Great device, isn't it? :-) > Q1) On my project board, is it OK to hard-wire Vdd and GND to 5 V > and 0 V respectively? Or does the Pickit 2 need to control them? PicKit2 CAN supply +5V (or less) however, you can supply Vdd of your own, PicKit2 will know it and will switch off Vdd supply - you will see a notice when you run the app. > Q2) Can I just hardwire the MCLR pin straight to my 6-pin header, or > do I need this pin to have a specific value for normal operation? (i.e. > is it OK to have it floating when the Pickit2 isn't connected)? If MCLR_OFF is in your config fuse then the PIC will switch on the internal pullup on the MCLR, so you can leave it as it is - and wire it to the PicKit pin as you mentioned. See the datasheet what it says abut MCLR anyway. Also look for ICSP or In Circuit Serial Programming for get the idea what it is all about, how to wire etc. Someone here or in an other thread here mentioned Olin's information about this, it worth to read. > Q3) Will I not be able to use RB6 and RB7 for pushbuttons when I'm > in debug mode? Or will I not be able to use them at all because of the > voltages applied to them by the Pickit2? It's not a voltage (aka DC) but a serial communication in between the chip and the pickit2. I'd suggest not using these at least during the development phase - or experiment phase to learn PIC. The "leftmost" pin as you call it is the PGM pin or LVP pin. You do not need to use that really, but see the datasheet and maybe the programmer guide what to do with the PGM/LVP pin of the PIC. If that is always connected to PicKit2 it is safe to wire it only to that "leftmost" pin... And take a look at the PicKit2 owners manual, the pins are well defined there so the schematics of pickit2 if you need the idea for interfacing with it. Tamas On Thu, Jun 19, 2008 at 12:36 AM, Tom=E1s =D3 h=C9ilidhe = wrote: > > I got the "Pickit2 Debug Express" yesterday. It consists of: > > * Pickit2 device that looks like a small black hockey puck > * A small little prototype board that has an 887 in the middle of > it, plus a few LED's and a variable resistor > > The 887 came shipped with a program on it that lights the LED's in a > sequence. > > I've used the device with MPLAB and I'm happy with it, I can program it > and debug it. I can halt the program and single-step through the > instructions. It's great. > > Given that I'm so happy with this setup, I want to mimic it on my actual > project board. Therefore I've been analysing the connections from the > Pickit2 to the prototype board. There's 6 pins going from the Pickit2 to > the small board. These 6 pins are unmarked on the Pickit2 (no name or > symbol on them). > > On my project board, I'm going to have a 6-pin header for hooking up the > Pickit2 to it. > > Using the continuity tester on my multimeter, I've determined, from left > to right, that the Pickit2 pins go to the following on the 887: > > 1: ?? (Doesn't seem to be connected to anything) > 2: RB6 / ICSPCLK > 3: RB7 / ICSPDATA > 4: GND > 5 Vdd > > > 6: MCLR / Vpp > > Here's my first questions: > Q1) On my project board, is it OK to hard-wire Vdd and GND to 5 V > and 0 V respectively? Or does the Pickit 2 need to control them? > > Q2) Can I just hardwire the MCLR pin straight to my 6-pin header, or > do I need this pin to have a specific value for normal operation? (i.e. > is it OK to have it floating when the Pickit2 isn't connected)? > > Regarding RB6 and RB7, well I was planning on using all the pins on port > B for push buttons. One side of a pushbutton would go to the PIC pin, > and the other would go straight to GND. I would then use the internal > pull-up's so that I don't need a resistor on each of the pushbuttons. > > Q3) Will I not be able to use RB6 and RB7 for pushbuttons when I'm > in debug mode? Or will I not be able to use them at all because of the > voltages applied to them by the Pickit2? (It's no big deal if I can't, > it's just that the internal pull-up's are handy because they negate the > need for extra resistors so that the pin is floating) > > It doesn't appear as if the Pickit2's leftmost pin is connected to > anything, but if anyone knows better then please advise! > > Also if there's any caveats please let me know! Am I on the right track > with this? > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- = Rudonix DoubleSaver http://www.rudonix.com -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist