No, there is something wrong - it will retain location and time for a minute or two, but not much longer, then it has to do the cold start.

Can we get a schematic for the SUP500F or is it just breaking out the Venus and adding a chip antenna?

2 weeks before AVC and you do this to me Sparkfun?!

im trying to find a reason i'd need 65 channels, when theres only 58 gps satellites and you cant possibly see more than 1/3 to 1/2 of them at once... love the through-hole connection though!

Worst GPS Ever

I'm a bit sorry to see this dropped from the catalog, although I understand that many users have been having trouble. I bought one a few weeks ago and it's working fine now, although I had a couple of hurdles to get over. I have it mounted on an SD shield with an Arduino UNO.
One hurdle was that the serial output of the device cannot be directly input to the RX port of the UNO. The RX pin is pulled high by the USB interface and the drive of the SUP500F is not sufficient to overcome this. I put a TTL chip between the GPS and the RX port and that worked. The second issue only partially understood by me. I have the PPS output connected to pin 2 for use as an interrupt and also connected to a TTL latch. The GPS does not power up properly in this configuration without modification. If the TTL chip is pulled out of the circuit, everything powers up find. If the PPS line is wired to ground when the board is powered, everything works. I don't understand this, but I put a resistor and capacitor between the PPS line and ground and thing power up just fine. Somehow putting a load on the PPS line for a short time after power up makes things work.
If someone has one of these and is still having trouble, I'd recommend powering the device with the output pins unloaded to see if data is there when the output pins are then connected for monitoring. Some users said that they did not get a GPS fix, but I didn't see (or overlooked) any observations of what the NMEA output is during this time. When the device works, NMEA output is there instantly. If there is no serial output, then the device did not power up correctly and no amount of waiting will help. The PPS only appears after a fix is achieved but the serial output data is there righ away.
I hope that these comments help anyone who already owns one of these and is still having trouble.

How bout altitude? How high can it go? >>>18km?

I recently bought this receiver and have had trouble with it. I have not been able to get anything out of it. I am using an Arduino Duemilanove and connected power and ground of the receiver to the AD and connected pin 2 to Rx of the Arduino. I tried following the LS20031 Assembly Guide at:<br />
http://www.sparkfun.com/tutorials/176 <br />
<br />
but still had no luck. <br />
<br />
Any help please??<br />

Seems to work well, though not having much luck under anything but a clear sky. I used a MAX232 to do the RS-232 to TTL level conversion, and a voltage divider to get the output of the MAX232 down to the 3V needed for the module (I tried it briefly without the voltage divider and it seemed ok).<br />
<br />
Here's a quick writeup.

Doh... Found the button in the SkyTraq 0.4.503 software. The one at the bottom in the middle that says "Download". Who would have thought?
Stopped the GPS just in case. Uploaded prom.bin at 115200 baud, took longer to flash than to upload. Acts like a different GPS now. TTFF seems much faster. May store
last postion in FLASH on power down? I will try more different power up locations and see. THX Ken

How do you upload the firmware to the part? My GPS says 1.4.40, the update indicates 1.4.94. Is there any benifit to uploading the new firmware?
Seems to work well. A little slow to first fix from cold start. Altitude very slow to settle (compared to other units), MAP330, Garmin something, Magellen car model.
Linked configuration software works great. Change in SRAM if you are chicken, commit to FLASH after it works. I got the PPS at 4 second rate before I tied the backup power pin to 3.3V and the mode with a pullup. THX Ken

When I provide this module with 5V, the 1PPS pin pulses every 4.1s, forever.
The module has a good view of the sky, so it should acquire synchronization. This is the first time I switch this module on.
Has anyone experienced the same thing?

Also curious if there's any prediction for when this will be coming in?

any idea when these will be back in stock? I really need one soon for a science competition experiment.

Can we mount this GPS module sideways? Will the sensitivity get affected if we have the patch antenna facing sideways?

Help needed
Hello,
I connected this GPS module to Arduino Mega as following
GPS TX > AM RX1
GPS RX > AM TX1
GPS GND > AM GND
GPS VDD > AM +5
GPS BAT > AM +5
And uploaded the following sketch
void setup(){
Serial.begin(9600);
Serial1.begin(9600);
}
void loop(){
if (Serial1.available()){
int inByte=Serial1.read();
Serial.print(inByte,BYTE);
}
if (Serial.available()){
int inByte=Serial.read();
Serial1.print(inByte,BYTE);
}
}
It was working perfectly when I use Arduino serial port monitor and also I was able to read and write to the module perfectly using SkyTraq 0.4.603 software. Then through SkyTraq software I set ?Configure Position update rate? to ?10Hz ? and the module started to send fast unreadable characters and I lost control of the module.
I tried to change the sketch to use 115200 baud it did not help, I disconnected the module for more than 2 hours then reconnected it but it remains on the same settings and when I try to control it using SkyTraq software, it give error that module is not responding. Anyone can help me on this?

I tried the QStarz 818XT 10Hz - the driver is wrong on the page, it does do AGPS but not SBAS (WAAS) at 10Hz. But it uses the MTK with 66 channels, so might lock in faster v.s. this.
If this module has the Venus chipset, it only has 12 channels, and can scan either 2 or 4 channels, but I've been using it with AGPS, SBAS, all at 10Hz, and it works as well if not better, though it might be a little less sensitive. That may just be the antenna.

One other thing - the Venus datasheet talks about adding a series and pullup resistor to the comm lines - are these in the module, or do they have to be added externally?

I am wondering about WAAS, too. The Sparkfun tracking comparison shows this one as having inferior accuracy. That may be because WAAS wasn't enabled.

Has anyone used the SUP500F with WAAS enabled? If so, how is the accuracy? Did it improve much with WAAS on?
I am considering using 2 of these modules and taking the differential position for heading measurement, and I wonder if this is reasonably likely to work or going to have huge amounts of noise.

Great. So where can i locate that sparkfun library?

I love this gps module. Works nicely with my arduino projects. But are there any eagle library file for this item? Would be nice to use with my schematics and pcb design.

May I connect the shield dummy pads to ground?

Well I got this GPS working with an Arduino, thanks to the great support given my Mike and the SparkFun tech support! SOrry I left a bad comment before. The problem with interfacing this chip with an arduino is that the arduino serial lines read 5V serial data, and the GPS chip only output at about 2.8 volts, not quite high enough for the arduino to pick up. You have to boost the voltage on this serial connection and then it works!

I am Trying to set this up with an arduino, with the just tx GPS pin connected to the rx arduino pin, the power pins connected to 5v and pin 5 to 5V. i am just setting it up to Serial.Read() from the arduino @ 9600 bps, and I get nothing? Sparkfun Tech support stopped replying to my emails this week. Any ideas? I am beginning to think this is just a conversation piece.

I am a bit disappointed...:
This is the first time I am using GPS, but results seem to be pretty bad. The SUP 500F is configured for 10Hz GPGGA output @38200 baud. Hor. dilution of precision was around 1.2, around 7 satellites were tracked (free view to the sky, good weather etc.). And this is the position (I stayed 1 min on the same spot):
http://www.villalachouette.de/william/krims/tricopter/websitepics/sup500_gps.jpg
Here, I was driving with my car (NOT through trees and houses, I promise...):
http://www.villalachouette.de/william/krims/tricopter/websitepics/sup500_gps2.jpg
Is this all I can expect from GPS? I want to use it for position-hold for my tricopter design (http://shrediquette.blogspot.com), but it won't work the way it is now...

I am having problems getting this unit to talk.
I am using a RS232 Shifter SMD.
Rx from SMD to Tx on gps
Tx from SMD to Rx on gps
VDD is at 5V
Vcc on the SMD is 3.28V for the TTL level.
pin 5 is connected to the 5V
I am using the Sky Traq software 0.4.603
In the software it sayes it is connected but i an not getting any data from it.
Do i need pins 6 and 7 connected to any thing?

I have just received a unit and got it communicating with the GPS Viewer software. (Using FTDI cable - 5V). Power to the module is 5V and Advanced acusition is enabled.
Set the update frequency to 4Hz and baud rate to 115200.
I have sucessfully updated the AGPS also.
The problem I have not is with the cold start. If I point the receiver outside my window, which has a 80 degree view of the sky, I never got a lock (tried all the Cold, Warm and Hot start). I actually have to go out in the open, have a very clear view of the sky, and then wait 30+ secs, then I get a lock.
For my phone with built in GPS module, I can even get a lock even if I am standing inside the window.
How do I get it to start when it has less the a "clear-sky view"?

I'm having a problem with this module.
Configuration is :
FTDI 3.3v cable
cable TXD (orange) connected to module Pin 1 RXD
cable RXD (yellow) connected to module Pin 2 TXD
cable GND (black) connected to module Pin 3 GND
cable VCC (Red) connected to module Pint4 VDD
no other connections:
using tera term 9600 N81 - I don't see any data
using GPS View_0422-1 - I don't see any data
Any Ideas ?
Thank You

This is a relatively general question, but what is the best way to use this with a 5v arduino? Sparkfun's logic level converter is sold out. My initial thought was just to use a voltage divider from the arduino to the gps, then hope that the arduino would recognize the 3.3v coming the other way. Any insight would be great.
Thanks

I have a display in my car that displays various engine values and most important the speed at 2 Hz .
I read only the RMC @ 19.2kbps @ 2 Hz .
The SUP500F ,
Very fast Time To First Fix about 30sec , but occasionally does not find satellites when standing still . ( This problem did not occur in neither the LS20031 or the FV-M8 )
Consistent readings accelerating and best tracking of slowing down fast .
Occasionally ( During the first minutes after power up ) displays speeds way off . ( This morning it indicated i was driving at 1052 km/h ... in 15-20s returned to normal )
The FV-M8 ,
TTFF about 90s .
Good and consistent speed readings . Except with fast temperature changes .
Another problem with this module is the forgetting of settings even when there is a battery connected .
I have had this GPS installed for 4 months and i have had to re-set the settings at least 15 times now .
( I have observed the GPS losing settings just after power up and about a minute after power up )
The LS20031 ,
My opinion : best GPS of the three on the long run ...
TTFF 30-90s .
Good following of accelerations , not as good on slowing down .
Internal battery , almost as good as Flash .

I'm losing my nerve ...
How do i change the baudrate to 19.2kbps , and the output string to only RMC @ 2 Hz ???
Please help !
I have tried every GPS program i can find ... even MiniGPS failed , it reads correctly but does not change any setting ...

The unit does have WAAS, but its off by default.

I think that most china maker can write 100 channels. but really not any words about A-GPS (and other). Now i decide design PCB with U-blox G100/200 module and NEO-5 GPS adapter. With ALM-1712 GPS amplifier it's really work with only 1/8 open sky and with A-GPS from U-blox works w/o lost GPS satellite signal. I think desing pcb with arduino compatible pins and also adopt a leaflab maple platform (STM32) - projects on their site has some principal error but not a fatal. GSM/GPS with U-blox design as standard arduino's sizez board and now it complete. Currently work with correct STM32 arduino board. All news and files available at http://akb77.com/g (2-3 days to complete)

I assume this unit has no WAAS capability (not mentioned in the spec sheet.) If so, it seems the LS20031 GPS 5Hz Receiver might be a better choice, other than for the slower update rate.

This is not a surface mount component and yet no mounting holes. Are users expected to let it hang on those wires?

http://www.cyberitech.com/gps.htm

The documentation is a bit sparse... No mention of how to set the baud rate, what commands is responds to (send to unit), or even who the manufacturer is.