As number of published posts has increased a more general approach is needed for circuit’s prototyping. Instead of building each individual design to validate its operation why not to construct a simple PIC16F877A based Development Board. Current design have all the necessary ingredients for a basic board, including 10 Segment LED bar graph, 2X16 LCD Display, 3×4 Keypad. Also I’m planning to add some communication capabilities by adding I2C devices like PCF8591 A/D D/A converter and real time clock with battery backup. For anyone who wants to go even further and obtain more advanced hardware here is a link to some interesting development boards. The prototype as usual was built on a standard 830 breadboards, 3 were used. All recent projects can be built and tested with this board. I’ve also included a simple test program code in this post that can be downloaded at the bottom of the page. (See similar board here – AD9850 Signal Generator Project)
The board doesn’t have built in programming capabilities so you’ll need some sort of programmer like PicKIT2,3 or other compatible devices to download the code into microcontroller. Few words about the test software. Press any key to display its binary code on LED bar graph connected to PORTD.10K Potentiometer is connected to analog channel 1, rotate it to display converted voltage values on PORTC. LCD Display data lines are also connected to PORTD and PORTE controls display Enable and RS lines. See schematic for more details. Assembly code is here.