This tool is for testing and educational use.
It is not intended to confirm the mix of breathing gases. If this tool is used a separate test is needed with an appropriate and calibrated and tested O2 and He sensor.
This tool will provide information for mixing Air, O2, and He with a SCUBA compressor. The intended use is to have two O2 sensors that are able to calculate a mix before it goes into a compressor. Two "Nitrox" sticks are used in series. One to mix in He and one to mix in O2. The tool can also be used as a nitrox analyser.
- Install latest Raspberry Pi OS with desktop.(2021-05-07-raspios-buster-armhf.img Tested)
- Under Raspberry Pi Configuration --> Interfaces --> Enable "I2C"
- pip install Adafruit_ADS1x15
- sudo apt-get install python3-tk
- git clone git://github.com/divetools/Gas-Blending.git
- ln -s ~/Gas-Blending/HEALTH.desktop ~/Desktop/HEALTH.desktop
- Open File Manager --> Select Edit --> Preferences --> General Tick the option "Don't ask options on launch executable file"
Wire up an Adafruit ADS1115 to the pi I2C GPIOs. Connect two O2 sensors to port 0 and 1 on the ADS.
2021 Update - In an effort to reduce cost, I designed a new hardware case for the project. This case is 3D printed and will reduce the cost of the project. The STL's can be found at https://www.thingiverse.com/thing:4892104 for download and printing.
| Part Name | QTY | Price | Link |
|---|---|---|---|
| Raspberry Pi 3 B+ Motherboard | 1 | $55.96 | Amazon |
| Raspberry Pi 3 Power Supply 5V 2.5A | 1 | $9.99 | Amazon |
| HiLetgo ADS1115 16 Bit | 1 | $6.99 | Amazon |
| Micro SD Flash Drive | 1 | $13.89 | Amazon |
| Raspberry Pi Official 7 Inch Touch Screen | 1 | $69.99 | Amazon |
| 3.5mm Stereo Jack | 4 | $3.20 | Amazon |
| Total: | $160.02 |
