasing pressure results in increasingly negative differential voltage between pins 2 and 4

Wiring

• Connect the USB output to computer
• Connect sensor pin 1 to V+ (source voltage, 1.5-12V)
• Connect sensor pin 2 to Teensy pin A10 for ADC0 (or A12 for ADC1)
• Connect sensor pin 3 to V- (source ground)
• Connect sensor pin 4 to Teensy Pin A11 for ADC0 (or A13 for ADC1)

Software

gui_live.py provides a fast, simple user interface.

For more details about how embedding the live animation in the PySimleGUI frontend works, see this article:

• https://matplotlib.org/3.1.0/gallery/user_interfaces/embedding_in_tk_sgskip.html)