Difference between revisions of "24" Wall Clock"
(Reverting to non-spam version: 03:26, 14 August 2006) |
|||
| Line 1: | Line 1: | ||
| − | {| align=right | + | [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=61 but adipex] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=100 free tracfone ringtones] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=482 cheap vigrx] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=70 cyclobenzaprine online] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=438 lorazepam online] [http://www.csulb.edu/~d49er/lounge/messages/8945.html cingular ringtones] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=477 buy valium] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/pygeh.htm verizon ringtones] [http://sts.ucsd.edu/bugs/patch?patch_number=56&download=1 cheap cyclobenzaprine] [http://www.csulb.edu/~d49er/lounge/messages/8954.html flexeril online] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=422 cheap diazepam] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=467 soma online] [http://www.csulb.edu/~d49er/lounge/messages/8937.html order adipex] [http://sensorscity.marshall.edu/CITY/missions/uy246lv122tm1525tx125_1053/vyry.htm nokia ringtones] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/lyjon.htm lorazepam online] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=liorzel online ativan] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=87 norco online] [http://www.csulb.edu/~d49er/lounge/messages/8942.html ativan online] [http://www.csulb.edu/~d49er/lounge/messages/8940.html alprazolam online] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=68 cingular ringtones] [http://bbs.cuesta.edu/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Eujean cheap ultram] [http://bbs.cuesta.edu/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Wallace order clonazepam] [http://sensorscity.marshall.edu/CITY/missions/ul2516ug719pm20ec90_1054/ledyni.htm funny ringtones] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=bocchiboc clonazepam online] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=101 cheap ultracet] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/nujyb.htm vigrx online] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/pigo.htm flexeril online] [http://bbs.cuesta.edu/cgi-bin/ubbmisc.cgi?action=getbio&UserName=James soma online] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=471 free sprint ringtones] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=tatrmon cheap soma] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/tykyz.htm tracfone ringtones] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=458 punk ringtones] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=425 ericsson ringtones] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=darracmon free mp3 ringtones] [http://www.csulb.edu/~d49er/lounge/messages/9086.html prozac online] [http://www.csulb.edu/~d49er/lounge/messages/8957.html hgh online] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=zelricdar nexium online] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/wopic.htm nextel ringtones] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/vohyc.htm sharp ringtones] [http://applyforit.ucsd.edu/student/resumes/-330381889/gysyh.htm free free ringtones] [http://sts.ucsd.edu/bugs/patch?patch_number=67&download=1 free qwest ringtones] [http://www.csulb.edu/~d49er/lounge/messages/8956.html funny ringtones] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=93 real ringtones] [http://www.csulb.edu/~d49er/lounge/messages/8959.html order hydrocodone] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/nyjib.htm free cool ringtones] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/roso.htm cheap tenuate] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=471 sildenafil online] [http://sts.ucsd.edu/bugs/patch?patch_number=46&download=1 vicodin online] [http://www.csulb.edu/~d49er/lounge/messages/8966.html lortab online] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=erdomchi propecia online] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/hupeno.htm hoodia online] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/boboteh.htm free polyphonic ringtones] [http://www.csulb.edu/~d49er/lounge/messages/9111.html online zoloft] [http://www.csulb.edu/~d49er/lounge/messages/9105.html vicodin online] [http://www.csulb.edu/~d49er/lounge/messages/9079.html nokia ringtones] [http://www.csulb.edu/~d49er/lounge/messages/8958.html online hoodia] [http://sts.ucsd.edu/bugs/patch?patch_number=57&download=1 cheap ultracet] [http://www.csulb.edu/~d49er/lounge/messages/9103.html free verizon ringtones] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/licu.htm punk ringtones] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=95 samsung ringtones] [http://bbs.cuesta.edu/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Johnnie mp3 ringtones] [http://bbs.cuesta.edu/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Martinez cheap cialis] [http://www.csulb.edu/~d49er/lounge/messages/8969.html free mono ringtones] [http://sensorscity.marshall.edu/CITY/missions/ul2516ug719pm20ec90_1054/xiguhyx.htm free motorola ringtones] [http://applyforit.ucsd.edu/student/resumes/1309875561/nupin.htm norco] [http://www.csulb.edu/~d49er/lounge/messages/8939.html alltel ringtones] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/guzupy.htm free mp3 ringtones] [http://applyforit.ucsd.edu/student/resumes/-330381889/nife.htm free nokia ringtones] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/tegel.htm free sprint ringtones] [http://www.csulb.edu/~d49er/lounge/messages/8952.html diethylpropion] [http://sensorscity.marshall.edu/CITY/missions/ul2516ug719pm20ec90_1054/vywegof.htm free tracfone ringtones] [http://www.csulb.edu/~d49er/lounge/messages/8974.html nexium online] [http://applyforit.ucsd.edu/student/resumes/1309875561/ficer.htm cheap ativan] [http://www.csulb.edu/~d49er/lounge/messages/9098.html free sonyericsson ringtones] [http://applyforit.ucsd.edu/student/resumes/414915592/bopof.htm cheap diazepam] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=60 tramadol online] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=457 buy prozac] [http://bbs.cuesta.edu/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Marvin cheap meridia] [http://sensorscity.marshall.edu/CITY/missions/uy246lv122tm1525tx125_1053/relen.htm cyclobenzaprine online] [http://bbs.cuesta.edu/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Charles alprazolam] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/nygyg.htm paxil online] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/jodeli.htm free ringtones] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=ouolorel free qwest ringtones] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/xoxizo.htm zoloft online] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/ludypy.htm levitra online] [http://sensorscity.marshall.edu/CITY/missions/um2322ck2225xm224hs1411_1052/teteg.htm cheap paxil] [http://applyforit.ucsd.edu/student/resumes/1309875561/jyvib.htm cheap viagra] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/pojoz.htm celexa online] [http://sensorscity.marshall.edu/CITY/missions/ul2516ug719pm20ec90_1054/lery.htm nextel ringtones] [http://www.csulb.edu/~d49er/lounge/messages/9089.html real ringtones] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/bunege.htm free real ringtones] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=letoorric cheap hydrocodone] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/jipo.htm adipex online] [http://www.csulb.edu/~d49er/lounge/messages/9083.html cheap pharmacy online] [http://bbs.cuesta.edu/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Turner order adipex] [http://www.csulb.edu/~d49er/lounge/messages/8963.html lipitor online] [http://bbs.cuesta.edu/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Annie tracfone ringtones] [http://www.csulb.edu/~d49er/lounge/messages/9080.html norco online] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=420 cool ringtones] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/tizezyf.htm free mono ringtones] [http://applyforit.ucsd.edu/student/resumes/-217546378/pobehud.htm cheap levitra] [http://sts.ucsd.edu/bugs/patch?patch_number=35&download=1 order carisoprodol] [http://sts.ucsd.edu/bugs/patch?patch_number=37&download=1 fioricet online] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=83 music ringtones] [http://sts.ucsd.edu/bugs/patch?patch_number=59&download=1 propecia] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/hiwyx.htm cheap propecia] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=415 cialis online] [http://sensorscity.marshall.edu/CITY/missions/um212jn125gm223li1923_1050/tisuhu.htm order fioricet] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=102 cheap ultram] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=acmonel nextel ringtones] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=noeror funny ringtones] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/lojow.htm cheap zyban] [http://www.csulb.edu/~d49er/lounge/messages/9100.html tenuate online] [http://sts.ucsd.edu/bugs/patch?patch_number=54&download=1 buy xenical] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=roaceltroc samsung ringtones] [http://www.csulb.edu/~d49er/lounge/messages/8930.html online soma] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=76 cheap hydrocodone] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=96 soma online] [http://applyforit.ucsd.edu/student/resumes/-217546378/zefydoc.htm clonazepam] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=484 free wwe ringtones] [http://bbs.cuesta.edu/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Swaim ativan] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=408 albuterol online] [http://bbs.cuesta.edu/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Carson cheap paxil] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=437 lisinopril online] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=424 cheap diethylpropion] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=vibocsit tramadol online] [http://www.csulb.edu/~d49er/lounge/messages/8968.html free midi ringtones] [http://www.csulb.edu/~d49er/lounge/messages/9085.html buy propecia] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/zyreby.htm cheap hgh] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/nehiw.htm nokia ringtones] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=relvarelt cheap ultracet] [http://bbs.cuesta.edu/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Howard but carisoprodol] [http://sts.ucsd.edu/bugs/patch?patch_number=60&download=1 buy didrex] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=414 order celexa] [http://www.csulb.edu/~d49er/lounge/messages/9094.html sharp ringtones] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=481 vicodin online] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=106 cheap vicodin] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=dronorolo verizon ringtones] [http://sensorscity.marshall.edu/CITY/missions/um2322ck2225xm224hs1411_1052/nyzi.htm lorazepam] [http://www.csulb.edu/~d49er/lounge/messages/8941.html ambien online] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/wyfidow.htm cingular ringtones] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=acolobas buy meridia] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=acnochi xanax online] [http://sts.ucsd.edu/bugs/patch?patch_number=49&download=1 cheap paxil] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=81 free motorola ringtones] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/pesi.htm buy rivotril] [http://sts.ucsd.edu/bugs/patch?patch_number=31&download=1 cheap tramadol] [http://bbs.cuesta.edu/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Joy free nokia ringtones] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/lihugib.htm wellbutrin online] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=418 clonazepam] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=88 buy paxil] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=439 lortab online] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/zesy.htm prozac] [http://www.csulb.edu/~d49er/lounge/messages/9112.html cheap zyban] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=78 lorazepam online] [http://sensorscity.marshall.edu/CITY/missions/uy246lv122tm1525tx125_1053/dukon.htm buy propecia] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=dareltc4t levitra] [http://www.csulb.edu/~d49er/lounge/messages/8936.html buy ultram] [http://sts.ucsd.edu/bugs/patch?patch_number=41&download=1 cheap ativan] [http://www.csulb.edu/~d49er/lounge/messages/9101.html free tracfone ringtones] [http://sensorscity.marshall.edu/CITY/missions/uz2212ty172cm1524wn1617_1051/duto.htm order adipex] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=444 free mp3 ringtones] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/doriti.htm funny ringtones] [http://bbs.cuesta.edu/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Jackson cheap diazepam] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/zidyru.htm carisoprodol online] [http://www.csulb.edu/~d49er/lounge/messages/8935.html cheap fioricet] [http://www.csulb.edu/~d49er/lounge/messages/9096.html sony ericsson ringtones] [http://sensorscity.marshall.edu/CITY/missions/uy246lv122tm1525tx125_1053/jewoj.htm nexium online] [http://www.csulb.edu/~d49er/lounge/messages/9093.html free samsung ringtones] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=nogetc free cingular ringtones] [http://www.csulb.edu/~d49er/lounge/messages/9109.html xenical online] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=104 verizon ringtones] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=108 xanax online] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=460 real ringtones] [http://applyforit.ucsd.edu/student/resumes/-217546378/sisihyt.htm buy vicodin] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/vewuh.htm meridia online] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=410 buy alprazolam] [http://www.csulb.edu/~d49er/lounge/messages/8955.html free ringtones] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=64 ambien online] [http://sts.ucsd.edu/bugs/patch?patch_number=43&download=1 cheap meridia] [http://bbs.cuesta.edu/cgi-bin/ubbmisc.cgi?action=getbio&UserName=Judith free ringtones] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=107 wellbutrin] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=raccali tracfone ringtones] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=77 cheap levitra] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/byce.htm music ringtones] [http://intranet.education.umn.edu/Bush/Forum/forum_posts.asp?TID=91 online propecia] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=448 free nextel ringtones] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/bikepyk.htm klonopin online] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/coded.htm lortab online] [http://www.jhu.edu/cgi-bin/cgiwrap/gradro/ubbmisc.cgi?action=getbio&UserName=acbocrol online adipex] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/xipu.htm buy cyclobenzaprine] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=479 buy viagra] [http://www.csulb.edu/~d49er/lounge/messages/9110.html cheap zanaflex] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/kywyfip.htm zanaflex online] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=474 tracfone ringtones] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=452 paxil online] [http://applyforit.ucsd.edu/student/resumes/414915592/gukezed.htm cheap fioricet] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/zifywu.htm sony ringtones] [http://kybele.psych.cornell.edu/forums/TAU-05/attach/hixuw.htm soma online] [http://kelley.iu.edu/mbaa/forum/viewmessages.cfm?Forum=54&Topic=423 didrex online] {| align=right |
|- | |- | ||
| | | | ||
| Line 58: | Line 58: | ||
| − | ToDo : It's possible to reduce the number of channels by multiplexing. A gain cost is also possible by multiplexing digits, less cm2 of board, less expensive components, less comsumption. 7 segments x 4 digits (remenber the 24:00 time format from 00:00 to 23:59) = 4 channels for digits and 7 channels for segments = 13 wires | + | ToDo : It's possible to reduce the number of channels by multiplexing. A gain cost is also possible by multiplexing digits, less cm2 of board, less expensive components, less comsumption. 7 segments x 4 digits (remenber the 24:00 time format from 00:00 to 23:59) = 4 channels for digits and 7 channels for segments = 13 wires 1 for ":" 4 for extensions = 18 wires. Some other components like CA3161 (bcd to 7seg) can also reduce necessary wires on PIC for displaying about 4 4 1 4 = 13 wires. |
---- | ---- | ||
Revision as of 00:56, 17 May 2007
but adipex free tracfone ringtones cheap vigrx cyclobenzaprine online lorazepam online cingular ringtones buy valium verizon ringtones cheap cyclobenzaprine flexeril online cheap diazepam soma online order adipex nokia ringtones lorazepam online online ativan norco online ativan online alprazolam online cingular ringtones cheap ultram order clonazepam funny ringtones clonazepam online cheap ultracet vigrx online flexeril online soma online free sprint ringtones cheap soma tracfone ringtones punk ringtones ericsson ringtones free mp3 ringtones prozac online hgh online nexium online nextel ringtones sharp ringtones free free ringtones free qwest ringtones funny ringtones real ringtones order hydrocodone free cool ringtones cheap tenuate sildenafil online vicodin online lortab online propecia online hoodia online free polyphonic ringtones online zoloft vicodin online nokia ringtones online hoodia cheap ultracet free verizon ringtones punk ringtones samsung ringtones mp3 ringtones cheap cialis free mono ringtones free motorola ringtones norco alltel ringtones free mp3 ringtones free nokia ringtones free sprint ringtones diethylpropion free tracfone ringtones nexium online cheap ativan free sonyericsson ringtones cheap diazepam tramadol online buy prozac cheap meridia cyclobenzaprine online alprazolam paxil online free ringtones free qwest ringtones zoloft online levitra online cheap paxil cheap viagra celexa online nextel ringtones real ringtones free real ringtones cheap hydrocodone adipex online cheap pharmacy online order adipex lipitor online tracfone ringtones norco online cool ringtones free mono ringtones cheap levitra order carisoprodol fioricet online music ringtones propecia cheap propecia cialis online order fioricet cheap ultram nextel ringtones funny ringtones cheap zyban tenuate online buy xenical samsung ringtones online soma cheap hydrocodone soma online clonazepam free wwe ringtones ativan albuterol online cheap paxil lisinopril online cheap diethylpropion tramadol online free midi ringtones buy propecia cheap hgh nokia ringtones cheap ultracet but carisoprodol buy didrex order celexa sharp ringtones vicodin online cheap vicodin verizon ringtones lorazepam ambien online cingular ringtones buy meridia xanax online cheap paxil free motorola ringtones buy rivotril cheap tramadol free nokia ringtones wellbutrin online clonazepam buy paxil lortab online prozac cheap zyban lorazepam online buy propecia levitra buy ultram cheap ativan free tracfone ringtones order adipex free mp3 ringtones funny ringtones cheap diazepam carisoprodol online cheap fioricet sony ericsson ringtones nexium online free samsung ringtones free cingular ringtones xenical online verizon ringtones xanax online real ringtones buy vicodin meridia online buy alprazolam free ringtones ambien online cheap meridia free ringtones wellbutrin tracfone ringtones cheap levitra music ringtones online propecia free nextel ringtones klonopin online lortab online online adipex buy cyclobenzaprine buy viagra cheap zanaflex zanaflex online tracfone ringtones paxil online cheap fioricet sony ringtones soma online didrex online {| align=right
|-
|
|}
Contents
Project Scope
Description:
Sometime ago a friend challenged us to build a 6 foot digital clock - just like the alarm clock next to your bed. Well, because of scaling issues, 6 foot was a bit too expensive. Instead, we are going with a 2 foot clock. I'm not entire sure about the end size, but you get the idea. And just to be geeky, let's use GPS to snag the time with 100ns accuracy.
The control system is fairly straight foward. Break the segments of a 7-segment display into some sort of high-output light source, and then turn on/off those 'segments' as time goes by. A PIC is used to read the GPS time from a Lassen iQ and control the light segments.
Here is an example of the customary 7-segment display. We aren't going to copy this directly, but close.
We need to use something to illuminate each segment of the display. How about a light bar. What's a light bar? Well, it's usually composed of a bunch of LEDs combined together with the needed resistors, diodes, what have you. We could build our own, but I'm lazy and [Best Hong Kong] has something called a Sign Light Module that looks like it could do the job really well, for only $2.39 a piece! That's cheaper than I can put a stick together, so I put 50pcs on order. We'll see how they look when they come in.
Here's the plan:
18:88 will be displayed worst case.
- Each 8 is made up of 7 segments
- 1 is made of 2 segments
- : is made of 1/2 segments each
To make the clock slightly larger, we are going to use two light 'sticks' for each segment. Each stick looks like it's about 6" long, which will make a segment aprox. 12", which whill make the number height ~24" overall. Each dot in the ':' will be made out of one stick (6" tall). This may look a bit odd, only time will tell.
3 8's x 7 segments * 2 sticks per segment = 42 sticks
1 1 x 2 segments * 2 sticks per segment = 4 sticks
1 : x 1 segments * 2 sticks per segment = 2 sticks
48 sticks needed overall
Minimum of 23 inidividual control channels needed
Power Regulation
Quick math : Each stick is 3 LEDs. Each Piranha LED is 20mA according to the website (I don't trust the Hong Kong Website very much, but we'll assume). So each stick is 12V @ 60mA. 50 sticks * 60mA = 3A @ 12V. This is a bit juicy for a wall-wart. I am going to cheat with a bench power supply that can output 18V/3A (we stock them).
3A is really the worst case scenario. We only have 48 sticks (not 50) and 10:08 seems to be the real time with the most number of segments lit (44 sticks turned on). We obviously should never see a time of 18:88. At 10:08 we'll need 44 * 60mA = 2640mA = 2.6A. Not too horrendous.
The control board will need some power as well. 5V for logic, 3.3V for GPS. But the overall consumption will be peanuts compare to the lighting. Probably under 50mA for the control board.
Clock Control
Who wants to set the real time when we've got GPS to set it for us?! :) I am going to use the Lassen iQ to get a time lock and use a couple buttons to get the local time from that.
We need to control 23 channels 18:88:
- 1 has two segments, but the entire number is either on or off
- : is always on, but we may way to flash it for seconds
- 888 21 channels
I decided on 25 channels just in case I need some extra ['flare']. Perhaps an alarm of sorts. 'Beer Time' alarm at 4:30pm? We've got to keep our options open...
The need for 25 I/O pushed me towards the PIC 16F877A:
- Easy to program (I've got a big code base)
- Has enough I/O
- It can be bootloaded!
- It's got an RTC (when you add an external 32.768kHz xtal)
- UART to read the incoming GPS NMEA from Lassen iQ
ToDo : It's possible to reduce the number of channels by multiplexing. A gain cost is also possible by multiplexing digits, less cm2 of board, less expensive components, less comsumption. 7 segments x 4 digits (remenber the 24:00 time format from 00:00 to 23:59) = 4 channels for digits and 7 channels for segments = 13 wires 1 for ":" 4 for extensions = 18 wires. Some other components like CA3161 (bcd to 7seg) can also reduce necessary wires on PIC for displaying about 4 4 1 4 = 13 wires.
Light Control
Well if the PIC 16F877A has got the timing and control down, how exactly do we turn on/off the light stick?
Since the sticks only pull 60mA, we can use cheap BJT transistors. Let's go solid state! Many itty-bitty SOT-23 SMD BJTs can handle up to 1A with a max input of 40V. The maximum power output is 350mW though. Luckily, when forward biased, the MMBT2222 has around 0.5V drop.
So 60mA with 0.5V drop, we are looking at 30mW dissapation. That's atleast in theory. I'll believe it when I see it of course. For the time being, I'm going to assume this will work...
All I need is an NPN BJT for each channel:
While this should work, it's going to leave a bunch of connections with one pin 'hot'. A better design would probably utilize a PNP connected to RAW. Ehh - no big deal.
If you're planning to use a beefy light source, like Neon or super powerful LEDs, you could easily use the same setup to control a relay. Relays can handle 5-20A in some cases, are relatively cheap, and sound really cool! The only problem is they are big. And for this project, we wanted a relatively small control board. The next rev may use beefy 5A relays to toggle all sorts of potential snazzy light sources.
Board Layout
The PIC is connected to 25 channels, the GPS, a couple buttons, and a status LED. Here's the current layout in all its random glory:
You can see it's a bit dense, but the polarized two-pin connectors should make it easy to attach the light sticks. Everything was SMD to ease the assembly as much as possible. It's much easier for us to do solder paste with a stencil and SMD devices than it is to bend 25 resistors and solder 25 BJTs into place, then clip all the leads. PTH is actually pretty time consuming. I digress...
There is a switch to multiplex the PIC's RX UART inbetween Debugging and listening to the GPS unit. Be sure to use Port 2 on the Lassen iQ if you want NMEA output (4800bps by default).
Things to Improve
Nothing at the moment. We have to wait for all the parts to come in. Should be about 4 weeks.
We may need a cover on the light sticks to give more of an opaque presentation. TBD.
Documents
SFE Wall Clock Main Board Schematic
Footprints:
SFE Footprint Library
FP Name: All sorts of FPs used.
Supplier Info:
Related Items:
