Compact Optical Sensing Module PCBs Design

We are developing a compact optical sensing module and are looking for a freelancer to design, assemble, and deliver two connected PCBs for the system.

Scope of Work

LED PCB (Optical Head)

Use SFH7018B multi-wavelength LED.

PCB must be circular, with a maximum diameter of 10 mm.

Designed for close coupling with an optical sensor (mechanical alignment is critical).

Proper thermal pad connection and heat dissipation are required.

No onboard control logic—LEDs will be driven externally.

LED Driver PCB, Module should be compatible with PWM dimming.

Separate PCB that drives the SFH7018B LED channels.

Must support individual wavelength control (current-controlled driving).

Designed to interface directly with an existing Raspberry Pi Pico board.

Control via Pico GPIO / PWM / I²C (final interface to be discussed).

Should include necessary protection, filtering, and stable current regulation.

System Integration

LED PCB and Driver PCB connected via a compact connector or cable.

Driver PCB powered and controlled by the Pico (Pico not to be redesigned).

The freelancer is responsible for:

Schematic design

PCB layout

Component selection

PCB fabrication

Assembly and delivery of working hardware

Deliverables

Assembled LED PCB (≤10 mm diameter)

Assembled LED Driver PCB

Tested hardware compatible with Raspberry Pi Pico control

Skills Required

PCB design (compact and high-density layouts)

LED driver circuits (constant current design)

Experience with Raspberry Pi Pico / microcontroller interfacing