PIC18F Elevator Control Board

Embedded elevator controller firmware and hardware documentation for a custom PIC18F46K22-based control board.

Project Summary

This project was developed as a final-year engineering project in electromechanics to design a local elevator control board that is easier to maintain, less dependent on imported hardware, and better adapted to real industrial needs.

The repository brings together:

• embedded firmware for a 4-level elevator controller
• state-machine-based control logic
• board support and relay control modules
• PCB design visuals and system documentation extracted from the final report

GitHub Description

PIC18F46K22 elevator control board with a finite state machine, relay control, safety logic, and custom PCB design.

Objectives

• Design a dedicated elevator control board around the PIC18F46K22
• Control cabin movement, door actions, and floor indication
• Integrate safety-related inputs and technician mode behavior
• Build a maintainable firmware structure that is easier to debug and extend
• Reduce dependence on imported controller boards by proposing a local solution

Key Features

• Finite state machine for elevator movement between ground floor, floor 1, floor 2, and floor 3
• Normal operating mode and technician mode
• Relay-based control for up, down, high-speed, and low-speed motion
• Door management and floor display handling
• Safety-oriented behavior using dedicated inputs, contactor feedback, and interrupts
• Command-line build with MPLAB XC8

System Overview

The control architecture is centered around a PIC18F46K22 microcontroller. Inputs collect floor requests, sensor edges, limit switch states, manual maintenance commands, and safety events. The firmware processes these signals through a state machine, then drives the elevator relays, door outputs, and display logic.

The codebase is structured so that application logic, board support, and platform-specific startup code are clearly separated.

Visual Overview

Functional View

Program Logic

PCB Design

PCB Routing

Control Logic

The firmware implements a state machine that manages elevator behavior according to the active mode and the requested floor.

In normal mode, the controller:

• reads calls from floor buttons or serial commands
• starts movement in the correct direction
• switches between high-speed and low-speed travel
• counts sensor events to detect position changes
• stops the cabin on the requested floor
• opens and closes the door once arrival is confirmed

In technician mode, the controller:

• allows manual up and down control
• keeps door and motor actions under controlled conditions
• separates maintenance behavior from normal passenger operation

Firmware Structure

firmware/
  include/
    app/
      elevator_control.h
      elevator_state_machine.h
    bsp/
      input_config.h
      output_config.h
    platform/
      eusart1.h
      interrupt_manager.h
      mcc.h
      system_init.h
  src/
    app/
      main.c
      elevator_control.c
      elevator_state_machine.c
    bsp/
      input_config.c
      output_config.c
    platform/
      eusart1.c
      interrupt_manager.c
      mcc.c
      system_init.c
docs/
  assets/
  project-structure.md

Build

This repository can be built from the command line with MPLAB XC8.

Requirements:

• xc8-cc
• PIC18F-K_DFP

Build commands:

make
make clean
make print-config

Main outputs:

• build/elevator.production.elf
• build/elevator.production.hex

Hardware Platform

• Microcontroller: PIC18F46K22
• Relay outputs for motion and auxiliary control
• Floor request inputs
• Limit switches and movement sensors
• Safety-related inputs
• Seven-segment display support
• Serial communication support

Documentation Source

Some diagrams and PCB visuals included in this README