Questions tagged [gps]

stands for Global Positioning System, a satellite based navigation system

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6
votes
1answer
2k views

GPS consideration for PCB with GSM (interference, setup etc)

I am working on a project which has a GSM and GPS on the same PCB (fairly near each other in an enclosure). Since I am not familiar with GPS I was wondering if any of you could give me some tips on ...
0
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1answer
1k views

Generating Hexadecimal checksum for a NMEA (PMTK) message

I am trying to use quectel L80 GPS receiver for my project. I am trying to configure the L80 using the PMTK strings. But the problem is the string should also contain a hexadecimal check sum. eg. $...
8
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1answer
2k views

how is the 1PPS signal generated in GPS receivers?

The question might seem stupid, but the time of flight from the satellite is unknown and moving, the doppler effect is skewing the frequency (and is not constant due to the relative trajectory) and ...
0
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2answers
1k views

GPS 1 PPS Aligment Clock Signal Generator

i want to do GPS 1 pps aligment clock signal generator. Clock signal should be at 24.576 Mhz and voltage level Vmax= 3.3 V and Vmin=0 V DC. How can i do that? It is very important to align between GPS ...
0
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3answers
987 views

SIM908 GSM and GPS modules individual power control

I've been searching around google and even in manufacturer site for this information and found nothing relevant. Is it possible to turn off GSM module and keep turned on the GPS? How can it be done? ...
2
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2answers
2k views

SAW and GPS Antenna

I'm designing a system with a GSM modem and GPS receiver. In order to achieve out of band rejection I'm planning on putting a SAW filter right after the antenna. Often on the internet I see a few ...
4
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2answers
203 views

Capturing a 16.368MHz data stream with a MCU running at 32MHz

I have a 32MHz MCU (Atmel XMEGA A4) and I need to recover a digital signal coming from a GPS front end chip which is outputting SIGN and MAGNITUDE data at 16.368MHz. Clearly this is a hell of a task ...
0
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1answer
414 views

GPS gives weird characters when powering my ATMEGA328 on and off?

i got a problem with my GPS controlled by ATmega328, when i download the code using arduino ISP the GPS works fine and the lcd displays correct data, but when i remove the power from the atmega328 and ...
3
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2answers
181 views

Is GNSS S/N equivalent to C/N?

I work in developing software that integrates with GPS and Galileo receivers. I've struggled for years with inconsistencies in documentation for the NMEA emitted by such receivers, and I've decided to ...
0
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1answer
210 views

Is anything wrong with my PCB?

I am designing a PCB and I just want to make sure nothing is wrong before I send it off to the fab house. If one of you knowledgeable stack exchangers could give me some feedback, I would really ...
0
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1answer
841 views

What type of connector is this Velodyne interface box GPS connector?

Velodyne VLP-16 lidar's interface box has this connector. What type is it? Could not find this from the manual.
0
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1answer
1k views

Antenna gps neo 6m

I am designing a pcb which has the module ublox neo 6m, instead of using the normal antenna I was looking to use a ceramic which should work with ublox. I have got this: http://uk.farnell.com/...
0
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2answers
123 views

Ways to communicate GPS coordinates to a central server wirelessly from a wearable device

I am currently looking at designing a wearable device for a client, which can communicate GPS coordinates back to some sort of central server (to then be sent out to other communicating devices such ...
-3
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1answer
534 views

External GPS antenna for smart phones [closed]

Is there a smartphone GPS boost or external GPS antenna commercially available for smartphones. To hook up to smartphones via audio input for example?
2
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1answer
2k views

GPS antenna ground plane design considerations and limitations

I have a PCB design which incorporates a GPS unit. I'm looking at refining the PCB, and I'm looking to do away with the long cable length, occupation of space within my enclosure, current consumption,...
4
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1answer
3k views

Help to understand/ explore small sized 3G and GPS Antenna Design

I recently came across an exciting device called Automile, from Sweden and what caught my eye is this - I am really impressed by the packaging and overall quality of hardware integration they have ...
2
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1answer
803 views

PIC24FJ128GA202 UART2 and UART3 not working?

I am working in pic24fj128ga202 microcontroller with L80 and M95 module. here L80 module connected with uart2 and M95 module connected with uart3. now uart1 working normally but uart2 and uart3 not ...
4
votes
1answer
771 views

How is impedance matching for chip antennas practically done?

I designed a PCB for a GPS tracking device and i want to further develop it to have a smd gps antenna mounted on the board. I know that for optimal signal transfer i need to design a matching circuit, ...
0
votes
1answer
90 views

Reducing GPS coldstart if we know where the user is

I'm working on a project with GPS and I was wondering if it would be possible to reduce the cold start time by passing in some data. Let's say I already had a fairly good idea of where the user was ...
1
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1answer
465 views

Turning a frequency locked loop into a phase locked loop

I want to use a GPS module (with a PPS output) to ultimately generate a 5kHz timing signal that is phase-aligned with the PPS positive edge. ...
1
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1answer
8k views

How can I accurately estimate the power consumption of a GPS tracking device?

I'm building a solar powered GPS tracking device using an Ieik Mini Nano V3.0 Atmega328p Board (based on Arduino Nano), Adafruit Fona GSM module, Ublox GPS module. The GPS module will transmit ...
2
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0answers
497 views

Isolation between GSM and GPS antenna

We are doing a prototype for a gps based tracker. We got a problem in placing the GSM and GPS antenna. Both the GSM and GPS antenna are omni-directional antennas. In forums and application notes, the ...
3
votes
2answers
5k views

Material that Degrade GPS Signal Reception

Between clear tempered glass (see through,thick & very strong) Vs. coloured plastic material, which would result in more degradation of GPS signals if used to make a box? The box contains a ...
7
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6answers
4k views

Reradiating antena for GPS

I need to test and maintain a batch of devices which contain GPS modules. I can work on the rest of the device, but when it comes to test the GPS part I have no signal on my desk, no matter how near I ...
1
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1answer
129 views

How would you jerry-rig an android phone for continuous autonomous operation?

I want to use an android phone as dash-cam with GPS tracking capabilities. It is supposed to run 24 hours a day, 365 days a year. If the phone / app hangs, the user cannot be expected to ...
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1answer
829 views

Not getting data from Parallax GPS

I am trying to use a Parallax PMB-648 GPS with an Arduino Nano running this code: ...
24
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4answers
4k views

True GPS Location - At the Antenna or Receiver Chip?

Suppose I have a GPS unit attached to an antenna through a 50 meter coax cable. How would the location as calculated by the GPS unit be affected by the cable length? As a bonus question, how would ...
-1
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1answer
3k views

TinyGPS library doesn't update GPS data when using Arduino ADC

I have a problem where I am using TinyGPS library to get NMEA data from a GPS, while also sampling the ADC at the same time. The problem is that it reads the ADC fine, but it seems to execute the GPS ...
1
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2answers
6k views

Use of the GPS 1PPS feature in a system

I'd like to know how synchronization between the GPS unit and any other sensors is done in a typical system. I understand that the 1PPS signal plays an important role. Could anyone give me a very ...
1
vote
1answer
201 views

Can I create paths to two external GPS antennae but use only one

I am making a PCB for a SIM968 GSM/GPS device. Printing PCBs in my country is expensive. I am making this PCB for two different purposes. One is to work in an open environment where there is enough ...
1
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3answers
3k views

Looking for a cheap cellular modem chipset + GPS [closed]

I'm looking for advice about available cellular modem chipsets, my main concerns being power consumption followed reliability & then by weight/size. It can be the worst-performing chipset in the ...
-3
votes
1answer
606 views

GPS is not responding [closed]

I have a skylab skg13bl GPS module. I interfaced it with arduino using the TTL, the status LED is not blinking and the GPS module is returning erroneous data. Here is my code: ...
-1
votes
1answer
71 views

GPS Transmitter Help

I'm starting a project in which I want to be able to attach a GPS module onto a drone in case the drone falls out of sight. I have a few questions as I'm researching parts for this. My ideal specs: ...
1
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2answers
552 views

With regard to GPS signals, what is the significance of I-parts and Q-parts of Complex signal?

What is the significance of I-part & Q-part magnitudes and imbalances in the screenshot? They are listed next to the red Complex signal diagram. Imbalance of I-part: 4.7% Imbalance of Q-part: 25....
-1
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1answer
2k views

Parsing GPS data? [closed]

I wrote a code to simulate receiving NMEA string from my GPS, but faced a problem in parsing the latitude, longitude and date, i want to know what is the problem with the code . here is my code : <...
3
votes
3answers
2k views

What makes this active antenna “active?”

I'm using a external taoglas GPS/Glonass active antenna. It has a male SMA connector and I don't see where any voltage source hooks up to thing. So how is it active? Or does the power required for the ...
-1
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7answers
555 views

Using RFID to secure and prove ownership of a stolen vehicle

Long story short: They stole my bike. This is the fourth one; apparently it doesn't matter how well you secure it, if they want it, they'll take it. Now, the police actually caught them after a ...
3
votes
1answer
950 views

Why does this BGA component have a keep-out layer?

I've pulled the Telit GE864-GPS (datasheet) from the Altium vault. The footprint has a keep-out layer, which prevents me from placing tracks to any pad without using vias. As the pitch is 2.5mm the ...
0
votes
1answer
734 views

GPS SOS Signal Device [closed]

Is there a way to send GPS coordinates from one device to another, without the use of any kind of cell service? What I'm attempting to design is a device that connect to a motorcycles' tip-over ...
4
votes
1answer
2k views

Suggestion for a GPS module with helical/omnidirectional antenna [closed]

I'm looking around for a decent GPS module for a project of mine. The Sparkfun GPS Buying Guide is nice, but focuses mostly on modules with patch antennae. My project is a wrist- or upper-arm-mounted ...
1
vote
1answer
890 views

Duplicate RX in uart (two devices listening one of which is data-logging)

I am not too familial with UART yet, and was wondering if I could some how duplicate the stream of information going to a microcontroller from a GPS. My application will be using a msp430g2553 ...
0
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2answers
239 views

Building a vehicle tracking device

I need to build 100 coach tracking devices. I am a web/mobile programmer, not an engineer, so I'm going to be looking at outsourcing for this. To outsource this work however I should know the ...
2
votes
4answers
1k views

Position tracking system for frisbee

I'm trying to build a smart frisbee for use in Ultimate. I'd like to be able to track the position of the frisbee in a playing field with pretty good accuracy (within ~2ft). GPS is a possibility, but ...
1
vote
1answer
261 views

U-blox 6 GPS module why does it still display points every second when set to 5 minutes?

I'm trying to set up a U-blox 6 GPS module with an Arduino. In order to save power I have tried to reconfigure it using the U center to search for a fix only once every 5 minutes. I have read the ...
1
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0answers
399 views

Shared feed/GND pad on Pulse W3011 antenna

This is my first post; sorry if I've unwittingly broken any rules or accepted conventions around here... I'm using a Pulse Engineering W3011 ceramic GPS antenna. As is common with these small ceramic ...
4
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2answers
1k views

Garmin Gps Battery Modification

I recently bought a GTU 10 from Garmin. I want to extend it's battery life by replacing and soldering on a new battery and enclosing the battery and the GTU 10 in a 1601 Otterbox. I would like to be ...
1
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1answer
176 views

A-GPS, cell tower, and provider service

I am not sure if I used the right forum to ask this question. If it is wrong, please point me the right one. I understand in general how A-GPS works with cell towers, and how it depends on the data ...
3
votes
2answers
4k views

Locate a mobile phone precisely for indoors tracking

Firstly, I don't know if I'm asking this at the right place, so excuse me if it's not. Suppose i want to track a mobile phone in a local area, lets say a large hall of 200 m x 50 m, using any ...
4
votes
5answers
2k views

Trouble in using MT3329 SKM53 GPS module

I bought a SKM53 GPS module a few months ago. I tried hard to make it work but couldn't get anything out of it. I was thinking it's a fault with the device (actually i thought i burned it by not ...
0
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2answers
567 views

Antenna phase shift

My question is regarding RF measurement systems which use antennas signal arrival time as principle of operation e.g. GPS. It is known that impedance of well-matched antenna immersed in lossy ...

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