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Mr.RC-Cam

For Sale: Etek EB-85A 5Hz GPS Modules. CHEAP!

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Aug-13-2007 UPDATE: My special sale is retired.

Nov-2007 Update: The EB-85A (with the latest firmware) is available from dpcav.com for about $81.95 USD. Sparkfun.com has them for $99.95, but it would be best to ask them if theirs has the new firmware (you'll want M-core_1.85).

BTW, the new firmware allows the user to change the power-up default settings using the Mini GPS (version 1.41) PC software application tool. So, you can customize the power-up default baud rate and update rate to suit your application. This is a new feature that was introduced with the M-core_1.85 firmware, which was released Sept 2007. ETek can reflash older EB-85A modules and existing users can contact the ETek factory sales office about that if they would like the firmware upgrade.

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Old discussion starts here (but please remember that I retired this special offer).

I have a small quantity of fresh-from-the-oven Etek EB-85A 5Hz GPS modules. Includes the cable. While they last, $XX each plus shipping. For international ship rates, please PM me with your country.

These GPS modules are very tiny (same size as the Globalsat EM-411's). The following documents and PC demo software apps are all that appear to be available from the mfg:

Full documentation and a cool EB-85A PC application is available from the dpcav.com site: Click Me!.

post-15-1176481071_thumb.jpg

Edited by Mr.RC-Cam

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I would like one of then, only one question for it. Is it fixed the lost of satellites when you put it close to lawmate transmitters? I know that in the em406a there is that issue, and no issues at all with airwave transmitters.

THX

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mr rc cam i admire your work i recently bought the inspire osd from dpcav i think thats ur work right? anyways i would like to add real time tracking from a base station using the tinytrak plus(tinytrakplus.. my question was would this gps unit work with that and if so i would like to ask you how thw wiring went to the dbp connector the tinitrak accepted since i dont have alot of knowledge with electronics but i am a fast learner and follow directions as i did with the inspire.... i would like one of these receivers for that project. thanks for all your help

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Are they true 5Hz? There are no commands to set 5Hz fix rate in the Command Set (per link).

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i would like to add real time tracking from a base station using the tinytrak plus(tinytrakplus.. my question was would this gps unit work with that

I don't think so. The Tinytrak baud rate is fixed to 4800, and the 5Hz Etek uses 38.4K baud.

Are they true 5Hz? There are no commands to set 5Hz fix rate in the Command Set (per link).

Well, they claim 5Hz operation. From what I understand, the update rate is slaved to the baud rate. 5Hz requires 38.4K baud, which fortunately is the default setting. In addition, it may (or may not) require disabling some unneeded sentences. I have not had time to power one of these up, so I am not going to be much help.

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I don't think so. The Tinytrak baud rate is fixed to 4800, and the 5Hz Etek uses 38.4K baud.

Well, they claim 5Hz operation. From what I understand, the update rate is slaved to the baud rate. 5Hz requires 38.4K baud, which fortunately is the default setting. In addition, it may (or may not) require disabling some unneeded sentences. I have not had time to power one of these up, so I am not going to be much help.

If we see the catalog sheet you posted, it says that the default baud rate is 4800 and if it´s not set up you could adjust it. So I guess it would work perfect with tinytrack

http://www.rc-cam.com/misc/EB-85A_Catalog.pdf

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If we see the catalog sheet you posted, it says that the default baud rate is 4800 and if it´s not set up you could adjust it.

Thanks for the correction. I had read elsewhere that it was factory configured to default to the 38.4K baud rate. Since I didn't trust the data sheet, I wired one up this morning. It is indeed 4800 baud 1Hz default.

I don't have an official document for the host's PMTK commands to set other baud/update rates. But, here is the command set used in a similar GPS; this doc includes MTK's baud and update rate syntax (maybe they will work with the EB-85A): PMTK Commands (Click Me!)

Otherwise, you could utilize the battery backup feature and setup the EB-85A using the PC based utility software to set alternate configurations. Once removed from the PC, the settings would be retained via the battery.

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In the MiniGps program supplied there are separate options to set baudrate and update rate anywhere between 1 and 5Hz, pretty cool. It can also give you the used RS232 bandwidth from your sentence/update rate settings. Pretty cool.

If the doc is unavailable, you could use one of those RS232 spying programs to grab the commands coming from the PC software and reproduce them in your application too :)

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Here are some example commands to control the EB-85A (I have confirmed that these do indeed work):

Set to 38.4K Baud:

$PMTK251,38400*27 <CR> <LF>

Note: Send the command at 4800 baud, then switch the host to 38400.

Turn Off all sentences except GGA and RMC:

$PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28 <CR> <LF>

Note: there are 19 NMEA fields used in this command. This is per the chip set doc.

Turn On WAAS:

$PMTK313,1*2E <CR> <LF>

$PMTK301,2*2E <CR> <LF>

Set to 5Hz sentence Updates:

$PMTK220,200*2C <CR> <LF>

If your host is not setup to wait for the command acknowledgements, I suggest that you put short pauses between commands. Also, on power-up {before talking to the GPS} wait a second or more to allow the GPS to initialize.

If you need different command parameters then just use the MTK manual. Links were provided in an earlier post.

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Do you know if WAAS is enabled by default?

Sorry, but I don't know. I assumed it wasn't, just to be safe.

I forgot to mention that the <CR> <LF> at the end of the commands are not text. The <CR> is a carriage return (0D hex) and the <LF> is a linefeed (0A hex). These must be sent at the end of each command.

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WAAS only work in the US

how the module works and respond without it we have to find out soon,

when my EB85 arrive

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Without WAAS (in Europe) it seems to work just fine

5Hz updates on an OSD of waypoint heading, distance, and altitude are really a pleasure to fly with :-)

I have noticed a couple of strange things. Firstly, the modules shipped from SparkFun seem to default to 38,400, not the 4,800 reported earlier in this thread.

Secondly, the SparkFun modules seem to ignore $PMTK314, still investigating...

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Without WAAS (in Europe) it seems to work just fine

5Hz updates on an OSD of waypoint heading, distance, and altitude are really a pleasure to fly with :-)

I have noticed a couple of strange things. Firstly, the modules shipped from SparkFun seem to default to 38,400, not the 4,800 reported earlier in this thread.

Secondly, the SparkFun modules seem to ignore $PMTK314, still investigating...

I received one from Sparkfun that defaulted to 38400 and one to 4800.

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I received one from Sparkfun that defaulted to 38400 and one to 4800.

That is good to know. Looks like I need to change some code to accommodate that.

My only experience is with the EB-85A. Is there a chance that the default 38400 baud version is a EB-85?

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Mine is certainly the 85A. I didn't try it yet, but I'm wondering whether $PMTK390 could explain the difference, or maybe $PMTK590.

(assuming that these are implemented on the 85A)

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Those two commands would affect the default settings. Maybe Sparkfun utilizes them before shipping a new GPS? I will say that they are very scary looking due to the write count limitations. I have not tried them for that very reason.

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I got mine from Sparkfun and it too was defaulted to 38400.

On a bad side of things: changed settings (like sentence selection) only stay on for few hours even with the battery backup.

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I got it !! thanks for an amazingly fast deal !!

I only use com port 1 pin 3 and 4

4800 default, and GLL, GSA, RMV, GSV, VTG, GGA is ON at 1Hz update,

if I change to something else, also the baud rate,

and recycle power, all is back to my default, no battery attached yet.

using the mini GPS setup utility is a bit strange, but I can actually set the update to 2 hz and 3hz and so on if I like, not only 1 hz or 5hz as others have seen.

Edited by ThomasScherrer

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Turn Off all sentences except GGA and RMC:

$PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28 <CR> <LF>

how did you calculate the checksum ?

This is what I need:

Turn Off all sentences except GGA and VTG:

$PMTK314,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28 <CR><LF>

have you tested it does not need <CR><LF> BEFORE the commands ?

like the EM401 modules needs to be ready ?

My EM85 accepy commands fine, even if they start with crud in fron of the command:

blablahello$PMTK314,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28 <CR><LF>

works fine

Edited by ThomasScherrer

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how did you calculate the checksum ?

It's the usual method. XOR all the data bytes between the $ and checksum.

$PMTK314,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28 <CR><LF>

have you tested it does not need <CR><LF> BEFORE the commands ?

No, I have not tested it without the sentence termination. According to the doc's, the CR/LF are mandatory. They tell the module to execute the string. But, maybe the docs are wrong (not unusual for Far East created technical info) and instead they can be omitted. Just try it.

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a really cool module, smart to have all the setup sentences in one word !

it is just as sensitive to VHF radio as my EM401, darn,

I can not talk with my friends on 145Mhz with any unmodified modules.

I will make some compare with 2.4Ghz next weekend.

how about the cold powerup to lock ? is it me that is unpatient ?

or is the EB85 really sooooo much more slow ? over 10 mins ?

Edited by ThomasScherrer

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