Overview

Back in 1985, I used to work on micros - it was the Z80 then. Years later, in 1997, I decided to get back into micros and found the technology had progressed a lot. Flash based micros were now available. So I picked a Motorola micro used in the Mini-board. It was hard to source and I finally settled on the PIC 16C84. After getting used to its weird architecture, I built a few projects around it. Over the years, I have moved from the 16C84 to the 16F876 and now to the 18F4550 in 2009, staying within the PIC family all the time. Here are some of the PIC projects of various vintages.

Current Techniques

Every time I return to PIC projects, usually after a long break, I usually spend some time catching up to the latest in electronics and changing the way I do projects. In 2009, I found quite a few different ways to make it easier and more interesting to build PIC projects.

Experiments with Cree LEDs

I built a simple 18F4550 based circuit to measure how hot a Cree LED gets with varying driving currents.

The circuit above uses a slow PWM frequency of a few KHz. I may require a much faster PWM. So I built an 8 channel PWM with 100 step resolution and a frequency of 25 KHz.

IR Receiver

An old circuit built around the 16C84 and a VB front-end. The IR receiver receives and decodes signals from a Sony IR remote control and sends the codes received to a serial port on a PC. A VB program then displayed the codes. Another project used the same hardware to receive signals from most IR remotes and sent information on the pulse train to the PC serial port. A VB program then displayed it in a fashion mimicking an oscilloscope.

IR Analyzer

The next version built around the 18F876 and a java front-end. The IR Analyser uses a PIC based IR send/receive circuit and a java front-end running on a PC to help analyse the signals sent by IR remotes. These signals can be studied as a waveform and their parameters and coding scheme deduced from it.

Driving VFDs

Driving vacuum fluorescent displays using a PIC is another project described here. This also illustrates a java applet used to publish timing diagrams on the web. Another java application described here is handy for publishing PIC assembly listings on the web.

Last updated on 10-July-2010

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