Some time back, I wrote about starting some work on microcontrollers, a move to try to re-ignite the long gone cold knowledge of electronics that was part of my Bachelors degree, but which I did nothing with for years. Anyway, I settled on the Microchip PIC 16F84A since there seemed to be a lot of projects and sample circuits available on the Internet that use this little controller. In order to use the microcontroller, one must first build or acquire some means to download a program into the controller's tiny on-board flash RAM in the first place. My first attempt, using the
PicBlaster design which was really easy to build... was unsuccessful. I figured that it was because it was a serial port design. Problem is it seems that simple serial port programmers like the PicBlaster depend on the serial port voltage levels being above 12V to work, so tough luck if your serial port doesn't put out the right voltages. It seems that modern PCs, especially laptops can output voltages as low as 8.6V, which is no good for such purposes. So I had to find some other design, preferably one that didn't use the serial port. Enter the
NOPPP, deceptively called the "No Parts PIC Programmer", despite the fact that the main circuit itself has some 17 components, but that's another story.
Woo-hoo! All done! The good thing about the NOPPP is that it is a powered parallel port programmer. That means it is not dependant on the serial port, nor whatever voltage it is putting out. The NOPPP has circuits to ensure that the >12V programming voltage is properly generated and applied to the MCLR pin. Now to try it out... To cut a long story short... It doesn't work either! Something to do with modern PCs being too fast. Grrrr!!!
