Gas Sensor Readout Board

Overview:

This project allows a 4x4 array of carbon nanotube based FET gas sensors to measure real-time, near synchronous response to various gas compositions.

The PCB includes a custom analog frontend, power, and compute to enable remote acquisition of gas sensor data.

Features:

• ESP32 WROOM 32E and ESP32S2 microcontroller compatibility

• 16 bi-directional channel MUX to rapidly cycle through the 16 on board sensors 

• 16-Bit DAC to supply precise and accurate drain-source bias voltage 

• 20-Bit ADC to record change in voltage for sensor response 

• General purpose OpAmp with sensing circuitry to measure change in gas sensor current 

• Dual power inputs USB-C or LiPo Batteries with smart power switching

• USB-C Power Delivery controlled by microcontroller (5-100W)

• Rechargable battery charging circuit (LiPo, Li-ion, NiMH, NiCd, LiFePO4) (2s-4s)

• Decoupling capacitors for supply filtering

Finished PCB!

PCB successfully powers on and distributes power to each chip. USBC improperly routed; therefore the microcontroller cannot be programmed.