Schaer+ Programmer using PIC12F629 microcontroller


Schaer is a generic programmer circuit capable of uploading and downloading firmware to/from several electronic devices like microcontrollers and eeproms. This and other programmers came to my attention when I was working in CAMBADA, the robotic soccer team from the University of Aveiro, and since all other programmers available there were too expensive for me to buy or build, I decided to build one that was simple and cheap!

schaer whiteboard

This programmer has given me lots of trouble with high capacity PICs and I decided to abandon the project and build a ICD2 clone for MPLAB. What rests here are just the remains of the project.

Design and Implementation

I can’t remember where I found the first schematic on the web but after testing it in a white board I decided it was best to try a definitive solution on a PCB. The circuit is very straightforward: it gets its control signals from the parallel port and sends it to the PIC being programmed. It needs one power supply of at least 15V and generates its 13V and 5V with 78XX regulators.


Schematic schaer

The schematic is a copy of the original schematic found on the web. At the top of this page is the first implementation on a prototype white board.


For more detail: Schaer+ Programmer using PIC12F629 microcontroller

About The Author

Ibrar Ayyub

I am an experienced technical writer holding a Master's degree in computer science from BZU Multan, Pakistan University. With a background spanning various industries, particularly in home automation and engineering, I have honed my skills in crafting clear and concise content. Proficient in leveraging infographics and diagrams, I strive to simplify complex concepts for readers. My strength lies in thorough research and presenting information in a structured and logical format.

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