RS232 Communication Test Routine
(1)
fully software controlled RS232
transmission and reception for PIC16F84
Table of Contents [Toc]
Concept
Specifications
Project Resources
Available Microchip PIC
Assembler Source Code
Concept [Toc] [Top]
Fully software controlled RS232 reception and transmission for
PIC16F8x.
Display of received ASCII characters sent from PC via RS232 and
their corresponding decimal value on the LCD. Microcontroller
sends feedback of received characters back to the terminal
window. When the PIC terminal is idle, it sends a status message
'@' to the PC every 2.75 seconds.
Shows the implementation and function of the modules m_wait.asm,
m_rs096.asm, m_lcd.asm and m_lcdv08.asm on the PIC 16F84.
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PCB test board for PIC16F84
using a dot matrix LCD display and a MAX232 for RS232
transmission.
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PIC16F84 test board with MAX232
Test setup using LCD display on PortB and asynchronous
RS232 connection (RX on PortB0, TX on PortA0). RS232 to
USB1.1 connector in the back.
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LCD display after reset
shows
welcome screen of this program.
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LCD display output during operation
after sending 'A' from the PC across the RS232 line.
The character sent is echoed back to the PC by the
microcontroller.
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Screen shot of the HyperTerminal
Program
showing the start-up message of this
RS232 test routine.
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Specifications [Toc] [Top]
| Processor: |
Microchip PIC 16F84 |
| Clock Frequency: |
4 MHz crystal |
| Throughput: |
1 MIPS |
| RS232 Baud Rate: |
9600 baud, 8 bit, no parity, 1 stopbit |
| Code Size of entire
Program: |
approx. 566 instruction words |
| Acquisition
Methodology: |
Interrupt-based RS232 data acquisition, with
LCD display output and RS232 echo during normal
operation |
| Required Hardware: |
MAX 232, dot matrix LCD display |
| Required Software: |
RS232 terminal software (or Excel 97 RS232
Debug Interface) |
Project Resources [Toc] [Top]
Available
Microchip PIC Assembler Source Code [Toc] [Top]
| Main File |
HEX Files |
Download assembler source
code:
commtest1.asm |
Download Hex File:
commtest1.hex |
| 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) |
Download ASCII Character Map: ASCII-Map.pdf
Last updated: 2005/01/16
[Toc] [Top]