PGAS logo
PGAS · AI NoseThe modern silver spoon, on an Arduino UNO Q
Simulation
The board's 8 × 13 LED screenready

Is this food still OK to sell?

PGAS sniffs the air above the food with three gas sensors. Press the button, then follow the screen.

  1. 1Smell clean air
    Hold the box away from food.
  2. 2Cover the food
    Box upside down, 3–5 cm above it.
  3. 3Lift and air out
    Wait until the smell is gone.
Smell strength–
nonesomestrong

Press a button to start a test.

Simulated food. On the real board, the FRESH / SPOILING / DO-NOT-SELL grade comes from a model trained on real spoilage recordings.

Inside the box

Each gas sensor's voltage goes up when it smells its gas. A 10 kΩ / 20 kΩ divider brings it down to a level the UNO Q can read safely. The numbers below update live.

MQ heaters on 5 V · common ground · each AO through 10 kΩ (top) / 20 kΩ (bottom) · DHT22 on 3.3 V Arduino UNO Q (emulated MCU API) STM32U585 MCU · sketch.ino QRB2210 Linux · pgas app Bridge (RPC) 8 × 13 LED matrix (drawn by the sketch) USB-C DHT22 VCC 3.3 V 10 kΩ pull-up 3.3 V D2 one-wire data (flashes on each read)
Engineer view: sliders, raw readings, Bridge messages

Gas at each MQ module (module output, volts)

DHT22

What the sketch reports over the Bridge

MCU time 0 s · samples 0 · draw calls / matrix.draw() 0

Sensorpinraw (14-bit)module V
MQ-135 · A0
MQ-3 · A1
MQ-2 · A2
DHT22 · D2

Features of the last test (volts above clean air)

Sensord_mediand_peakd_mean
run a test

Bridge traffic (MCU ⇄ Linux)


      
Linux side · session log

    

    
The UNO Q code path of app/sketch/sketch.ino runs on an emulated UNO Q MCU API (14-bit ADC, Bridge, LED matrix). The STM32 itself is not emulated. Food gas levels are simulation parameters, not measurements.