Arduino pcb

Freelancer Request Message (Updated with TFT feature)

Subject: Request for Full Design and Documentation – Interactive Force-Controlled Liquid Dispensing System (with TFT Display Feedback)


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Hello,

I’m looking for an experienced electronics engineer or prototype developer to design and document a complete small-scale electronic system.
The project involves pressure detection, signal processing via Arduino, and control of a liquid pump, with an additional visual feedback system on a TFT display.

Below is a full overview of what I need:


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Project Description

We want to develop a functional prototype that can:

Read variable pressure using a Force Sensitive Resistor (FSR-402) connected through a 10 kΩ voltage divider.

Process the analog signal through an Arduino UNO or Nano.

When certain programmed conditions are met, the Arduino activates a 12 V DC pump via a logic-level N-channel MOSFET (IRLZ44N or similar).

Protect the circuit with a flyback diode (1N5819) across the pump terminals.

Power all logic-level components through a buck converter (12 V → 5 V).

Provide visual feedback using two display modules:

1. 0.96″ OLED (I²C) for real-time indications,


2. TFT Display (SPI) to show a custom message once a specific number of valid pressure activations has been reached (for example, after 30 pressure readings or successful activations).



Operate from a 12 V DC power source, sharing a common ground between all modules.



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System Logic (simplified)

1. The Arduino continuously monitors the FSR input (A0).


2. Each valid press above a threshold increases a counter.


3. When the counter reaches a preset value (e.g., 30 presses), the Arduino sends a signal to display a custom message on the TFT screen (e.g., “Congratulations!”, “Goal achieved!”, etc.).


4. The OLED remains active for smaller dynamic feedback (progress, status, etc.).


5. The pump activation logic remains separate but controlled under the same Arduino board.




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Deliverables Required

1. Complete Breadboard Layout Diagram – showing all connections between:
Arduino, FSR, resistors, MOSFET, diode, pump, buck converter, OLED, and TFT.


2. Electrical Circuit Schematic – suitable for PCB development.


3. Bill of Materials (BOM) – with component models, specifications, and part numbers (preferably from European or Greek suppliers).


4. PCB Design (optional next step) – compact layout integrating all components.


5. Documentation Package:

Step-by-step assembly guide

Connection diagrams and labeling

All editable files (.fzz, .sch, .brd, .ino)

Arduino code with the TFT message logic

Clear photos or renders of the layout





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Requirements

Operation from 12 V DC

Modular, serviceable design (for easy reproduction)

Stable circuit with clean signal processing

Well-labeled schematic and wiring diagram

All firmware and project files must be provided to allow full reconstruction later



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What I Need from You

Estimated timeline

Cost proposal

Examples of similar projects (Arduino, pump control, TFT/OLED integration)


I would like to start as soon as possible and can provide any extra information or dimensions you need.

Best regards,
Manos Patsialidis