At 08:43 PM 29/09/00 +1000, you wrote: Piclisters, After reading Roman's useful stuff below please consider this question... Would it be useful to anyone if the adapter below could be used for ALL ICSP PICs with the picstart plus. In other words no need to make up separate adapters for different pinouts. I had this feature in the recently released warpcore driver but I removed it at the last minute as I didn't want people forgetting to turn this mode off to program normally again. I have a similar feature on the WARP-13 as it has a purpose fitted ICSP port. Speak-up if you are interested and I will re-enable this option. -Jim >========================================================== >I posted this before, you are welcome to it. If you don't have >access to a picstart plus programmer and don't want to spend >the $250 AU for one, search for NOPPP "no parts pic programmer" >on the net. It has a few cheap parts and all source code and >description of how it works. > >-Roman > >========================================================== >Hi, don't know if this will help anyone, but on the main >tech.microchip forum I saw a few people asking about using >a picstart plus (PSP) to give in-circuit programming (ICSP) >of applications using flash chips like 16F84 ad 16F877 etc. > >With the help of two guys that posted there who had done it >before I was able to get it happening pretty easy, and thought >I might post details here for reference of anyone (especially >newbies to ICSP) who might want to do this at some point. > >---------------------------------------------- >How to use Picstart Plus to do ICSP (on 16F84) >---------------------------------------------- >Firstly I made a simple header. This is a long-legged 18pin >socket to go into the PSP, with four wires soldered to it. > >Here are the wires: > >* Gnd (Vss) ----- ground wire >* MCLR --R-- 470 ohm series resistor >* RB7 --R-- 470 ohm series resistor >* RB6 --R-- 470 ohm series resistor > >These connect to the same PIC pins on the app, in my case >I designed the app board with the 470 ohm resistors on the >board and a nice plug for the ICSP. > >Important, I used no capacitors on the app on the MCLR >pin. I just used a 68,000 ohm resistor to hold the MCLR >high to 5v when in normal operating mode. This is very simple, >and has low parts cost. > >To program the app, I simply connected power to it (via >a on/off switch) from my regular power source not from >the PSP. The PSP does NOT power the amp or the pic when >programming in this circuit. I connected the ground from >the PSP to the ground of the app's power supply of course. > >One the app was powered, the PSP holds the app in reset >mode as it holds the MCLR pin at 0v. Then I used MPLAB >as normal to program or read the 16F84 in the app. This >works as normal, like when programming a 16F84 in the >socket of the PSP. > >When programming is complete I can just switch the app >power off, unplug the programming plug, and switch the >app power back on to run the app as normal. Quick and easy! > >Just a couple of notes, app's that use a "reset" chip on >the MCLR line may need to make some changes to ensure that >the PSP can draw the MCLR line to 13v very quickly to >ensure good programming. Also my app used the RB7 and RB6 >as inputs, so also using these for the ICSP gave no problems. >I tested adding 10k resistors to both these pins to 0v, >and tested again with the 10k resistors to 5v. Both cases the >ICSP still worked fine. I would guess that means that you >don't need to "buffer" these pins but simply use a 10k >resistor to your circuit and you can still use them as inputs. > >I have programmed the thing with a number of 16F84 chips, >and programmed it a couple of hundred times with NO program >or read failures (unless I forget to switch the app on >before programming!). > >I know this is a long letter and I apologise to the PIC >experts who probably know all of this, just seen a few >newbies ask about ICSP lately and not everyone has the >budget or desire to spend big bucks on ICSP. >YES, you CAN do ICSP with a picstart plus. > >Roman > >-- >http://www.piclist.com hint: The list server can filter out subtopics >(like ads or off topics) for you. See http://www.piclist.com/#topics > >-- >http://www.piclist.com hint: PICList Posts must start with ONE topic: >"[PIC]:" PIC only "[EE]:" engineering "[OT]:" off topic "[AD]:" ad's > > > Regards, Jim Robertson NEWFOUND ELECTRONICS Email: newfound@pipeline.com.au http://www.new-elect.com MPLAB compatible PIC programmers. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: "[PIC]:" PIC only "[EE]:" engineering "[OT]:" off topic "[AD]:" ad's