7. Programming using the PICkit 3
Warning: Using a PICkit to program the P-Star will permanently erase its USB bootloader, so you will not be able to program it over USB using the Pololu USB Bootloader Utility. It will also erase the serial number of the device.
The PICkit 3 from Microchip is a hardware debugger and programmer for PIC microcontrollers that can be used to program the P-Star.
The PICkit 3 has a female header with six pins. Five of these pins need to be connected to the P-Star in order to program it:
- Pin 1 of the PICkit 3, which is indicated with a triangle on the PICkit’s case, connects to the P-Star’s MCLR pin.
- Pin 2 connects to VDD.
- Pin 3 connects to GND.
- Pin 4 connects to RB7 (also known as PGD).
- Pin 5 connects to RB6 (also known as PGC).
- Pin 6 should be left unconnected.
In addition to making these connections, the P-Star must also be powered (the PICkit 3 does not supply power).
The picture below shows one way to connect a P-Star to a PICkit 3. An upwards-pointing 1×4 male header is soldered to VDD, GND, RB7, and RB6. These pins are connected to the PICkit 3 with male-female premium jumper wires. The MCLR pin is connected to the PICkit 3 through the breadboard and a male-male premium jumper wire. The PICkit 3 must be connected via USB to a computer, and the P-Star needs to be powered either from its USB port or from the VIN pin. The picture below shows a P-Star 25K50 Micro, but the same setup could be used with P-Star 45K50 Mini as well, since the 5 ICSP pins are in the same position.
The P-Star 25K50 Micro connected to a PICkit 3 programmer and a reset button.
Another option for connecting a P-Star to a PICkit is to solder upwards-pointing header pins on all five programming pins, as shown below. The PICkit 3 can then be directly connected to this five-pin header, or it could be connected through a set of male-female premium jumper wires. This configuration of header pins prevents the MCLR pin from plugging directly into a breadboard, but it could still be connected via a jumper wire.