PICcoder

Hardware

The basic hardware design can be seen below. If you can get hold of a PICDEM FS USB demo board, then thats perfect if not a bare bones version of it can be produced using the circuit diagram below.

USB Hardware

 

 

Please note the Schematic is for a TQFP pin out and will need adjusting if another package is used. Also please connect a 4.7K resistor between RA1 and VDD, to avoid bootup issues. Also USB is very sensitive, ensure that the usb header is placed as close to the pic as possible, to reduce noise effects.

As you can see there is not much to the hardware side of things, most of the complicated electronics is already  in the main body of the PIC, including the pull up resistors which were necessary on the previously microchip USB devices to signal the USB standard being used. The only slight complication with the hardware is that I was using a USB On The Go (OTG) connector, and if you dont want to use one of these you'll find a normal USB connector only has 4 pins avaiable, in which case connect the ground to pin 4 of the usb, instead of pin 5 as shown above. If you have problems locating the USB connectors, try Molex for free samples.

Right Lets get onto the PIC software.