---- START NEW MESSAGE --- Received: from cherry.ease.lsoft.com [209.119.0.109] by dpmail10.doteasy.com with ESMTP (SMTPD32-8.05) id A77A8F000D8; Fri, 30 Jan 2004 06:17:30 -0800 Received: from PEAR.EASE.LSOFT.COM (209.119.0.19) by cherry.ease.lsoft.com (LSMTP for Digital Unix v1.1b) with SMTP id <14.00CC4BE7@cherry.ease.lsoft.com>; Fri, 30 Jan 2004 9:17:18 -0500 Received: from MITVMA.MIT.EDU by MITVMA.MIT.EDU (LISTSERV-TCP/IP release 1.8e) with spool id 9059 for PICLIST@MITVMA.MIT.EDU; Fri, 30 Jan 2004 09:17:11 -0500 Received: from MITVMA (NJE origin SMTP@MITVMA) by MITVMA.MIT.EDU (LMail V1.2d/1.8d) with BSMTP id 9532; Fri, 30 Jan 2004 09:15:24 -0500 Received: from sark.cc.gatech.edu [130.207.7.23] by mitvma.mit.edu (IBM VM SMTP Level 430) via TCP with ESMTP ; Fri, 30 Jan 2004 09:15:24 EST X-Comment: mitvma.mit.edu: Mail was sent by sark.cc.gatech.edu Received: from cleon.cc.gatech.edu (cleon.cc.gatech.edu [130.207.9.12]) by sark.cc.gatech.edu (8.12.10/8.12.8) with ESMTP id i0UEFRhZ021469 for ; Fri, 30 Jan 2004 09:15:27 -0500 (EST) Received: (from byron@localhost) by cleon.cc.gatech.edu (8.12.10/8.12.8) id i0UEFQ1G019593 for PICLIST@MITVMA.MIT.EDU; Fri, 30 Jan 2004 09:15:26 -0500 (EST) References: <000201c3e708$d9304600$6501a8c0@Novalin> <005801c3e713$0ad17580$3822a250@webspeed.dk> <006201c3e72f$d2916910$080044c0@BrianBoru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.1i Message-ID: <20040130141526.GB18549@cleon.cc.gatech.edu> Date: Fri, 30 Jan 2004 09:15:26 -0500 Reply-To: pic microcontroller discussion list Sender: pic microcontroller discussion list From: Byron A Jeff Subject: Re: [PIC:] Programming interface To: PICLIST@MITVMA.MIT.EDU In-Reply-To: <006201c3e72f$d2916910$080044c0@BrianBoru> Precedence: list X-RCPT-TO: Status: U X-UIDL: 371856507 On Fri, Jan 30, 2004 at 07:51:46AM -0500, John J. McDonough wrote: > Somehow or another Andre apparently made a reply that I didn't see, although > I did see his reply to his own reply. Unfortunately I don't know what he > said. > > Anyway .. a couple of comments. An 877A is not an 877. There is lots of > free software to program the 877, not so the 877A. As best I can tell, > software that does program the 877A requires a specific, usually expensive, > programmer. Not really. There are free programming systems for tait style programmers. ic-prog and odyssey come to mind immediately. There are a couple of minor differences what are just enough to screw up the process: 1) In order to speed programming, all of the newer PICs incorporate data buffers and program in blocks of 4 or 8 words. The interesting thing is that while there's virtually no change for self programming, other than making sure that you load an entire block before writing, that with the external programmer you must do 4 or 8 load/increment address commands before issuing a a programming command. But the advantages are so obvious that it's worth it. I'm decided to bite the bullet and spend a half day getting picprg up to speed on the newer parts. Since my student has worked out a Windows port, putting the two together should result in a up to date programming system that's multi platform, which only Wouter can also boast. 2) The second which is slightly more problematic is the fact that the cost of the faster programming speed is that most of the newer pics begin programming commands are self timed. So the programming software must issue a end programming command. But it's worth it. With the 16F87XA at 5V the programming speed is up to 32 times faster than the 16F87X parts (8 words @ 1ms in a single write vs. 8 words @ 4ms (max) each) . > > I would suggest that you consider whether 5 volt programming is really a > requirement. Virtually any of the popular designs for cheap programmers > will work with the 877 in HVP mode, although the ones that work without > hassle generally require a 13.8 volt supply rather than trying to get the > high voltage from your serial port. It doesn't really matter one way or the other. HVP is almost always better because you retain use of RB3. The most productive system I've found so far is installing a bootloader into the part, then using the bootloader from then on to load programs. Wouter's Wloader (http://www.voti.nl/wloader) is excellent for the task. And wloader works through your serial port, only requires a single I/O pin, and you get to choose the pin instead of it being selected for you. The default is RE2 which is way out the way of most I/O activity. > > Now maybe you really need an A, and maybe you really need LVP, and if this > is the case, I would prepare for spending a few dollars. But if you can > come up with 13.8 volts (nothing wrong with batteries), you really don't > need low voltage programming, and you can live without the A, then there are > dozens of very cheap alternatives and you will be astonished at how simple > it is. In fact, even the most lame junkbox is likely to contain all you > need. > > Any of the common F84 designs can be pressed into service by simply > replacing the 18 pin socket with a 40 pin. There are only 5 pins connected, > and you just match up pin names. I happen to prefer the Covington design, > but any of the Tate designs is just fine, too. There must be a dozen > designs you can build for under 10 euro. Tate's FPP program will work with > most of them, and is very convenient to use. Depending on what you are > doing, you may want to read Microchip's ICSP guide and build up a circuit to > allow programming in your target circuit. Not having to yank the part out > of the target to put it in the programmer during debugging is a huge > convenience, and it ain't rocket science. Agreed on all of this. And there are free programming software (ic-prog, odyssey Agreed on all of this. And there are free programming software (ic-prog, odyssey. and picprg which I plan to update soon) that will program the newer parts. BAJ -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listserv@mitvma.mit.edu with SET PICList DIGEST in the body .