I can't seem to get it to lock outside on a clear day. I'm using an mbed controller wired up exactly as it is in the example.

$GPGSV,1,1,00*79
$GPRMC,195258.455,V,,,,,,,180212,,,N*43
$GPGGA,195259.455,,,,,0,00,,,M,0.0,M,,0000*51
$GPGSA,A,1,,,,,,,,,,,*1E
$GPRMC,195259.455,V,,,,,,,180212,,,N*42
$GPGGA,195300.455,,,,,0,00,,,M,0.0,M,,0000*5C
$GPGSA,A,1,,,,,,,,,,,*1E
$GPRMC,195300.455,V,,,,,,,180212,,,N*4F

This is what the data looks like that I'm getting. As you can see with the GSA messages it is saying that lock is not available. I'm using this device outside with a clear sky and it is wired up exactly as shown in demonstration. Any ideas?

This is what it shows when I power cycle the gps. $PSRFTXT,Version2:F-GPS-03-10062312A $PSRFTXT,WAAS Enable66 $PSRFTXT,TOW: 59402718 $PSRFTXT,WK: 167560 $PSRFTXT,POS: 6378137 0 02A $PSRFTXT,CLK: 9625025 $PSRFTXT,CHNL: 1273 $PSRFTXT,Baud rate: 480065

I tried an external power supply from the lab at my school that was isolated from the 5V supply from the mbed controller and still no lock. I walked around my block, even put the device in my truck on the dash and drove for a half hour thinking movement would help it and still no lock. The device just has the solid red light that never blinks. Is it possible my device is bad?

It did its first cold start acquisition from my bench top in under 30 seconds. My trusty old Garmin takes forever to lock up from the same location. The little LED indicator is really helpful too.
The Serial interface is not RS232. It is TTL level and inverted from normal RS232. The serial signal is 8 bits, no parity and one stop bit. Or at least that's what works for me.

I do a lot of rockhounding in the deep forest, hills, remote areas, canyons, etc...
This GPS engine really shines, easily handling conditions which throw Oncore VP, STMicro, Asin, Rockwell Jupiter, and other engines I have used, into an endless search for over half an hour with not even a 2D lock (I have a few spots I like to stop and test engines at, while eating lunch).
Later, I wired in a Lucent Quad-Helix GPS antenna, and on a few mountainous/canyon treks, which in the past have left hundreds of bread crumb track tidbits, due to the loss of signal with the very same antenna, I got a single continous trail log.
Highly recommended, it ROCKS!!!

Every time I hook up my this GPS module to my arduino using the breakout board here https://www.sparkfun.com/products/11818 the arduino turns off and when connected to my computer displays a message saying that it was drawing too much current. The LED was blinking in the beginning but I cant get it to work since. I hooked it up using this diagram/tutorial http://bildr.org/2011/06/em406a-gps-arduino/. Please Help!!

I purchased this GPS, an arduino YUN, and the GPS shield from this cite. To my understanding it is the same as the GPS Retail Kit sold here too. However, when i go to run any code to test the GPS i have NO CONNECTION. Another user said i needed to convert from RS232 to Serial, but i havnt found anything about that in any online guides. Is it possible i have a bad RX-TX connection? how can i test to see what is and isnt working?

Greetings all-can't get new unit to lock or generate any output after two hours in the window--the red light flashes every second. GP-635 locked right away as did another GPS module, so wiring and reception appear to be okay.

SiRFDemo solution looks interesting but can't figure out the software option--I'm current running a very simple sketch [loop(); setup();] on an Uno and can't establish communications.

DOA, perhaps?

I have the SparkFun GPS shield and the 406 GPS unit. I have confirmed connection between the GPS RX to Arduino TX and GPS TX to Arduino RX with an ohmmeter. I'm running the current example sketch listed under the GPS Shield listing but I get no data. I do get:

GPS Shield QuickStart Example Sketch v12

waiting for lock

But nothing more. I have open skies and the activity light on the GPS is flashing away but after 7 minutes still nothing is printed out on the serial monitor other than the above two sentences. I have confirmed +5v and GND on the GPS 406 plug to the Arduino board. The sketch compiled OK with no errors. I'm using the UNO board and power through the USB from my laptop. Switch is in the DLINE position and the ON/OFF switch is in the ON position. Does the case of the GPS unit have to be totally insulated from the shield? I mounted it with thin double sided tape but on the prototyping area which I assume is not connected to anything. I may try some double sided foam tape to lift it above the board to see if that could be causing a problem. My old Garmin gets a fix in a minute or two in the same location. Does anyone have any idea of what the heck is going on here? Also posted on the GPS Shield page to cover all bases.

I want to interface this GPS with a MCB1700 board (LPC 1768 Microcontroller onboard) through UART. Do i need to use a logic level shifter to interface. The pin on the board says this

"5v Tolerant pad providing digital I/O functions with TTL levels and hysteresis. This pin is pulled up to a voltage level of 2.3V to 2.6V"

How much voltage does this GPS receiver ouput? Does it require level shifter to interface with a microcontroller?

Has anyone been able to interface this GPS module with the SiRF demo software (for re-configuring the module) through the Sparkfun GPS shield (v14) and an Arduino? And if so, how? Thank you.

sentryGun53 :

1) launch SirfDemo

2) select Setup/data, choose the COM port

3) select Action/Synchronize protocol & baud rate

4) select Action/initialize data source,check Factory reset

Measured with an MSO-28 USB scope, the PPS pulse is 1.1 µs wide and 2.8 V high.

In NMEA mode, the module work fine at 57600 baud :

$PSRF100,1,56700,8,1,0*36

and at 115200 baud too:

$PSRF100,1,115200,8,1,0*05

While trying to change the baud rate of this module, I think I mistakenly set the protocol to SiRF by sending this command:

"$PSRF100,0,19200,8,1,0*39\r\n"

Now, I can't get the TinyGPS library to read the incoming data at either 19200 baud or the default 4800 baud (which was working fine before I sent the command).

How can I set this back to NMEA at 4800 baud?

can this be integrate with an fpga?

how can I find the baud rate of this gps module?

The link to the GPS Tutorial by Michael Simpson appears to be broken.

Re My last comment.

I meant - Because the 1pps pulse is very narrow, many scopes will not detect it.

Can anyone tell me what the default paramaters are for the TX port? I have an application which just needs to read the NMEA data - not transmit anything to the GPS. I need to know what to set the port parameters to.

Is it true that if I am not using the RX port on the GPS I must pull the port up? There seem to be a couple of versions of the datasheet about, one says to do this, another doesn't say anything.

Lastly, I tried to look at the 1pps output on a scope to verify it was there. My scope cannot see it. Like many other GPS rx the duration of the pulse is very small so some scopes will detect it. So I used a probe connected to an audio amplifier and could hear 1pps "clicks". So I assume this helps. I guess you might be able to do this with Walkperson earphones at a pinch.

It is a very nice little unit and much easier to get results with than some of the "old school" Trimble boards I have. if only the documentation was better....

Regards,

Steve

I'm having lots of difficulty getting valid data with this module, it seems like every 5 or so sends across the UART are valid. Any reason for this?

EDIT: data's not actually valid, it sends this: $GPGSV,3,1,12,22,57,351,,29,56,166,,14,54,179,31,06,51,298,7C
$GPGSV,3,2,12,21,51,062,26,18,38,030,,03,29,310,,32,19,253,7A
$GPGSV,3,3,12,15,16,040,,16,16,259,,30,10,224,,09,09,079,7B
$GPRMC,100517.441,V,,,,,,,180612,,,N42

does anyone know what the maximum altitude is for this receiver?

In case anyone is curious, the factory confirmed that these modules have static navigation turned off as default.

This GPS receiver hooks up directly to a Nikon D7000 or D90. Both the output voltage of the Nikon (5.9V) and its input level match the specifications. I soldered the cable to it and it worked immediately. No additional components were needed (http://emergingdrake.blogspot.com/2011/10/gps-for-nikon-d7000-or-d90.html)

If anybody is curious about using this module as a clock reference, you can get ZDA messages using this command:
$PSRF103,08,00,01,00*2C\r\n

Does anybody know the technical name of the end connector used on the EM-406A cable. We need to order a female plug to fit on a PCB we are designing around this GPS.Cheers.

Mine came in a free stuff box unpackaged and the thingy on top is crooked. Can it still be used?

Just wondering, I'm using this GPS with an arduino, and want to know if it's possible to put the GPS into standby or reduced power mode without powering down the arduino. I'm fine with it reacquiring signal when it the GPS is powered up again.
How would i do this?
Thanks!

I'm getting different TX levels (on pin 4) when I measure pin 4 directly on the EM-406A (from 1 vdc up to 3vdc) and when I measure the TX pin on the output of the evaluation board, < +.5vdc to > -5vdc. My application works fine when receiving signals from the eval. board but not direct from the GPS. Is this normal?

I purchased an EM-406A GPS with evaluation board. Got good nav "fix" in the basement right out of the box. Ultimately, I want to mount the EM-406A (without the evaluation board) in a vehicle which will supply NMEA data to my APRS Byonics "Pocket Tracker" -- which works fine on the bench when receiving data thru the DB-9 connector on the eval board -- but when operating the EM-406A without the evaluation board (even though the LED flashes indicating a GPS lock), the Pocket Tracker reports my coordinates as "!0000.000/00000.000". Any suggestions? Many TNX

Can this unit be wired to an arduino w/o the shield? I'm thinking of using this with an Arduino Pro Mini 328 and am trying to aim for a tiny form factor.

I have the EM-406A working with an Arduino board (No sheild), I am able to read everything and the position is lock.
My question is about the pin6 that provide 1 pulse-per-second. I am trying to see the pulse on a scope (I am probing between pin 6 and pin 1) but I have nothing, do I need to put a pull-up resistor on pin 6 in order to get the pulse? If the answer is yes, what would be the value of this resistor?
Thanks

Would there be any reason why I couldn't connect the Vcc to a data pin on an arduino mega so that I can control it via a data pin, or do I need to use a transistor to control it? I've tried it on a breadboard and it seems to be functional, but I'd hate find out that it will end up drawing too much power down the line or something.

Handy setup strings for the EM-406A:
<br />
<br />
*
NMEA 8N1 various baud rates:
<br />
$PSRF100,1,1200,8,1,0,*2D
<br />
$PSRF100,1,2400,8,1,0,*28
<br />
$PSRF100,1,4800,8,1,0,*22
<br />
$PSRF100,1,9600,8,1,0,*21
<br />
$PSRF100,1,19200,8,1,0,*14
<br />
$PSRF100,1,38400,8,1,0,*11
<br />
<br />
Debug On:
<br />
$PSRF105,1,*3E
<br />
Debug Off:
<br />
$PSRF105,0,*3F
<br />
<br />
Select WGS84 Datum:
<br />
$PSRF106,21,*0F

I left the example program run for a half our and no fix. Anyone else have the problem? I printed out the data coming in from newsoft serial and it looks like valid NMEA data, just not acquiring any sats.

Does Sparkfun leave these modules set at the factory defaults of 4800 8N1 NMEA protocol as shipped from Sparkfun, or does Sparkfun reconfigure them prior to shipping?

I would be very interested to see if anyone has written any elegant code to translate the Lat/Lon data into UTM (Universal Transverse Mercator) format.
Is anyone aware of such code?
I looked into writing some myself and the formulas appear to be pretty messy, so I figured I'd check first rather than waste a lot of time doing what’s already been done.

Can anyone comment/help me understand the 5m accuraty with WAAS in the feature set? I have the EM-406A module, and not sure how to enable this (if possible).

_
_

I'm thinking of deploying this (EM406) module on an ocean buoy hooked up to some telemetry so that I can check on the buoy's position.<br />
Does anyone have an opinion as to whether or not the normal wave action (not a storm) will allow the module to achieve a lock? Thank you, Marc

Is it possible to pull out raw GPS measurements from this chip. Such as pseudorange measurements witha PRN number of the transmitting satellite. I would also appreciate a web link to highly detailed documentation of data that can be pulled out from this ship set. THANK YOU :)

I did some fields measurements.
Conditions:
- unit stationary
- clear sky, no obstructions
- position sampled 391 times
Results:
Radius of circle enclosing 50% of the samples: 0.76 m.
Radius of circle enclosing 95% of the samples: 2.05 m.
All measurements were within a 2.3 m (lat) X 2.5 m (lon) rectangle.
Notes:
1. The circle centers are the sample mean. The sample mean itself was in error by about 1 m, per inspection on gpsvisualizer.com.
2. The unit has a resolution of 1e-5 lat/lon, or about 1 m.

Here is a essential web site to get you started fast ====> http://arduiniana.org/libraries/newsoftserial/

Be sure to get the corresponding GPS Shield. The connector is MORE than mildly inconvenient. I'd go so far as to say the pins are 'inaccessible' without the GPS Shield.
Anybody have a source for the receptacle of this cable? I'm having a hard time sourcing one in Los Angeles.
I guess one could cut the end off and solder on you're own wire, but I doubt this is a recommended solution.

This unit makes GPS very easy with Arduino, have a look at the things I made with it here - http://wp.me/pQmjR-Ty

Mine takes up to 2 minutes to start streaming data if I haven't turned it on in a while and if it's more than a couple hundred feet from where I last turned it on. Other than that it works exactly as described. I've found that the TinyGPS arduino library is extremely helpful for parsing the NMEA data: http://arduiniana.org/libraries/tinygps/

Not sure if anyone else has had this issue but this unit is returning very precise information... it's just not accurate. My position is consistently reading about 20 miles south and 5 miles east of where I really am.

PUBLIC SERVICE ANNOUNCEMENT: THIS UNIT WILL NOT WORK AT AN ALTITUDE OVER 18000 METERS (60000 FEET)
This unit uses a Sirf-III GPS chipset has a limitation that buyers should know about. THIS UNIT WILL NOT WORK AT AN ALTITUDE OVER 18000 METERS (60000 FEET). This doesn't matter to most people, but is important to hobbyists that take part in high altitude weather ballooning, amateur rocketry, etc. Someone I know mistakenly purchased a Sirf-based unit for ballooning and I'm hoping to save people from making the same mistake.
I'm going to post this in the comments section of all the Sirf-based Sparkfun products in the hope of saving someone from from making the same mistake. I apologize if the Sparkfun guys consider this spamming, that isn't my intent. It, also, isn't my intent to drive business away from Sparkfun. They have an awesome collection of GPS products and many of the other modules don't have this limitation.

I'm wondering if anyone could point me in the direction of information concerning the considerations involved in choosing/designing an enclosure for a GPS module such as this one.
What sorts of materials are the GPS frequencies particularly transparent and/or opaque to? How direction dependent is the reception of the ceramic antenna?
Both experience and experimental data welcome.
Thanks,
Ian

Greetings,
I want to reduce consumption GPS module without disconnecting the power supply so as to allow a hot start when prompted and the position within 1 second.
thank you very much.

It's fantastic!
Just bought, Powered inside my home, near a windows, and in 12 seconds it found the signals!
I'm using in my system of telemetry!
http://sites.google.com/site/ricolk32/telemetria