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Hey all, Is it possible to create a pcb for a single chip 68hc11 system using only one side of the pcb? To expand, I have a design with one 68hc11, one max432(?) serial converter, crystal, caps, and jumpers. Just a simple, basic, functional setup.(i.e.-it works on my perf-board setup) I ask because my 2-sided pcb construction skills are not good and have not worked in the past. I dont want to waste the time laying out the pcb for oneside if it is not possible. And I cant keep doing it on a perf-board, there are about 100 short wires that need soldering on each side!! Thanks for any advice, bob d. |
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PCB layout question
Started by ●March 14, 2003
Reply by ●March 14, 20032003-03-14
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Hi Bob, Don't even think of building your own PCBs. You can get prototype pcbs made way cheaper and Wa-a-a-a-a-a-y more reliably than you could ever do so yourself, even if you were to value your time at $0/hr. We have used www.apcircits.com many times with good success. Bob Furber > Is it possible to create a pcb for a single chip 68hc11 > system using only one > side of the pcb? > > To expand, I have a design with one 68hc11, one max432(?) > serial converter, > crystal, caps, and jumpers. Just a simple, basic, functional > setup.(i.e.-it > works on my perf-board setup) > > I ask because my 2-sided pcb construction skills are not good > and have not > worked in the past. I dont want to waste the time laying out > the pcb for > oneside if it is not possible. And I cant keep doing it on a > perf-board, > there are about 100 short wires that need soldering on each side!! > > Thanks for any advice, > bob d. > > ------------------------ Yahoo! Groups Sponsor > ---------------------~--> > Get 128 Bit SSL Encryption! > http://us.click.yahoo.com/xaxhjB/hdqFAA/xGHJAA/dN_tlB/TM > ---------------------- ---- > -------~-> > > To unsubscribe from this group, send an email to: > > > ">http://docs.yahoo.com/info/terms/ > |
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Reply by ●March 14, 20032003-03-14
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> Don't even think of building your own PCBs. You can get > prototype pcbs made way cheaper and Wa-a-a-a-a-a-y more > reliably than you could ever do so yourself, even if you > were to value your time at $0/hr. We have used > www.apcircits.com many times with good success. Thanks for the info (www.apcircuits.com). It looks like a good service, but is beyond what i need. I am a student/hobbiest. I only need one or 2, (maybe more in future) boards made. My method for single side pcb is very effective and works well for me. I use Eagle Cad layout, with the "iron-on" method. Purchasing the required items costs: <$5.00 for copper plated pcb $10.00 for several sheets of the special hp glossy paper $3.00 for etching solution Have iron, and access to good laser printers, drill etc. EagleCad - free version for linux It is alot cheaper then apcircuits,...but if i ever need production runs, i will keep them bookmarked. Thanks, (anyone tried a single sided 68hc11 board?) bob d. |
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Reply by ●March 14, 20032003-03-14
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On Fri, Mar 14, 2003 at 11:54:03AM -0600, MAOS wrote: > > Don't even think of building your own PCBs. You can get > > prototype pcbs made way cheaper and Wa-a-a-a-a-a-y more > > reliably than you could ever do so yourself, even if you > > were to value your time at $0/hr. We have used > > www.apcircits.com many times with good success. > > Thanks for the info (www.apcircuits.com). It looks like a good service, but is > beyond what i need. I am a student/hobbiest. I only need one or 2, (maybe > more in future) boards made. As a student its good to be frugal, but "penny wise, pound foolish" also applies. Part of the learning process is to know when to delegate to others. > My method for single side pcb is very effective and works well for me. I use > Eagle Cad layout, with the "iron-on" method. Purchasing the required items > costs: > <$5.00 for copper plated pcb > $10.00 for several sheets of the special hp glossy paper > $3.00 for etching solution Two 3"x5" double sided PCBs with 100 holes is $65.50 at http://www.apcircuits.com. With your supplies you are already 1/3rd into that. If your time is worth $1/hour you won't break even and you won't have as good of a PCB. Likely later you will find a bad trace on the board you make. And that bad trace might take 20 hours to find. Spend more time on your PCB layout. Add jumpers for CPU modes. Add pads and traces for easy debugging probes. Bring out all the port pins, even the ones you are not using this time. Add the RS-232 buffers and connectors. A "prototype area" can cost a lot extra for the difficulty in drilling many holes. If you put holes 300 mils apart on one axis and 100 mils the other way you have what is needed to put most thru hole parts down, and in a pinch can put resistors and capacitors in the same spacing. Once you commit to having a board made it doesn't cost much, if anything, to add this stuff, and can save loads of time later. > It is alot cheaper then apcircuits,...but if i ever need production runs, i > will keep them bookmarked. > > Thanks, (anyone tried a single sided 68hc11 board?) > bob d. Yes, I have. But it matters a lot more as to what you are actually putting on the board and how much time you will spend to make it fit. If your time is so cheap I don't understand what you are opposed to a mere 100 wires. I actually prefer to "wire wrap" with a soldering iron on protoboard pads rather than use expensive wire wrap sockets. A PLCC-52 thru-hole socket is pretty easy to hook up that way. I typically use HC11E's. There used to be a number of sources of 68HC11 SBC's at the $65 to $99 price range. Sounds like a good solution for you. Maybe you should consider producing one? -- David Kelly N4HHE, ===================================================================== The human mind ordinarily operates at only ten percent of its capacity -- the rest is overhead for the operating system. |
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Reply by ●March 14, 20032003-03-14
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> If your time is so cheap I don't understand what you are opposed to a > mere 100 wires. I actually prefer to "wire wrap" with a soldering iron > on protoboard pads rather than use expensive wire wrap sockets. A > PLCC-52 thru-hole socket is pretty easy to hook up that way. I typically > use HC11E's. > > There used to be a number of sources of 68HC11 SBC's at the $65 to $99 > price range. Sounds like a good solution for you. Maybe you should > consider producing one? I appreciate everyone's help. I will go ahead and try to develop the pcb myself. I know that i have put a few dollars in supplies already. Thats basicly the point. ... I get roughly $20 or less a week to spend on myself after bills and childcare. If i could drop $60-100 on a hobby i would,...its just not possible at this time. (yah, cry me a river) I dont have money to go out so i spend my spare time doing homework and studiying my electronics/programming addictions. Plenty of time to "do-it-myself". Thanks for the advice though, i will look to see what i need to get to do a wire wrap solution, till then i'll see how eagle cad works out, ...I will post my pcb layout if it works. :) End transmission: bob d. |
Reply by ●March 15, 20032003-03-15
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I am not familiar with the low-cost version of Eagle that you refer to,
but I use regular Eagle for my embedded design work and have a lot of respect for it. Just as in trying to design with double sided boards, you will find that as the component density goes up, the topological complexity of the design goes up and you rapidly reach a point that your traces become "trapped" (i.e., "you can't get there from here"). Your main problem will be the requirement to run power and ground traces intermixed with signal traces. (For that reason, most of my designs now use four-layer boards). A way to deal with that is to use power and ground "buses" run above or below the board level. This can be accomplished by inserting small standoffs at points where power and ground are needed and then running bus wire to tie them together. (Try to think of signal traces as streets and local roads, power as electrical power lines, and ground as buried water mains). Buy yourself a bag of Keystone PC Test Points, a spool of about #22 tinned bus wire, and a spool of #22 insulated sleeving). You can also purchase strips of bus bar and cut and bend them to your needs. I think a company named Rogers used to make these. Bypass capacitors can be connected from standoff to standoff so that they do not take up board space. Alternately, use insulated, solid conductor, hook-up wire, cut to length and strip a bit from each end. If you use bare wire and sleeving, I recommend cutting the sleeving with a razor blade. Cutting with ordinary diagonal cutters mashes the ends and makes it a bitch to thread the sleeving over the wire. DigiKey P/N ----------------- 5000K-ND Test point (Red) 5001K-ND Test point (Black) Another secret weapon is to use "zero ohm" resistors to "bridge" over other traces and route your way out of topological traps. (Imagine the interstate highway system without overpasses and cloverleaf intersections). Take advantage of as many "real" resistors and other components as you can to route signals out of trap areas. Happy prototyping, Bob Smith --- Avoid computer viruses, Practice safe hex --- -- Specializing in small, cost effective embedded control systems -- http://www.smithmachineworks.com/embedprod.html Robert L. (Bob) Smith Smith Machine Works, Inc. 9900 Lumlay Road Richmond, VA 23236 804/745-1065 ----- Original Message ----- From: "MAOS" <> To: <> Sent: Friday, March 14, 2003 5:14 PM Subject: Re: [m68HC11] PCB layout question > > > If your time is so cheap I don't understand what you are opposed to a > > mere 100 wires. I actually prefer to "wire wrap" with a soldering iron > > on protoboard pads rather than use expensive wire wrap sockets. A > > PLCC-52 thru-hole socket is pretty easy to hook up that way. I typically > > use HC11E's. > > > > There used to be a number of sources of 68HC11 SBC's at the $65 to $99 > > price range. Sounds like a good solution for you. Maybe you should > > consider producing one? > I appreciate everyone's help. I will go ahead and try to develop the pcb > myself. I know that i have put a few dollars in supplies already. Thats > basicly the point. ... I get roughly $20 or less a week to spend on myself > after bills and childcare. If i could drop $60-100 on a hobby i would,...its > just not possible at this time. (yah, cry me a river) > > I dont have money to go out so i spend my spare time doing homework and > studiying my electronics/programming addictions. Plenty of time to > "do-it-myself". > > Thanks for the advice though, i will look to see what i need to get to do a > wire wrap solution, till then i'll see how eagle cad works out, ...I will > post my pcb layout if it works. :) > > End transmission: > bob d. > To unsubscribe from this group, send an email to: > > > ">http://docs.yahoo.com/info/terms/ > |
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Reply by ●March 15, 20032003-03-15
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I heartily agree with you. I have just come out of a fifteen year absence
from pcb making and was impressed by what is available. What I liked about the free Eagle download was that you are not limited by connections, just board size. One of the free/cheap ones that I surveyed went beyond its limit as soon as I loaded the 68HC11 from the library. Using this one (I can't remember which one, but IVEX comes to mind) you would have to edit your library parts for each design to remove those pins that you didn't need. The 68HC11 library for Eagle was complete as far as I wanted it - except for the annoying lack of a 34064 to get it started! However that was easy - I just took a three pin to92 and modified it. People have said that the software lacks a good library management editor - I didn't find that but maybe that's because I come from a command-line background. Those brought up on a WIMP interface may find it difficult. I have just stuffed the boards I made at APC - $200 CDN for 6 prototypes and I'll never go back to etching my own! Please re-consider your decision - especially if you have a mother/wife that doesn't like acid being spilled! I could have cut down my cost substantially ($50) by reducing the number of drills used - APC charges for those beyond the minimum. This may be because of the international nature of cadsoft.de and contributors to its library. That would be the only criticism I would have of Eagle. regards Nigel Johnson VE3ID/G4AJQ At 10:02 03-03-15 -0500, you wrote: >I am not familiar with the low-cost version of Eagle that you refer to, but >I use regular Eagle for my embedded design work and have a lot of respect >for it. > >Just as in trying to design with double sided boards, you will find that as >the component density goes up, the topological complexity of the design goes >up and you rapidly reach a point that your traces become "trapped" (i.e., >"you can't get there from here"). |
