Custom 48-pin MCU Controller PCB Design

Custom Motherboard with Microchip 48‑pin MCU – 2x 3‑Digit & 1x 7‑Digit Seven‑Segment Displays, Oxygen Sensor, 3x 12V Solenoid Valves, Flowmeter, 10‑Key Touch Keypad, 2x I2C LCDs, Water Level Sensor, Thermal Printer, 12V Relay for Motor

Project Overview

I need a custom motherboard (schematic, PCB layout, and firmware) based on a Microchip 48‑pin SMD MCU (TQFP‑48). The board must interface with:

· 2x 3‑digit seven‑segment displays
· 1x 7‑digit seven‑segment display
· Oxygen sensor
· 3x 12V solenoid valves – controlled via on‑board MOSFETs
· 1x flowmeter – pulse output, interrupt input
· 1x 10‑key touch keypad
· 2x I2C LCD displays (16×2)
· 1x water level sensor
· 1x thermal printer
· 1x 12V relay for motor – MCU‑controlled via transistor/MOSFET
· 3‑pin power input: 5V, 12V, GND (supply already available)
· 4‑pin programming port (ICSP: PGD, PGC, MCLR, GND)

Deliverables

1. Schematic & PCB layout (Gerbers, BOM, Pick & Place)
2. Firmware (C for Microchip – MPLAB X) that:
· Reads all sensors (I2C, analog, digital)
· Reads flowmeter pulses via interrupt
· Drives the 3 seven‑segment displays
· Drives 2x I2C LCDs
· Reads the 10‑key touch keypad
· Controls 3 solenoid valves via GPIO → MOSFET
· Controls the 12V relay for motor
· Sends print data to the thermal printer over UART
· Supports in‑circuit programming via 4‑pin header
3. Source code, fully commented
4. Assembly / connection guide for external components

· Exact part numbers and data sheets for sensors, displays, keypad, thermal printer, and relay
· Power supply specifications (5V/12V current limits)
· Any specific logic or behavior required for solenoids, relay, and printer

How to Apply

Send me:

1. Examples of similar custom PCB + firmware projects
2. Proposed MCU model and why you recommend it
3. Brief approach for driving the seven‑segment displays and handling multiple I2C devices
4. Your typical workflow (schematic → layout → prototype → firmware)