LCD SWR Meter Circuit PIC16F877

SWR meter circuit pic16f877 microcontroller with lcd display displays the information on a printed circuit board with 2 × 16, schema diagrams in the C source code library files (adc. c, lcd8 c, swrm. c, timers), and I have 2 different hex code for 16f877a 16f877

SWR meter Features:

Power range 5 to 100 W
Frequency range 1 to 30 MHz
Peak hold display operation for SSB operation.
Several basic screens showing Forward, Reverse, net outgoing power and SWR
Dual bar graph display for forward and reverse power
Large and clear 2*16 character LCD display
Simple two button interface
Hi SWR warning and alarm LEDs
Separate display and SWR bridge units. No antenna cable routing to the meter.

Digital HF Power-SWR Meter

This power-SWR meter is designed for 5 to 100 W ranges, but you can build a heavier measuring bridge and scale instrument for the range you want. The current version of the software provides several basic screens. Scaling and other feature setup parameters are in the software code (no setup menus).

You can install and test the SWR bridge and meter section separately. The SWR Bridge can be tested with a voltmeter and display unit with 0 to 10V psu.

SWR bridge

The critical component is the transformer L1. L1 is a 10-turn bifilar wound on the Amidon FT50-43 core. First twist two 0.4 mm wires together, and then wrap 10 turns evenly distributed on the core. The primary (TX to antenna) is the only wire passing through the core. The wire can be just straight wire or the other end of the grounded braid is fine coaxial. For safety reasons and better performance, it is wise to mount the SWR bridge board in a metal enclosure.

SWR meter Display unit

The display unit is built around the Microchip 16F877A processor and the Solomon LM1125SYLU1 LCD display. The Microchip 16F877 (non-A version) is also supported, but there is no LCD backlight control. The only critical components on the display board are the resistors R2, R3, R5, R6 and IC2. The display unit PCB is designed to allow separation of the pushbutton switches and SWR warning LEDs if your enclosure selection requires it. The backlight current generator fet Q2 may require additional cooling if the operating voltage exceeds 10 VDC.

SWR meter Software

The project was built with the Hi-Tech PICC compiler. It is not strictly ANSI C, but with some work the project can be ported to another environment. This initial test version does not include any user setup functionality. All setup and calibration variables are in the software code. The displays are not carefully planned, they only show the basic information needed. Things may improve in the future.

Source: http://www-diyhome.blogspot.com/