VO₂max

Code and build files for Rabbitcreek's VO₂Max Spirometer. Incorporating CO₂ enhancements from Ulrich Rissel. Build instructions on Instructable See Nik's pages for excellent build details: meteoscientific

Source code for Arduino under "VO₂Max" - Arduino board settings to use for TTGO T-Display:

Board: ESP32 Dev Module
Upload Speed: 921600
CPU Frequency: 240Mhz (WiFi/BT)
Flash Frequency: 80Mhz
Flash Mode: QIO
Flash Size: 4MB (32Mb)
Partition Scheme: Default 4MB with spiffs (1.2MB APP/1.5 SPIFFS)
Core Debug Level: None`

Source parts, top to bottom. 3M mask with front plate removed, 3D printed case, Oxygen sensor, TTGo T-Display, Flow sensor.

First finished build.

Rebuilding to use CO₂ sensor. SCD30 pictured right.

Assembled into case tightly, BM280 barometer addition mounted onto front of tube, wiring for CO₂ monitor fed behind and out to top.

Pictured with the CO₂ sensor upgrade attached

3D printing files are within the design folder, Ulrich Rissel's design files to use a larger venturi diameter with CO₂ sensor holder in design/CO2_upgrade

Additional changes in this version:

• Menu system enhanced with adjustable calibration and setup options.
• Additional GoldenCheetah integration (with VO₂ master output)
• CO₂ sensor support (Ulrich's mods)
• STC31 CO₂ sensor support
• Ability to run without O₂ sensor

More notes on the CO₂ sensor use can be found at: CO₂ sensors