Arduino Vacuum Gauge

Absolute pressure is referenced to the pressure in a vacuum whereas gauge and differential pressures are referenced to another pressure such as the ambient atmospheric pressure or pressure in an adjacent vessel.

Arduino vacuum gauge.

Those sensors are ratiometric. Pressure measurement methods air pressure measurement using mpx5010dp. Arduino code for air pressure measurement. When the 5v changes the resulting measured pressure does not change and is still accurate.

Initial build used a 10k pot in place of a vacuum gauge to make it simpler. The oled screen simply plugs in over the arduino which made for a nice compact board. The processor in the vacuum gauge reads the 4 vacuum ports simultaneously digital filtering is applied to smooth out the vacuum readings useful on idling engines to get a steady reading the filtered value is then converted to kpa psi inhg or mmhg the calibration data from the eeprom is added to each of the vacuum readings. Power them with the arduino 5v and use the arduino 5v as analog reference that is the arduino default setting.

This had to be changed to a 0 5vdc range using a potential divider so it was compatible with the arduino.