Pickt2 more than 20 pins?

Discussion in 'Embedded Systems and Microcontrollers' started by powzoom, Jul 17, 2009.

  1. powzoom

    Thread Starter Active Member

    Jan 18, 2009
    The pickit2 says it supports devices larger than 20 pins but how would I program them since the programmer only has a 20pin socket? There doesn't seem to be info about it in the documentation.
  2. blueroomelectronics

    AAC Fanatic!

    Jul 22, 2007
    You need to connect them using the ICP pins (you don't use the demo board), typically MCLR, RB6 & RB7
  3. bertus


    Apr 5, 2008
  4. blueroomelectronics

    AAC Fanatic!

    Jul 22, 2007
    Nice site bertus, here's the picture from that site.
  5. Vaughanabe13

    Active Member

    May 4, 2009
    To explain this a little bit:
    The PICKIT2 doesn't need the demo board to program a micro. That demo board is mostly used for beginners and small projects. The programmer can be connected to any PIC in a circuit, and you only need to run 5 wires between the two. Power and ground are self explanatory. Vpp is called the Programming Voltage and the PICKit uses it to tell the PIC it is going to reprogram. The PICKIT2 sends around 12-13V to the PIC on this pin when you start programming, which is why you need the diodes connected to your circuit's power supply. This prevents the 12V signal from damaging your circuit's power supply. You don't need them if your circuit is being entirely powered by the PICKIT2. The other two wires you need are Data and Clock. Data is usually labeled "PGD" on your PIC's datasheet. Clock is usually labeled "PGC." Just hook those wires directly to each other.

    The resistors in the bottom of the picture are unnecessary AFAIK. They look like pull up resistors, although I can't read German. I don't see why they would need PU resistors for those pins. Also the switch is used to connect the MCLR/VPP pin to ground for a reset, which is also optional. You could replace that with a 10K resistor straight to 5V.
  6. blueroomelectronics

    AAC Fanatic!

    Jul 22, 2007
    The resistors at the bottom were added in a effort to keep from loading the PGC/PGD lines when using those pins for other functions/circuitry after programming. Also keep the programming cable very short else you're likely to get programming errors.

    The diode from power to VDD is unnecessary and the VPP diode (1N4148) is optional but recommended.