PG31 GPS USB Dev Board

From OpenCircuits
Revision as of 20:08, 8 October 2007 by 64.122.174.218 (Talk)

Jump to: navigation, search

Brasile ristorante Ermafroditi foto Astrologia linea Sistema qualita Xena porno Meteo alpi svizzera Ricetta con cioccolato Sex dragon ball Peso perdita herbalife distributore Gilet omologati Grand hotel cesenatico Porno lesbiche Pannello solare Robin hood Volvo usato Pompini amatoriali Faretti alogeni Balbuzie Voyeur italia Porno pussy Hotel dobbiaco Foto amatoriali coppie Anna ohura Offerta flat adsl Tartaruga maori Settimanali Cumshot teens cartoni sexi Pamela prati senza mutande Yahoo gruppo Mature lesbian Foto amatoriali culi Ricetta pasta sarda Dvd vergini gb Cancun hotel Dispnea mononucleosi Albergo timisoara Galapagos vacanza Gestionale per agenzia viaggi Yatch Nere nude Melita diavolita nuda Basketball betting college line Vacanza agriturismo toscana Finanziamento ascoli Musica classica radio Goku porno Impdap Cassa forense avvocato Diavolita calendario Driver stampante hp 930c Casino slots online Significato natica Skyeurope volo low cost europa centrale Pallanuoto Foto incesto padre figlia Milano assicurazione Bluvacanze Krystal steal yacht fuck Bad credit refinance Sborrate in bocca Ciunga it Quotazione auto usata Download morpheus Flora enchantix Regency hotel Bandabardo Confronto assicurazione Non recidere forbice quel volto parafrasi porno film gratis anteprime Vecchie grasse porche Inarcassa Hairy woman Incontri gay Ricetta antipasto particolare Massaggi cinesi a milano Albergo due stella stoccolma Visura Archivio superenalotto Rivista italiane Jeans diesel zathan Sexy immagini Mozzilla Troie giovani Disegni bambini Copertina cd daniele silvestri Suoneria panasonic gd87 Albergo pisa Donnafugata Cartina toscana Scopate nonne nipoti Trova lavoro all estero Foto amatoriali moglie nuda Prestito calabria online Trans pompini Stampante hp photosmart Missoni roberta Barbaresco dei produttore Ragazze lesbica Porno giapponesi Fighe dilatate Mercatino usato caravan Vecchie troie puttane Modello lettera dimissioni Zaino trolley Aspirapolvere dyson Amateur facials Claudia antonelli porno temi nokia jar Campeggio veliero Video gratis roberta missoni Sex gratis Payday cash loan Antivirus gratis Codici pokemon smeraldo gba Box astalavista sk Ricetta vegetariane Camera barcellona Frasi d anniversario Rapolano terme Ascoltare musica Istruzionelazioit Raffaella berge Psoriasi marocco Foto porno incesto Www winxclub it Ventilatore a piantana Figa tanto pelosa Selena spice fuck Nadia bengala Artigiani caminetto Hw upgrade dissipatore Veranda terrazzi Leucociti wbc Finanziamento udine Csa bologna Salsa formaggio Roms n64 Marilyn manson Alena seredova video Autonoleggio torino Lino banfi Anal fist Creare loghi Bear share com Meteoriti Foto di adolescenti Portaportese alessandro Gazzetta ufficiale it I grandi viaggi Sesso incontro cosenza Sesso in collant Spyware doctor troubleshooting Corpetto sportivo Contatti msn porno Siena cose fare Spyware adware remover Miti e leggenda Anteprima sex Ormoni Sara tommasi Www italiachiamami net Pamela neri Cumshot teens Villa in tuscany Finanziamento parma Satriani joe Adele stephens stevens Hotel palau ita Foto rubata Tiscali lavoro Elenco pornostars Sinergy five Ex geoweb Ascoli piceno Bed and breakfast ostuni Playstation 2 trucchi Zed it Magazzino as roma ultra Rivestimenti in pietra naturale Carnival cruise line Troie incinte Rosita celentano porno Mature big tit Video sesso Flower delivery Universita di verona Negre calde Mutuionline it Volo flyairone Tgcom gossip Spyware eliminator Test sullamore Messagero veneto Apartment austin Bahama ristorante Selen porno star Simone inzaghi Motore per barche usati Stoccolma scandic hotel sergel plaza jennifer lopez live ati radeon x600xt 128mb athlon64 4800 ursula cavalcante diario di un parroco di campagna wholesale jewelry perversione sessuale con animali sally di vasco rossi universita federico ii napoli scopa elettrica amstrad headbangers ball www togni it mica milano calze ever dream videos de reggaetony cavo alpine iq maraton deviant monitor acer al 1912 il bacio di una morta toshiba 145 logitech pocket como comunicazione mara piromalli hotel bratislava webcam e chat sempre aperte senza dailer mercedes clk cabriolet lavastoviglie da incasso integrata racconti und sculacciate st microeletronics frankie goes to hollywood vacanze a portofino giochi per mac il cane infernale video seconda guerra mondiale motori di ricerca mondiali si deamain world driver championship cavo usb qtek 2020 www pagine gialle it sem flipside divlje jagode marija cuccarini nuda sveglia da parete ladc52c canon la road wars salvo dacquisto tv color amstrad 14 combi beautiful soapopera kazaa download ferdinando cecchini idaho cose fare delfini macchina popcorn carta adesiva executione suonerie siciliane ivan i delfin czarne oczy www calcio mercato palermo it die sekte masterizzatore esterno masterizzatori cd grand valley swan t shirt design donki esporto brasil fiat punto sx tracce esame maturita 2004 videoa amatoriali tu semplicita maria anrea delogu fiat punto van km 0 liricos de reggaeton top class escort software nokia 6210 golf e country club kyashan dvd cover ascolta www goolge la demo va allo zoo radici tieni andrea di stefano sony mdr v700 dragon bol mix anni 60 wwe raw music calendario letterine manga love sexy anna dancin with an angel be breakfast scopello valsesia immagini della donna nell 800 cicladi ulisse joyce trama athlon 4200 video del decapitado tps matrix the house off the rising sun us air force usbstor sys pharaohs curse gold 150 selajdin miftari assicurazione pomezia adam arkin lifeview flydvbt il cielo in una stanza testo foto di armi antiche km0 volvo s60 d5 diesel il monte sieben notturni chopin www pappa pino daniele pigro ruota navigatore altimetro diegotorres sex and animal ati radeon x700pro 256mb miami (etnologia) e percio ci si offre campo di conoscere savex srl ragazze di bolzano larne itinerario lazio indirizzo inter club orange walk canon rs60 e3 coolpix 4200 accessori flash pantaloni da uomo dvdrw cd e dvd vergini darter king madona testo leali netsim v5 27 router hercules roma campo flaminio lascia l ultimo ballo per me deep paint 2 1 1 4 digitale samsung agriturismo grugliasco www porno com uy maserati spyder rachid system strauss und torney lulu von km0 mercedes ml auto km 0 das bo v980 cavo dati spedizioni internazionali black blowjob upskirt tv ragazzo san donato milanese exitos latinos frigoriferi in acciaio castelli campania ristoranti netgear access point router wireless intel centrino cristina milian dip it low pronostico coppa uefa fly drugs sanaga maritime imetec iron max compact 2600 istituto cervantes di roma annalisa caputo coolermaster aquagate www aerosmith it mest batteria al litio per fotocamere canon la puntura nokia umts 6680 juan gabriel abrazame muy fuerte mc conrad radio deejay it saint pier mamma di roy il signore degli anelli la trilogia mejores traseros claudia shiffer graceland finale aeron feste in provincia di modena la vita no e un film stampante all in one radio fm usb pc racchette da tennis salp l iliade imate sp5m do g s get to go to heaven giochi mc donald phedra lancia van cliburn concert pianist kill bill theme sankt lorenzen livecam marx it asrock p4v88 atx sata golf auto creator {| align=right |- | PG31 USB Dev Board |} Description:
You've probably heard about the CP210x USB ICs from Silicon Labs, now here's an application that uses it. The CP2102 gives us 3V TTL to a VCP (virtual comm port) over USB as well as generating the 3.3V needed for the board.

In this project we demonstrate how to:

  • Setup a USB to Serial link
  • Use the CP2102 for 3.3V
  • Use a SMD 12mm battery holder

Contents

USB Connection

The CP2102 USB IC is fairly easy to use once you've plugged it down a couple times.

PG31 USB Connection

The USB connector has four pins : Vcc (*around* 5V), GND, D , D-. Tying these four connections to the CP2102 is easy enough.

PG31-USB-Connection-Schematic.jpg

There are a couple things to note. In this setup, we do not have any ESD protection or surge supression. We are quite possibly violating some USB standards. But does it work? Yep.

When you configure the CP2102 this way, it can source up to 100mA at 3.3V using its internal voltage regulator. This is perfect for our application as the PG31 needs ~40mA at 3.3V.

Note the TX pin on the CP2102 is an output and needs to be connected to the RX pin on the PG31. This screwed me up a few times.

The CP2102 has built-in cystal and eeprom. These means you need very few external components to get it working. You can even program in your own ID string so when you plug it onto your computer, it comes up with the name of your widget!

When the CP210x is attached to a computer (and it's soldered correctly) you will see windows hardware wizard request drivers. These drivers can be downloaded from SI Labs. You can also create your own signature drivers using some SI Labs software.

You can also program the internal EEPROM to reflect your own product ID and serial strings. This software is from SI Labs as well but I forget were - when someone finds it, post it here.

Once the drivers are installed, the CP210x will turn into a serial com port! Yes! It's weird to think about until you see it happen. So this USB dev board now acts like a com port on my computer. All I have to do is pass characters in and out COM 5 (for example) and I can do things over USB! No messy drivers, no protocols to think about, it's all done in the IC. All right!

One thing to note when you are using the CP210x ICs, the Linux community may scoff. SI Labs did a great job with the windows support, but a piss-poor job of opening the drivers for the open-source community. I'm not really a Linux person so it didn't effect me. But if your app needs linux connectivity, you may want to take a quick look for other potential ICs. Last I heard, there was good Linux support for the CP2102, but there was nothing for the CP2103 GPIO control...

One last con : The ICs come in QFN leadless package only. YES it can be soldered by hand, but you'll need some experience and/or some good hot-air soldering tools. I taught myself how to rework stuff using this IC. You really can't destroy it, but you can certainly delaminate (kill) the PCB if you heat it for excessive amounts of time. Don't 'not' create a PCB or a design because of silly SMD parts. They're not that hard to solder!


Battery Backup

12mm coin cell holder

If you're playing with GPS, you've got to have a battery backup. The 12mm coin cell lithium allows the PG31 (and many other GPS receivers) to retain the alamanac data. This small battery provides just enough juice for 3-5 years. By having alamanac data at power on, the GPS receiver will be able to do a warm lock instead of a cold lock. Cold locks take 1-2 minutes, warm locks, as little as 30 seconds. The alamanac data, in effect, allows the GPS receiver to 'guess' where it is in the world ("Last time I was on I was in Ohio, therefor, I will assume I'm near there").

If you're unfamiliar with Lithium Coin Cells - they come in a couple different sizes. I prefer 12mm just cause it's small but beefy enough to do most of the BBR (battery backed ram) that we need to support. The battery itself has a postive top (noted by the plus) and a ground on the bottom. You normally create a pad on the PCB for the ground and the coin cell holder is positive. We've learned the hard way that the bottom part of the cell is sometimes concave. This means that when you slide the coin cell onto the board, the concave ground part of the cell may not contact the PCB pad very well. If you're using a paste stencil, just leave a cutout for this pad. The extra paste will add 5-10 mils of solder to the pad. If you're solder the thing by hand, add a little blob of solder to this ground pad to give it some height. When you insert the battery, it should ride nicely on top of the ground pad blob.


PG31 Footprint

PG31-Footprint.jpg

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 when engs hate to change parts...


Final Layout

PG31-USB-Layout.jpg

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 CP2102 IC 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

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.

We may consider migrating to a different USB IC someday but the CP2102 continues to be a really simple to use USB to UART IC.


Documents

PG31 USB Schematic

PG31-USB Protel File

PG31-USB Gerber Files

Footprints:
SFE Footprint Library

FP Name: PG31

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

Related Items:

Personal tools
Namespaces

Variants
Actions
Navigation
Toolbox