An intelligent desk environment monitor built on the Raspberry Pi Pico and written in MicroPython. Sentinel-Pico uses a proximity sensor to detect whether someone is sitting at the desk, then reads temperature, humidity, and ambient light to display contextual information on a small OLED screen. Try it online on on Wokwi.

• Overview
• Features
• Hardware / Components
• Wiring / Pinout
• Logic Flow
• Repository Structure
• Quick Start
• Configuration
• Simulated Screens
• Troubleshooting
• License
• Contributing

Sentinel-Pico turns any desk into a smart monitoring station. When no one is detected within 50 cm, the OLED display enters a low-power idle screen. When someone sits down, it immediately reports ambient conditions and alerts the user if the lighting is too dim for comfortable work.k.

• Presence detection via HC-SR04 ultrasonic sensor
• Temperature & humiditydity readout from a DHT22 sensor
• Ambient light monitoring with a photoresistor (LDR)
• OLED display driven by an SSD1306 over I2C
• Three distinct display modes based on real-time sensor data
• Fully simulated on Wokwi, no physical hardware

SSD1306 OLED  →  SDA: GP4, SCL: GP5, VCC: 3.3 V, GND
DHT22         →  DATA: GP14, VCC: 3.3 V, GND
LDR Sensor    →  OUT: GP26 (ADC0), VCC: 3.3 V, GND
HC-SR04       →  TRIG: GP28, ECHO: GP27, VCC: 5 V (VBUS), GND
ND

Loop:
 ├── Measure distance (HC-SR04)
 │
 ├── Distance > 50 cm  OR  sensor error
 │    └── OLED: "Nobody Detected / Shutdown"
 │
 └── Distance ≤ 50 cm (someone at desk)
      ├── Read DHT22 (temperature + humidity)
      ├── Read LDR (ambient light level)
      │
      ├── LDR ADC value ≥ 32727  (≤ ~100 lux — too dark)
      │    └── OLED: "Please turn on the light!"
      │
      └── LDR ADC value < 32727  (bright enough)
           └── OLED: "Hi Sir! / Humidity: X% / Temp: X °C"
                └── Wait 5 s, then repeat
epeat
s, then repeat

SENTINEL-PICO/
├── deskstation.py     # Main application logic (MicroPython)
├── journal.md         # Dev log / Hack Club Lapse links
├── desktop-station.zip # Wowki source file including libraries
└── README.md
.md

Note: ssd1306.py (the OLED driver) must be placed on the Pico alongside deskstation.py. You can download it from the MicroPython SSD1306 driver.

Open the project directly on Wokwi: https://wokwi.com/projects/462996062362677249

1. Flash MicroPython v1.24.1 (or later) on your Raspberry Pi Pico.
2. Download ssd1306.py from the MicroPython library (link above).
3. Copy deskstation.py and ssd1306.py to the Pico using Thonny or mpremote:

   mpremote cp deskstation.py :main.py
   mpremote cp ssd1306.py :ssd1306.pyy
4. Wire the components according to the Wiring / Pinout section.
5. Power up : the program starts automatically on boot.

All tunable values are located at the top of deskstation.py:

No one detected (distance > 50 cm)cm)

Too dark (ambient light < 100 lux)ux)

Normal operation (temperature & humidity displayed)yed)

This project is licensed under the MIT License — see the LICENSE file for details.

Contributions, improvements, and remixes are welcome! Please read the CONTRIBUTING.md guide to get started.