Vital Desk
Introduction
Vital Desk is an interactive embedded system designed to check and prevent the health risks of modern remote work environments. In a context where sedentary time has increased by an average of 2 hours per day , this project serves as a companion that bridges environmental monitoring with behavioral intervention.
- What it does: The device monitors air quality (MQ8), climate (DHT11), and user proximity (HC-SR04). It uses a servo to break the user's static posture and displays real-time health metrics on an I2C LCD.
- Purpose: To combat the lack of an optimal microclimate in improvised workspaces and reduce cardiovascular risks associated with prolonged sitting and bad posture.
- The Concept: Moving away from passive measurement toward a proactive, artistic guardian that interacts physically with the user.
- Utility: It provides a stand-alone health assistant that functions independently of a desktop PC, ensuring a healthier and more focused workflow.
General Description
- The sensors are collecting the data, such as the temperature, humidity, gas, proximity
- The data is checked and based on the limits that we set at first, we can see wether the working environment is good or not.
- If something is above or below limits, we alert through the LCD and/or servo sensor movement
- Also, there’s an alert if the user is sitting way too close to the PC that they work on, or if the user hasn’t been standing for a longer period of time.
Hardware Design
Electrical Scheme (done in Wokwi)
- Microcontroller: Arduino-UNO board.
- Climate Sensor: DHT11 for temperature and humidity tracking.
- Air Quality Sensor: MQ8 for gas and CO2 detection.
- Proximity Sensor: HC-SR04 Ultrasonic sensor to detect user presence/absence and how close the user is sitting to their computer.
- Actuator: SG90 Servomotor for physical intervention.
- Display: LCD 1602 with I2C interface for status updates.
- Connectivity: USB cable.
Proposed pinout
Arduino UNO:
| Component | Arduino Pins | |
|---|---|---|
| DHT11 | DATA → D7 (PD7), VCC → 5V, GND → GND | |
| HC-SR04 | TRIG → D9 (PB1), ECHO → D8 (PB0), VCC → 5V, GND → GND | |
| MQ-8 Gas Sensor | AO → A0 (PC0 / ADC0), VCC → 5V, GND → GND | |
| SG90 Servo | Signal → D6 (PD6), VCC → 5V, GND → GND | |
| LCD 1602 (I2C) | SDA → A4 (PC4), SCL → A5 (PC5), VCC → 5V, GND → GND | |
| Buttons (x4) | D2, D3, D4, D5 (PD2-PD5), INPUT_PULLUP, common pin → GND |
Button mapping:
- Button 1 (D2): ARM / DISARM the system.
- Button 2 (D3): Monitoring screen (temperature, humidity, gas, distance).
- Button 3 (D4): Temperature min / max screen.
- Button 4 (D5): Humidity min / max screen.
Power Supply: The project is directly linked to the Laptop, using a USB cable, making the data collection easier. All sensors are powered through 5V from the Arduino UNO.
Software Design
- PlatformIO with the Arduino framework (board:
uno, platform:atmelavr). - Build flags:
-Os(optimize for size) and-Wall(all warnings). - Serial monitor speed: 9600 baud.
3rd-party libraries
The firmware uses a small set of well-known Arduino libraries (declared in platformio.ini under lib_deps):
- DHT sensor library (Adafruit) + Adafruit Unified Sensor - reading the DHT11 temperature and humidity.
- LiquidCrystal_I2C (marcoschwartz) - driving the 1602 LCD over I2C.
- Servo (arduino-libraries) - generating the control pulses for the SG90.
The GPIO access for the HC-SR04 and the buttons, as well as the MQ-8 ADC reads, are done bare-metal (direct register manipulation), in the PM lab style, instead of using digitalRead/analogRead.
Alert thresholds:
Alert Trigger When? |
| Temperature | T > 28 C | immediate |
| Humidity | H > 65 % | immediate |
| Gas | gas > 250 ppm | immediate |
| Too far | distance > 30 cm | held for 10 s |
| Too close | distance < 10 cm | held for 30 s |
For the distance alerts, a generic temporal timer requires the condition to hold continuously for the configured duration before the alert fires; an ultrasonic timeout reading is treated as “very far” (nobody at the desk) so that walking away is detected reliably.
Rezultate Obţinute
Conclusions
Vital Desk meets its original goal: a stand-alone health assistant that monitors the work environment and intervenes physically and visually when something is off, without depending on a host PC for its logic. The most useful lessons from the project were on the debugging side rather than the feature side. The servo jitter was instructive: it showed clearly where the boundary between a software fix and a hardware fix lies. Spacing out the I2C traffic and the servo activity in firmware reduced the symptom, but the residual jitter is a current/power problem that software cannot fully solve.
If the project were continued, the natural next steps would be: a dedicated 5V supply for the servo to eliminate the remaining jitter, replacing the _delay_ms-based tick with a hardware timer so the 10 s / 30 s timers are exact.
Download
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Fişierele se încarcă pe wiki folosind facilitatea Add Images or other files. Namespace-ul în care se încarcă fişierele este de tipul :pm:prj20??:c? sau :pm:prj20??:c?:nume_student (dacă este cazul). Exemplu: Dumitru Alin, 331CC → :pm:prj2009:cc:dumitru_alin.
Jurnal
Bibliografie/Resurse
