TTMSB USB

Test and control board for PIC18F4550, including PCB design and firmware written in CCS C Compiler (CCSC).

The board communicates via USB (virtual COM port) or UART, allowing control and monitoring of several peripherals.

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Features

• Control of two DC motors
• Switching two high-power devices (relays)
• Temperature sensing using a digital or analog sensor
• Real-Time Clock (RTC) for maintaining current time even when powered off
• Sound signaling (buzzer or speaker)
• Communication via USB CDC (virtual UART) or hardware UART

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UART Configuration

Parameter	Value
Baud rate	115200 bps
Data bits	8
Parity	None
Stop bits	1
Flow control	Hardware

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USB / UART Commands

The board listens for single-character commands over USB or UART.

Command	Function
s	Sound signal (buzzer)
m	Toggle relay 1 ON/OFF
n	Toggle relay 2 ON/OFF
t	Read temperature
l	Motor left
r	Motor right
d	Motor down / backward
u	Motor up / forward
y	Read time from RTC
a	Sync RTC with local (PC) time
o	Set RTC manually
p	Test routine
x	Reset microcontroller (CPU)

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Hardware Overview

• Microcontroller: PIC18F4550
• USB interface: Full-speed USB 2.0 via internal PIC module
• Power supply: USB-powered or external (5 V)
• Clock: 20 MHz crystal (configured for USB)
• I/O:
  • 2× DC motor driver channels
  • 2× relay outputs
  • 1× temperature sensor input
  • 1× RTC module (e.g., DS1307/DS3231)
  • 1× buzzer

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Development

• Firmware written in CCS C (.c and .h sources)
• Compatible with MPLAB IDE or CCS IDE
• Simple serial command protocol for debugging and control
• Supports firmware updates via ICSP

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License

This project is open hardware and software under the CC BY-SA license.
You are free to reproduce, modify, and share this project with attribution.

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© 2013 Marcin Filipiak