Post by thread:[PIC]: DIP Prototyping

Hi, Having completed my first functioning application with a PIC (C84) - I've got a couple of questions.. Is there any tricks/issues with clockspeed of 4MHz and veroboard construction? Any tricks I should be watching for with respect to noise etc on the veroboard? Anything to watch on the PICs in such constrcution methods. I've already found a couple of "gotcha" tips, but most relate to ensuring I follow my design properly (including the connection of MCLR - instead if leaving it open pending the inclusion of a POR cct that never eventuated) Thanks, Des -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email spam_OUTlistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

Quoting Des Bromilow <.....Des.BromilowKILLspam@spam@CITEC.COM.AU>: > Hi, > > Having completed my first functioning application with a PIC (C84) - I've got > a couple of questions.. > Is there any tricks/issues with clockspeed of 4MHz and veroboard > construction? Regarding to your veroboard, I use them all the time - with an f84/877, and use an external 4 mhz resonator. I haven't had any problems yet, but I haven't tested it for 100% accuracy since I haven't needed it yet. > Any tricks I should be watching for with respect to noise etc on the > veroboard? > Anything to watch on the PICs in such constrcution methods. > Correct me if I'm wrong, but the noise would be more dependant on what's actually in your circuit... not as much the board it's on?? > I've already found a couple of "gotcha" tips, but most relate to ensuring I > follow my design properly (including the connection of MCLR - instead if > leaving it open pending the inclusion of a POR cct that never eventuated) Unless you have an application which requires absolute precision (in both clock speed and logic levels), i think you should be fine with the good ol' veroboard! {Quote hidden}> > Thanks, > Des > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email listservKILLspammitvma.mit.edu with SET PICList DIGEST in the body > ---------------------------------------- This mail sent through http://www.mywaterloo.ca -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam.....mitvma.mit.edu with SET PICList DIGEST in the body

On Mon, 10 Feb 2003, Des Bromilow wrote: > Is there any tricks/issues with clockspeed of 4MHz and veroboard construction? Not that I have noticed in many, many prototyped circuits. > Any tricks I should be watching for with respect to noise etc on the veroboard? Well, don't expect the noise situation to be all that good. Opamps running high gain will hear the strongest local radio station, that sort of thing. Your ADC readings probably won't be good to the last couple of bits. Other than that, no big deal. Dale -- It's a thankless job, but I've got a lot of Karma to burn off. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email EraseMElistservspam_OUTTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

> Any tricks I should be watching for with respect to noise etc > on the veroboard? Like on a real PCB: - keep the wires from osc pins to the xtal short - likewise for xtal -> caps - likewise for caps -> PIC Gnd - don't 'share' the caps -> PIC Gnd wire with anything else - put the 0.1uF decoupler real close to the PIC power pins An do include a fools diode (shorts the power when it is reversed) that can handle the short circuit current from your PSU. Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: http://www.voti.nl consultancy, development, PICmicro products -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestspam_OUTmitvma.mit.edu>

How else does one prototype ? If I had to etch a board for every prototype I would never get a single project finished ;) A few suggestions. 1) By default, most PIC port pins are inputs until configured otherwise. If you are not going to use the pins, and are not going to set them to outputs in code, then it is best to terminate these pins to prevent stray noise interfering with the port pins. Obviously, this is inconvenient when prototyping, but should be a given on any final design. 2) MCLR can be a problem because it can act like an antenna. This usually culminates on the ICSP socket because it puts the MCLR output close to port pin outputs used for ICSP programming. Keep the ICSP pins properly pulled up or down in this scenario. 3) One suggestion I do have in mind is to keep clear of the boards with "lines" of copper, these introduce small unwanted capacitances. Stick with the veroboard that just has copper donuts on the holes, and use Kynar wire to make all interconnections. This stuff is excellent for prototyping. It is silver clad and very low resistance and easy to work with (you use a soldering iron to strip ("melt back") the insulation). Just my own humble opinions on the issue. {Original Message removed}

I find Veroboard-ing takes to long and it's not cheap, so I use those plug in boards (Protobloc I think their called) I have a pile of them fixed to a piece of ply making a working area of about 18" square and it's great for throwing ideas around on. I regularly run CPU's and PIC's at 20MHz and don't have many problems although sometimes you accidentally pull out a wire and it can take a while to find. You can build a block of a circuit, get it working, then add a new block, redesign an existing block until your done - it's great. Not sure you could do RF on them though. But I still use Vero when I can't be bothered to make a PCB or it's a one off for personal use. -----Original Message----- From: Ian McLean [KILLspamianmcleanKILLspamOPTUSHOME.COM.AU] Sent: 10 February 2003 09:25 To: RemoveMEPICLISTTakeThisOuTMITVMA.MIT.EDU Subject: Re: [PIC]: DIP Prototyping - any concerns? How else does one prototype ? If I had to etch a board for every prototype I would never get a single project finished ;) -- http://www.piclist.com hint: To leave the PICList spamBeGonepiclist-unsubscribe-requestspamBeGonemitvma.mit.edu>

> How else does one prototype ? If I had to etch a board for every prototype > I would never get a single project finished ;) I don't know what a "Veroboard" is, but maybe that's a different trade name for what was call "Protoboard" when I bought some. These have strips of sockets on .1 inch centers wired together. Yes, I use them for quick and dirty testing. The biggest problem is not noise, but the limited circuit complexity that can fit without using way too many Protoboards. I have had PICs running with 20MHz oscillators on these many times. There is a template project including photograph at http://www.embedinc.com/pic/hos.htm. > 1) By default, most PIC port pins are inputs until configured otherwise. If > you are not going to use the pins, and are not going to set them to outputs > in code, then it is best to terminate these pins to prevent stray noise > interfering with the port pins. Obviously, this is inconvenient when > prototyping, but should be a given on any final design. I use a system where each I/O pin used by the project is explicitly declared in the project include file. This is done with the /INBIT and /OUTBIT preprocessor commands, in conjunction with the standard port initialization code in the PORT module. The preprocessor, PORT module, and all the related stuff is available at http://www.embedinc.com/pic for free. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: To leave the PICList TakeThisOuTpiclist-unsubscribe-requestEraseMEspam_OUTmitvma.mit.edu>

Olin, Veroboard (at least in the UK), is a form of fibreglass/composite material board with parallel copper strips running down the length and pre-drilled usually with 1mm holes, though I have seen other sizes in the past. Ideal for transferring your masterpiece directly from your "Protoboard" to a more permanent home. {Original Message removed}

Olin Lathrop wrote: >> How else does one prototype ? If I had to etch a board for every >> prototype I would never get a single project finished ;) > I don't know what a "Veroboard" is, but maybe that's a different trade > name for what was call "Protoboard" when I bought some. These have > strips of sockets on .1 inch centers wired together. A Veroboard is basically a PCB with tracks running straight across the board with holes punched at 0.1in centers. A Protoboard is also known as a "Breadboard" or "Solderless Prototyping Board" IIRC. > Yes, I use them for quick and dirty testing. The biggest problem is > not noise, but the limited circuit complexity that can fit without > using way too many Protoboards. I have had PICs running with 20MHz > oscillators on these many times. There is a template project > including photograph at http://www.embedinc.com/pic/hos.htm. Nice one. I've had Ubicom SXes running at 50MHz in Turbo mode on a breadboard before. Anyone prototyped anything faster? Later. -- Phil. RemoveMEphilpemTakeThisOuTdsl.pipex.com http://www.philpem.dsl.pipex.com/ -- http://www.piclist.com hint: To leave the PICList piclist-unsubscribe-requestEraseME.....mitvma.mit.edu>

On Mon, 2003-02-10 at 17:36, Philip Pemberton wrote: > A Veroboard is basically a PCB with tracks running straight across the board > with holes punched at 0.1in centers. I think Veroboard is the tradename for a common brand of stripboard. -- ------------ Alex Holden - http://www.linuxhacker.org ------------ If it doesn't work, you're not hitting it with a big enough hammer -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads