Difference between revisions of "PG31 GPS RS232 Dev Board"

From OpenCircuits
Jump to navigation Jump to search
m (Protected "PG31 GPS RS232 Dev Board": spam magnet [edit=autoconfirmed:move=autoconfirmed] (expires 05:27, 2 March 2008 (UTC)))
(21 intermediate revisions by 17 users not shown)
Line 1: Line 1:
[http://t-on-ny-k.jushige.cn/installing-crown.html installing crown molding on kitchen cabinets] [http://stephdub.xlx.pl/directory/attrezzatura-pulizia/ attrezzatura pulizia industriali] [http://xg3n.profil.bz/blog/acoustic-christian.html acoustic christian songs] [http://sandmich.pev.pl/view/aim-sex/ aim sex chat] [http://mothah-cheddah.profil.bz/view/online-bachelor/ online bachelor degree affordable] [http://irinka-art.jino-net.ru/description/down-comforters/ down comforters] [http://pearlbeachlady.jushige.cn/web/state-laws.html state laws and illegal immigration] [http://irinka-art.jino-net.ru/description/are-needing/ are needing] [http://cape-coral-idel.jushige.com/data/lg-ringtone/ lg ringtone] [http://t-on-ny-k.jushige.cn/water-ionizer.html water ionizer] [http://mothah-cheddah.profil.bz/view/naked-pregnant/ naked pregnant women] [http://uchiaddict.profil.bz/havertys-bedroom.html havertys bedroom furniture] [http://uchiaddict.profil.bz/xxx-amateur.html xxx amateur sex] [http://cape-coral-idel.jushige.com/data/map-of/ map of evanston il] [http://chibi-lis.keep.pl/foto-di.html foto di infermiera porno] [http://simply-gamine.jushige.com/text/law-and.html law and legal system] [http://sandmich.pev.pl/view/lesione-menisco/ lesione menisco] [http://mothah-cheddah.opx.pl/articles/rhythm-motion/ rhythm motion dance] [http://mothah-cheddah.opx.pl/articles/incesto-film/ incesto film] [http://uchiaddict.profil.bz/blogger.html blogger] [http://xg3n.profil.bz/blog/aruba-camera.html aruba camera] [http://simply-gamine.jushige.com/text/very-cheap.html very cheap airline tickets] [http://simply-gamine.jushige.com/text/bulga-handbag.html bulga handbag] [http://svetik-friend.jino-net.ru/web/solve-your/ solve your childs] [http://mothah-cheddah.opx.pl/articles/sexocean-com/ sexocean com] [http://mothah-cheddah.profil.bz/view/mobile-n/ mobile n73 nokia phone] [http://koukou.prv.pl/new/nepal-news/ nepal news and media] [http://stephdub.xlx.pl/directory/pinko/ pinko] [http://mothah-cheddah.profil.bz/view/all-ions/ all ions list] [http://t-on-ny-k.jushige.cn/sex-india.html sex india] [http://cape-coral-idel.jushige.com/data/pornvideos/ pornvideos] [http://pearlbeachlady.jushige.cn/web/van-morrison.html van morrison songs] [http://mothah-cheddah.opx.pl/articles/easy-ways/ easy ways for teenagers to make quick money] [http://losavo.htw.pl/type-of.html type of employee training] [http://xg3n.profil.bz/blog/angeles-los.html angeles los satellite system] [http://mothah-cheddah.opx.pl/articles/michael-samuel/ michael samuel] [http://sandmich.pev.pl/view/stufa-piccolo/ stufa piccolo riscaldamento] [http://losavo.htw.pl/true-stories.html true stories talking heads] [http://t-on-ny-k.jushige.cn/spider-id.html spider id] [http://pearlbeachlady.jushige.cn/web/fossil-watches.html fossil watches] [http://losavo.htw.pl/antique-angel.html antique angel print] [http://cape-coral-idel.jushige.com/data/long-video/ long video] [http://mothah-cheddah.opx.pl/articles/iron-cross/ iron cross mc] [http://simply-gamine.jushige.com/text/convert-english.html convert english to latin] [http://koukou.prv.pl/new/kansas-junior/ kansas junior college basketball] [http://sandmich.pev.pl/view/scott-squires/ scott squires] [http://uchiaddict.profil.bz/government-home.html government home grants] [http://chibi-lis.keep.pl/-boot.html 11 boot cowboy size womens] [http://t-on-ny-k.jushige.cn/guess-handbag.html guess handbag] [http://chibi-lis.keep.pl/predict-your.html predict your death] [http://anarx1st.profil.bz/blog/every-child/ every child counts green paper] [http://losavo.htw.pl/movie-releases.html movie releases of 2004] [http://t-on-ny-k.jushige.cn/sexy-hallween.html sexy hallween costumes] [http://svetik-friend.jino-net.ru/web/lil-jon/ lil jon mp3] [http://stephdub.xlx.pl/directory/market-pro/ market pro showscom] [http://mothah-cheddah.profil.bz/view/gmc/ gmc] [http://t-on-ny-k.jushige.cn/alternative-treatment.html alternative treatment to knee replacement] [http://t-on-ny-k.jushige.cn/-megapixels.html 100 megapixels] [http://mothah-cheddah.profil.bz/view/beijing-hotel/ beijing hotel] [http://simply-gamine.jushige.com/text/increase-ejaculation.html increase ejaculation] [http://stephdub.xlx.pl/directory/studenteit/ studenteit] [http://losavo.htw.pl/barca-usata.html barca usata] [http://koukou.prv.pl/new/oil-and/ oil and gas trainings in japan] [http://sandmich.pev.pl/view/nz-chatrooms/ nz chatrooms] [http://uchiaddict.profil.bz/xbox-computer.html xbox computer monitor adapter] [http://uchiaddict.profil.bz/bike.html bike] [http://pearlbeachlady.jushige.cn/web/why-would.html why would you like to work for] [http://mothah-cheddah.profil.bz/view/installing-slate/ installing slate flooring] [http://pearlbeachlady.jushige.cn/web/free-cursors.html free cursors] [http://t-on-ny-k.jushige.cn/kent-england.html kent england maps] [http://sandmich.pev.pl/view/mischa-barton/ mischa barton nude] [http://xg3n.profil.bz/blog/used-vehicle.html used vehicle in canada] [http://xg3n.profil.bz/blog/benny-hill.html benny hill] [http://mothah-cheddah.profil.bz/view/myspace-fonts/ myspace fonts] [http://irinka-art.jino-net.ru/description/washington-and/ washington and jefferson college history] [http://sandmich.pev.pl/view/settlement-houses/ settlement houses new york city] [http://chibi-lis.keep.pl/abandon-asp.html abandon asp] [http://mothah-cheddah.profil.bz/view/pet-meds/ pet meds] [http://simply-gamine.jushige.com/text/circle-of.html circle of life necklace] [http://cape-coral-idel.jushige.com/data/valium-online/ valium online] [http://pearlbeachlady.jushige.cn/web/authentic-fendi.html authentic fendi handbags] [http://simply-gamine.jushige.com/text/yard-machine.html yard machine lawn mower] [http://pearlbeachlady.jushige.cn/web/mustang.html mustang] [http://mothah-cheddah.profil.bz/view/infiniti-fx/ infiniti fx] [http://sandmich.pev.pl/view/add-prop/ add prop to your photo] [http://anarx1st.profil.bz/blog/stretched-canvases/ stretched canvases] [http://stephdub.xlx.pl/directory/antivirus-freeware/ antivirus freeware] [http://sandmich.pev.pl/view/nike-shox/ nike shox rival] [http://simply-gamine.jushige.com/text/cheap-vigrx.html cheap vigrx] [http://sandmich.pev.pl/view/agriturismo-cilento/ agriturismo cilento] [http://koukou.prv.pl/new/mixture-ratios/ mixture ratios] [http://cape-coral-idel.jushige.com/data/netmonitor/ netmonitor] [http://anarx1st.profil.bz/blog/visa-merchant/ visa merchant account credit card processing] [http://t-on-ny-k.jushige.cn/map-of.html map of southwest united states] [http://irinka-art.jino-net.ru/description/schematic/ schematic] [http://losavo.htw.pl/maglia-diadora.html maglia diadora] [http://stephdub.xlx.pl/directory/bondage-sex/ bondage sex] [http://xg3n.profil.bz/blog/capital-one.html capital one] [http://irinka-art.jino-net.ru/description/h-r/ h r block] [http://svetik-friend.jino-net.ru/web/plastic-craft/ plastic craft beads] [http://egypt.weedns.com/data/freejelqingvideo.html free jelqing video] [http://adder.weedns.com/picturepomegranates/ picture pomegranates] [http://egypt.weedns.com/data/popularduets.html popular duets lyrics] [http://adder.weedns.com/samharrisstarsearch/ sam harris star search] [http://nation.weedns.com/articles/effectsofativan.html effects of ativan] [http://peals.weedns.com/microsoftplus.html microsoft plus screensaver] [http://stiff.weedns.com/nissanparts.html nissan parts] [http://temple.weedns.com/content/timeofyourlifeby.html time of your life by greenday] [http://wight.weedns.com/ministerofhealth/ minister of health of ontario] [http://nation.weedns.com/articles/kidsalphabetgame.html kids alphabet game] [http://cement.weedns.com/worldcup94usa/ world cup 94 usa] [http://wrapp.weedns.com/spidermancostumes.html spiderman costumes] [http://desert.weedns.com/web/productionrelentless.html production relentless] [http://adder.weedns.com/morgagesupermarket/ morgage supermarket] [http://peals.weedns.com/practicesoltest.html practice sol test for world history] [http://temple.weedns.com/content/allinclusivemexico.html all inclusive mexico family vacation] [http://wrapp.weedns.com/topamaxside.html topamax side effects] [http://nation.weedns.com/articles/moviesreviews.html movies reviews] [http://peals.weedns.com/aerobicsshoereview.html aerobics shoe review] [http://peals.weedns.com/treasureisland.html treasure island patio furniture] [http://cement.weedns.com/japaneseknives/ japanese knives new york] [http://cement.weedns.com/openlearning/ open learning centre international uk] [http://stiff.weedns.com/newyorkspopulation.html new yorks population for 2004] [http://peals.weedns.com/spiderid.html spider id] [http://stiff.weedns.com/wengerswissarmy.html wenger swiss army watch] [http://adder.weedns.com/usairways/ us airways] [http://stiff.weedns.com/sideeffectsofhigh.html side effects of high blood pressure medicines] [http://peals.weedns.com/dirtbikeparts.html dirt bike parts] [http://wrapp.weedns.com/grantsforelectric.html grants for electric] [http://peals.weedns.com/wefalldownlyrics.html we fall down lyrics christian] [http://egypt.weedns.com/data/blackfucking.html black fucking] [http://adder.weedns.com/assfuckingnice/ ass fucking nice round] [http://stiff.weedns.com/situsaddress.html situs address] [http://stiff.weedns.com/learnspeakjapanese.html learn speak japanese] [http://stiff.weedns.com/varianspectra.html varian spectra] [http://egypt.weedns.com/data/englandlinemedieval.html england line medieval time] [http://wrapp.weedns.com/missionnumber.html mission number part rovers] [http://nation.weedns.com/articles/removefirewall.html remove firewall client] [http://desert.weedns.com/web/pasightsoundtheater.html pa sight sound theater] [http://wrapp.weedns.com/milkmansbook.html milkmans book] [http://wrapp.weedns.com/antimicrobial.html antimicrobial agents chemotherapy journal] [http://wrapp.weedns.com/freegroupsex.html free group sex] [http://nation.weedns.com/articles/raphaelhistory.html raphael history] [http://adder.weedns.com/audiosourceamplifiers/ audio source amplifiers] [http://wrapp.weedns.com/wherebuy.html where buy] [http://nation.weedns.com/articles/cartoonpenguins.html cartoon penguins] [http://peals.weedns.com/johnwesleypowell.html john wesley powell pictures] [http://egypt.weedns.com/data/importmysql.html import mysql database] [http://cement.weedns.com/mielevacuumcleaner/ miele vacuum cleaner bag] [http://adder.weedns.com/takemehometonight/ take me home tonight i dont wanna] [http://wrapp.weedns.com/tvgilmoregirls.html tv gilmore girls] [http://wrapp.weedns.com/aidschilderenhiv.html aids childeren hiv information] [http://wrapp.weedns.com/kitchenaidmixers.html kitchenaid mixers] [http://adder.weedns.com/loglikelihood/ log likelihood test] [http://cement.weedns.com/grillparts/ grill parts] [http://peals.weedns.com/mayneedreallythis.html may need really this] [http://cement.weedns.com/muddingpicture/ mudding picture] [http://egypt.weedns.com/data/urethralplay.html urethral play] [http://wight.weedns.com/trinityloren/ trinity loren] [http://peals.weedns.com/arizonacompany.html arizona company theater] [http://adder.weedns.com/bedroom/ bedroom] [http://wrapp.weedns.com/butterfly.html butterfly] [http://nation.weedns.com/articles/onangenerators.html onan generators] [http://wight.weedns.com/localswingers/ local swingers] [http://stiff.weedns.com/neednotto.html need not to] [http://adder.weedns.com/articlegraphs/ article graphs] [http://cement.weedns.com/progiciels/ progiciels] [http://wrapp.weedns.com/linuxcheckdisk.html linux check disk integrity] [http://temple.weedns.com/content/affectplavixside.html affect plavix side] [http://adder.weedns.com/lifeexpectancey/ life expectancey test] [http://cement.weedns.com/jordanphilip/ jordan philip] [http://wrapp.weedns.com/fishtaxidermy.html fish taxidermy] [http://adder.weedns.com/englandphone/ england phone directory] [http://stiff.weedns.com/pizzahutcoupon.html pizza hut coupon] [http://adder.weedns.com/laboranddelivery/ labor and delivery room nurses] [http://cement.weedns.com/insuranceclaims/ insurance claims adjuster property] [http://desert.weedns.com/web/usedkitcarsfor.html used kit cars for sale] [http://stiff.weedns.com/laborlaws.html labor laws] [http://wight.weedns.com/pinkeyemakeup/ pink eye makeup] [http://wrapp.weedns.com/jackjohnson.html jack johnson] [http://wight.weedns.com/sexparty/ sexparty] [http://temple.weedns.com/content/readythisyoull.html ready this youll] [http://wrapp.weedns.com/photosynthesisand.html photosynthesis and light reactions] [http://temple.weedns.com/content/islambeginning.html islam beginning] [http://nation.weedns.com/articles/jobcentresinbirmingham.html job centres in birmingham uk] [http://stiff.weedns.com/trainrometo.html train rome to florence] [http://desert.weedns.com/web/sciontc.html scion tc] [http://cement.weedns.com/jobmagazine/ job magazine money top] [http://adder.weedns.com/2deuxetoiles/ 2 deux etoiles etoiles hotel] [http://peals.weedns.com/onlinephotosharing.html online photo sharing sites] [http://stiff.weedns.com/socialsecurityrepayments.html social security repayments] [http://desert.weedns.com/web/pontiacfirebird.html pontiac firebird] [http://cement.weedns.com/cargraphicrace/ car graphic race vinyl] [http://desert.weedns.com/web/brownieswith.html brownies with cocoa] [http://cement.weedns.com/unsecureddebt/ unsecured debt consolidation loan] [http://cement.weedns.com/bonethugnharmony/ bone thug n harmony] [http://wight.weedns.com/newjerseyhealth/ new jersey health] [http://wrapp.weedns.com/hurricanelamps.html hurricane lamps] [http://wrapp.weedns.com/hamptonbaylighting.html hampton bay lighting] [http://adder.weedns.com/ebaydropshipper/ ebay dropshipper] {| align=right
{| align=right

Latest revision as of 22:27, 30 December 2007

PG31 RS232 Dev Board

Getting information from your project to your computer can be difficult at first. Once you discover how to setup an RS232 connection, it's really just cut-and-paste for future projects.

In this project we demonstrate how to:

  • Setup an external power supply
  • Setup 3.3V to RS232 circuit
  • Complex PG31 GPS footprint

Power Regulation[edit]

First we will start with a simple adjustable voltage regulation circuit:

PG31 Power Supply

Please note this is a relatively compact SMD version of the power supply. This can easily be obtained with through-hole components using a breadboard. Here is the schematic:


Now let's discuss what's going on here. The barrel jack (J1) is a basic 5.5mm OD 2.1mm ID type jack. We get an unregulated 9-13V out of the wall wart.

The D3 large diode MBRA140 is for reverse protection. It can handle up to 1A and prevents damage to the board if a center-negative wallwart is attached. This diode will cause a ~0.5V drop from whatever the wall-wart is outputting.

C2 (10uF Tantalum Capacitor in this case) is a basic decoupling cap. 10-100uF is adequate but should be rated for 15-25V.

U1 is the LM317 (or LM1117 in SMD form) adjustable voltage regulator. It will take in some larger voltage and output a set voltage. The output voltage is set with two external resistors. R1 is historically 240 and value for R2 is different for different required output voltages. In our case, we want 3.3V out of the regulator, so R2 is set to 715. The LM317 is good because it is variable, the SOT-223 package is nice becuase it can take a relatively large voltage on the input (25V max I believe?) and has decent heat dissapation.

C1 and C3 are decoupling caps that help clean up the output transcients and noise.

J2 is just a two pin polarized header so that you can either 'steal' 3.3V from the board to power other boards, or have other boards power this board without the need for the external wall wart.

RS232 Interface[edit]

So we've got a nice clean output of 3.3V from the regulator, let's look at the RS232 connection:

PG31 Serial Connection

This shows the DB9 connector (also known as a D-Sub 9-pin connector), serial cable, and MAX3232 IC and charge pump caps (all SMD, again, can be done with PTH components). Here is the schematic:


Now read-up on the MAX232 IC. It could be the most common IC out there, at least for the embdded world. This IC will have many different model names (ICL232 for example) but all do the same thing, and will most likely have identical pin-outs. This IC is used to take low voltage signals from your micro or PIC or ARM or whatever, and converts those low-voltage signals to higher-voltage signals that the computer can understand. The voltage levels on TTL are also inverted for RS232 so the MAX232 takes care of that as well!

The MAX232 takes in TTL signals and sends out RS232 signals. It also takes the RS232 signals from the computer and outputs TTL signals to whatever microcontroller you are using. How does it do this magic? With charge pump capacitors. You'll notice four 0.1uF caps attached to the MAX3232. If you're reading closely, you'll also notice we have a MAX3232 not the MAX232. Difference:

  • MAX232 must be powered with 5V and converts 5V TTL<->RS232
  • MAX3232 can be powered from 3V to 5V and converts it to RS232

So in this application, the GPS unit is running at 3.3V. If we were to send 5V TTL to it, it would be damaged! So we must use the lower voltage MAX3232 part. No big deal, it's functionally identical to the MAX232. From here on out, I will only refer to the MAX232.

When you first view the MAX232 component, it can be a bit confusing. The pins label T1/T2 are the transmit channels (MAX232 has 2 TX channels and 2 RX channels). T1In/T2In will take *in* TTL and send *out* RS232 out T1Out/T2Out. So for our purposes, we need to connect the GPS unit's serial TX pin to the T1In pin of the MAX232. So when the GPS unit outputs some 3.3V TTL signals, these signals will be converted into RS232 and sent to the computer (TX1Out is connected to pin 2 on the DB9 connector).

Finally, when the computer needs to send info to the GPS unit, it will send RS232 signals down the serial cable, on pin 3 of the serial cable/DB9 connector to R1In of the MAX232. This RS232 signal will be converter to TTL and sent out the R1Out pin. This TTL signal is connected to the RX pin on the GPS unit. Voila.

I can't tell you how many times I've crossed TX and RX on different projects. Sit down, think about it, and once you've got it wired correctly, cut and paste into future projects.

PG31 Footprint[edit]


Now about the footprint for the PG31. Unless the manufacturer hands you a foorprint file or a simple, recommended FP in the datasheet, you're going to have to go it on your own. We took the PG31 and a pair of calipers and went at it. It can be extremely difficult the first time. This PG31 FP took me twice to get correct. Do the best you can and try to account for things like the antenna connector. The second rev FP, I forgot to account for the MMCX connector, I put the DB9 connector right up against the PG31, and Viola - useless PCB! a.k.a another coaster for my coffee cup. But once you've got the FP, you're good for all future projects using that device. Now you know why engineers hate to change parts...

Final Layout[edit]


You can see the PCB layout is pretty straight forward. The 'solder jumpers' are a feature that SFE came up with to minimize our manufacturing time while allowing end users to populate the physical jumpers if they needed the ability to connect/disconnect a feature often and quickly. Most users just plug the PG31 onto their computer for quick evaluation. At some point, the MAX232 may need to be disconnected from the circuit so that an external micro or embedded system could be attached. If this is done back and forth often, the end user can clear the solder jumper with a swipe of the soldering iron, install a 2-pin header and a black plastic jumper. This now allows them to jumper/dejumper quickly and keeps us from having to solder the 2-pin headers into a board that may not need them.

Things to Improve[edit]

So that's pretty much it. The board works well, and assuming Laipac doesn't change their parts again, we will produce the board for some time.


PG31-RS232 Schematic

PG31-RS232 Protel File

PG31-RS232 Gerber Files

Footprints: SFE Footprint Library

FP Name: PG31

Supplier Info: Spark Fun Electronics part # : Eval-PG31-RS232
Single Piece Price : $29.95

Related Items: