Microcontroller Projects

Using spare parts and free samples


Several years ago I learned that you could receive free samples from microchip.com. So I hooked myself up with a few samples of the PIC16F84, a classic EEPROM programmable microcontroller. Needing a way to program them, I eventually discovered this project. So I was able to build one and connect it to the PC through the serial port and a free programmer available from Microchip. Here is my build of the uJDM:

With the programmer being complete, I tried a few simple projects, such as lighting up LED's and receiving input from switches. I was ready to put the PIC to use in a permanent project. I like making CW QSO's on HF , so I decided to make a simple memory keyer out of it, using a project from the 2000 ARRL Handbook for Radio Amateurs as the main guide. It works well, and is especially helpful for QRP use, since you have to patiently call CQ for a long time! Here are its pictures:

The transistor you see to the left of the PIC chip is a relay that closes the keyer circuit. I simply connected the keyer to the rig by putting the green and black wires in parallel with the hand key.

Written on 6/9/2013
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