Microelectronics | Serial PIC Programmer

Synopsis

I've found the RCD programmer to be a very good serial port programmer for PIC microcontrollers. The schematic diagram belongs to FENG3, and can be found by following the RCD Programmer Internet page. The circuit is extremely useful for programming generic PIC microcontrollers such as PIC16F84(A). In addition, it is very compact. The circuit draws power directly from the serial port of a desktop computer or a laptop.

Schematic Diagram

Let's inspect the schematic diagram.

While the circuit is easy to understand, the author (FENG3) gives a lot of technical details on his site, so better check the official documentation for a better understanding of the principle of operation.

Construction and Pictures

I used only spare parts for this project, and I made the PCB at home, after FENG3's suggested circuit layout. I drew the tracks with a permanent marker and then etched the PCB with nitric acid (HNO₃). Then I've cleaned the permanent marker with isopropyl alcohol.

This is the result. Resistors are Romanian-made and are of type RPM (metal deposit). Diodes are also from an old stock of Romanian components. I've recovered the green LED from a dead hard disk drive.

Only the machine socket is new. While not the best component choice for frequently swapped integrated circuits, a precision machine socket ensures a good contact with the pins of the microcontroller.

Now, programming a PIC16F628 microcontroller. The LED illuminates during the programming operation, and the circuit works as expected.

Thank you for reading this page, and I hope you found it useful.