Simple RS232 Interface

fully software controlled RS232 transmission and reception for PIC16F84

Table of Contents [Toc]

Project Resources
   Available Microchip PIC Assembler Source Code
   Schematic, Data Sheets, Pinout

Concept   [Toc] [Top]

Fully software controlled RS232 reception and transmission for PIC16F8x. The microcontroller echoes every received RS232 character back to the RS232 terminal window on the host (i.e. the computer). The HyperTerminal program (Win9x, WinXP) is configured to use the standard settings as shown below.

PCB test board for PIC16F84
using a dot matrix LCD display and a MAX232 for RS232 transmission.


PIC16F84 test board with MAX232
Test setup using asynchronous RS232 connection (RX on PortB0, TX on PortA0). RS232 to USB1.1 connector in the back.


Screen shot of the HyperTerminal Program
showing the start-up message of this RS232 test routine.


Standard RS232 ComPort settings


Project Resources   [Toc] [Top]

Available Microchip PIC Assembler Source Code   [Toc] [Top]

Main File HEX Files
Download assembler source code:
Download Hex File:
The above program needs additional include files (modules) to get successfully assembled: m_bank.asm, m_wait.asm, m_rs096.asm
For those, who are not familiar with interfacing a PIC to the RS232 using a MAX232:   RS232-Interface.pdf   (9.7 kB)


Schematic, Data Sheets and Pinout   [Toc] [Top]

RS232 terminology about DTE and DCE: DTE_DCE_FAQ.pdf

Download ASCII Character Map: ASCII-Map.pdf

You can get the pinout and a description of the various keyboard connectors <here>.


Last updated: 2005/01/16

[Toc] [Top]

If you see only this page in your browser window,
click here
to get the entire site.