The path of least resistance would be to build up one of the circuits that uses an external 13 volt supply. It only takes a few transistors. As other have alluded to, the voltage on the RS232 port varies all over the map. Once upon a time, you could pretty much count on +/- 15 volts. Nowadays you never see that. I did a survey a couple of years ago before Craig did the PIC-EL, and the most common voltage was 0.9! 9 was also fairly common, but so was everything in-between. The tricky one is !MCLR which needs to go from around zero to around 13 fairly quickly. The other are all CMOS logic levels. Of course, you still need to get between the serial port's +/- something to the PIC's around 0-5. Take a look at the Covington design which probably inspired thousands of PIC hobbyists, and at the various David Tait designs, which outfitted pretty much all the rest until recent years when things like the Wisp came along. They all do pretty much the same thing. There is either a transistor or a gate on each line to do the translation. Another thing to keep in mind is that NONE of the simple designs will work with a USB to serial converter. If you ever intend to upgrade your PC to some newer model without a real serial port, then something like the Ez-Prog or the Wisp would probably be a better choice. These are a little more expensive than the really simple designs, but they have the advantage that they are likely to work with a future PC. The simple designs WILL NOT work with a USB-Serial converter. Full stop. Will not work. Keep that in mind. And it would be hard to accuse either the Ez-Prog or the Wisp of being expensive. The parallel port designs like Covington's NoPPP or the Tait ParPIC are a little simpler than the serial port designs, and parallel ports are a little more common than serial ports these days, but I think the handwriting is on the wall for parallel ports, too. So there is some more data on the simple/not so simple, bought/built equation. --McD ----- Original Message ----- From: "Dionis Teshler" To: Sent: Wednesday, August 17, 2005 8:24 AM Subject: Re: [PIC] Programmer doesn't burn all of the program > Thank you very much for the in depth reply. I measured the voltage on the > MCLR! line using the IC-Prog "Test Hardware" mode and I got 8.2v, also I > noticed that when I turn on the MCLR!, Clock and Data pins together, it > doesn't even have enough current to light the LEDs. Thus, can somebody > tell me how can I hook up an external power source to the existing circuit > without much modification so the circuit (mostly the Zener diodes) would > have enough current and voltage? > The really wierd thing is that it actually programs up to address 0006h or > 0009h and stops. > > Dionis > > >>From: "John J. McDonough" >>Reply-To: "Microcontroller discussion list - Public." >>To: "Microcontroller discussion list - Public." >>Subject: Re: [PIC] Programmer doesn't burn all of the program >>Date: Tue, 16 Aug 2005 17:46:27 -0400 >> >>Dionis >> >>First, you will hear a lot of "Get a proper programmer", "toss the 84", >>etc. Lots and lots and lots of people got started on simple programmers an >>16F84's. Personally, if you are not already pretty comforatble with >>microcontrollers in general, I would suggest starting with a 84. However, >>once you get comfortable with reading the data sheet and understanding it, >>toss the 84 for something better/faster/cheaper. This gets to be a bit of >>a problem between programmers and programming software, but there are a >>lot of choices out there. Don't be put off by those who say you HAVE to >>use a 16F88 or a 16F628 or some 18F thing or some 30F thing. Everyone has >>their own prejudice, but the 16F84 is a perfectly good part, and it has >>the advantage that it is easier to learn than most of the others. Be >>aware that once you get much beyond flashing a LED almost any other part >>has some advantage or another, and they are almost all cheaper. So don't >>get married to the 84, use it to learn the basics then move on. >> >>That being said, be aware that there are a LOT of really bad 16F84 >>examples on the web. Look for more recent examples, especially examples >>by members of the PIClist. Generally you will find better quality code. >>A lot of the older examples out there do very stupid things. >> >>As far as you programmer, I do have some reservations. As others have >>mentioned, something like the Wisp will make your life a lot easier. But >>most people, by far, got started on the simple programmers, so it isn't >>impossible. One thing that concerns me, though, is that the design you >>are using derives the +13 from the serial port. This is not a good idea. >>Programmers that do not require an external 13 volt supply are almost >>always a problem to get going, the exception being more expensive examples >>like the ICD2. >> >>Before you do anything, get someone with a scope to have a peek at the >>!MCLR line during programming. If that line doesn't goto 13 volts you're >>not going to get the part programmed. As best I can tell, no two PC >>serial ports are alike, so trying to derive 13 volts from that port is a >>crap shoot. So, once you KNOW that !MCLR is getting to 13 volts, then >>lets move on to the next thing to check. If it doesn't get to 13 volts, >>the answer is another programmer or another PC. >> >>--McD >> >> >> >>----- Original Message ----- From: "Dionis Teshler" >>To: >>Sent: Tuesday, August 16, 2005 8:52 AM >>Subject: [PIC] Programmer doesn't burn all of the program >> >> >>>Hello all, >>>I am pretty new to microchip programming, so forgive me for maybe being >>>kind of slow. >>>I built this programmer: >>>http://www.talkingelectronics.com/FreeProjects/MultiChipPgmr/MultiChipPgmr-P2.html >>>and I am using IC-Prog 1.05D >>>The problem is that I always get verification errors after burning. I am >>>on JDM with all of the options inside "communication" unchecked. I am >>>programming on win XP and using PIC 16F84A with the icprog XP driver. The >>>thing is that I started with 10 I/O delay and it programmed only on >>>0000h, after that I tried lowering the setting and is started programming >>>up to 0006H with the lowest delay. The rest remains empty. >>>How can I fix this problem? >>> >>>_________________________________________________________________ >>>FREE pop-up blocking with the new MSN Toolbar - get it now! >>>http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/ >>> >>>-- >>>http://www.piclist.com PIC/SX FAQ & list archive >>>View/change your membership options at >>>http://mailman.mit.edu/mailman/listinfo/piclist >>> >> >> >>-- >>http://www.piclist.com PIC/SX FAQ & list archive >>View/change your membership options at >>http://mailman.mit.edu/mailman/listinfo/piclist > > _________________________________________________________________ > FREE pop-up blocking with the new MSN Toolbar - get it now! > http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/ > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist