Questions tagged [gps]

stands for Global Positioning System, a satellite based navigation system

Filter by
Sorted by
Tagged with
0 votes
1 answer
65 views

Noise factor in homemade software-defined GPS receiver

I'm building a homemade software-defined GPS receiver. I'm currently at a point where I can acquire and track strong signals but struggle to even detect weak signals. I've ruled out problems with my ...
user avatar
2 votes
1 answer
34 views

Designing GPS matching network with TESEO and chip antenna

I am new to designing for RF and have a question regarding the design of the matching network for a GPS module I am working on. The datasheet of the chip antenna ANT161575ST-1202A1 recommends a ...
user avatar
0 votes
1 answer
136 views

Why is the Adafruit GPS breakout board no longer receiving after a couple of years?

I attached Adafruit's Ultimate V3 breakout board to my Racpi 3B by using its UART wires. It used to work indoors (I live right under the roof) quite fine for a couple of years when attaching an ...
user avatar
  • 401
1 vote
2 answers
104 views

How do I increase GPS module frequency from 1Hz to 10Hz (beitian gps bn880) library GPS Tiny++

I do a project related to the GPS module I use the GPS module (beitian GPS bn880) connected with Arduino Mega 2560. The module sends data 1Hz so I need speed more but I don't know how to do that. I ...
user avatar
  • 13
0 votes
1 answer
87 views

Why don't the GPS equations account for receiver clock drift?

My basic understanding of GPS is that a network of at least four synchronized satellites send messages containing their locations and transmit times (\$A_i, B_i, C_i\$ and \$t_i\$) to an ...
user avatar
0 votes
1 answer
59 views

At what instant is a GPS receiver position/velocity output valid?

I am just learning about GPS and have been thinking about the timing aspects of GPS receiver navigation output. What is the relation between the time an output is produced and the time that output is ...
user avatar
  • 11
1 vote
3 answers
82 views

GPS PPS out to ADC input

Little bit of background, we are building recording devices that are battery powered and far enough apart that they can't be connected by wire, each device keeps it own time with a GPS receiver and ...
user avatar
  • 113
1 vote
1 answer
75 views

How is a GPS receiver able to calculate SNR?

I know that there is a certain relation between bit error rate and SNR for every modulation scheme. But i wonder how a GPS receiver can measure bit error rate and how it able to calculate SNR (I could ...
user avatar
  • 446
30 votes
2 answers
4k views

How can the GPS position update rate be 10 Hz?

Based on stuff on the web (Wikipedia and others) the GPS navigation message bit rate is 50 bit/s. That includes all data needed for user position calculation (time, ephemeris, almanac, etc.) It seems ...
user avatar
  • 446
1 vote
3 answers
135 views

Time synchronization of circuits in different places

How can i synchronize times of circuits placed quite far(a few hundreds of meters) from each other? I thought of using PPS signal from GPS receivers, but I'm not sure about this point: Are these PPS ...
user avatar
  • 87
0 votes
1 answer
37 views

GPS patch antenna feeding line layout issue

When I tried to put Molex GPS ceramic patch antenna 2042860001 on two-layer PCB, I found it's impossible to connect the feed pin to the RF trace on the two-layer PCB if following the recommended ...
user avatar
  • 482
0 votes
2 answers
110 views

Receive GPS with 2 antennas

For an amateur rocket project, I want to receive the GPS signal from 2 antennas placed in the opposite directions, but I'm very beginner in RF domain. So my first thought is to use a signal Power ...
user avatar
  • 105
1 vote
0 answers
43 views

Is there an advantage to cover all bands of GNSS constellations when selecting an antenna?

I am shopping for shark-style (or aerodynamic low-profile) antennas to make the most of my GNSS receiver (a Septentrio Mosaic X5). Is there any advantage to cover all bands (i.e. ~1.1GHz to 1.6GHz) of ...
user avatar
0 votes
1 answer
47 views

How to Troubleshoot a Garmin GPS 16x HSV?

I'm trying to get one of these guys talking through a rs-232 serial port: https://support.garmin.com/en-US/?partNumber=010-00258-62&tab=manuals There you can download the manual which has all of ...
user avatar
38 votes
4 answers
4k views

How can a 9mm square antenna pick up GPS?

I'm confused again. Per various antenna dipole calculators online, and if GPS uses 1.575 and 1.228 GHz signals, the dipole antenna needs to be on the order of 10 cm. Yet Adafruit has (or had) tiny ...
user avatar
0 votes
1 answer
45 views

Can an auto reset fuse and capacitor save my tracking device from surges while keeping it running?

I work with a few tracking devices and the newest model keeps popping. I've narrowed it down to possible short term current spikes in the trucks they are installed on. The device receives power from ...
user avatar
2 votes
1 answer
74 views

First pin problem

Is this pin first pin of Quectel L76 ? Im confused with this :
user avatar
  • 357
1 vote
1 answer
93 views

How were GPS satellite precisely positioned?

GPS runs off broadcasted signal from precisely positioned satellite. I'm curious, how were these satellite positioned to begin with and what keeps their positions correctly synched?
user avatar
13 votes
1 answer
1k views

How do receivers decode multiple GPS signals on the same carrier frequency?

I'm currently researching GPS signals and am trying to fully understand the path of a signal from satellite to receiver. I understand that mixed into the GPS signal is a C/A code as well as a PRN ...
user avatar
0 votes
1 answer
91 views

Combine two UART inputs to one averaged UART output?

My thought with this project was to combine two UART gps receivers to one board that would then average the GPS position and output a UART GPS signal. I have no idea if this is even possible. I've ...
user avatar
1 vote
2 answers
149 views

4-layer circuit board of GPS module design

I'm designing a 4-layer PCB, containing a GPS module (u-blox NEO M9N) and a Taoglas antenna. The GPS antenna should be on the top layer, and the GPS receiver should be on the bottom layer. Besides the ...
user avatar
1 vote
1 answer
146 views

Battery Considerations For RP2040 and NEO-M9N GPS Logger

I am a software engineer, but new to hardware hacking, so I apologize if this is missing any detail, I will try to be thorough and update with any requested information. I also tried to keep this as ...
user avatar
  • 45
1 vote
2 answers
88 views

RP2040 Board receiving weird output from SparkFun Ublox NEO-M9N GPS Unit

I am a software engineer, but new to hardware hacking, so I apologize if this is missing any detail, I will be thorough. I am working on a small tracking system as a personal project. I am using a ...
user avatar
  • 45
0 votes
0 answers
38 views

Matching circuit for GPS LNA needed?

Do you think I should add Pi matching circuit behind the dipole wire antenna input to achieve the highest LNA gain and low SWR and fine tune it by SimSmith program and NanoVNA ? The route is CPWG 50 ...
user avatar
  • 11
0 votes
2 answers
95 views

Active Antenna with Off The Shelf GPS Module

I'm trying to use an active antenna with the GY-GPSV3-NEO-M8N GPS module. In the hardware manual for NEO-M8N it is said that I need a DC bias circuit like shown in the picture below. As shown I need ...
user avatar
  • 53
0 votes
1 answer
31 views

Connecting Ashtech antenna to mobile device [closed]

Just recently I got my hands on some old GNSS survey equipment from Ashtech, which was originally brought to the market around 2010. It consists of two ASH111660 antennas with corresponding two ...
user avatar
14 votes
4 answers
4k views

How does a GPS antenna have only two connections yet have all this circuitry inside?

This GPS module I have broke (just gets hot and won't work) so I took it apart and am amazed to see all of this circuitry under the ceramic antenna but only two connections (gnd and signal). When ...
user avatar
  • 275
0 votes
2 answers
125 views

Does the Qualcomm MDM 9207 chip have WiFi, Bluetooth and GPS?

I am researching about the Qualcomm MDM9207 chip and I have some questions regarding it: Does this chip contains a WiFi module or do we have to integrate it outside? Does this chip have a Bluetooth ...
user avatar
1 vote
0 answers
144 views

Why is a low resolution ADC (e.g. 4-bits) a bad idea for a Zero-IF GPS/GNSS RF front-end?

This is another follow-up from this fascinating question (the other follow-up question is here) for the design of an RF front-end for a GPS/GNSS SDR receiver. In a comment to the accepted answer, it ...
user avatar
  • 1,454
0 votes
0 answers
69 views

How do I choose IF for a GPS/GNSS RF Front-end?

This is a follow-on from this fascinating question on selecting a TCXO (or entire frequency plan) for a GNSS SDR RF front-end. (I also have another follow-up question here). The MAX2769 and MAX2771 ...
user avatar
  • 1,454
0 votes
2 answers
432 views

What kind of gps battery can I use for uBlox NEO-M8N GPS module?

What kind of gps battery can I use for uBlox NEO-M8N GPS module? Would you please recommend gps battery? and Which can I use 5.5mAh or 11mAh?For example; MS621FE-FL11E - BATTERY LITTIUM 3V 5.5MAH (...
user avatar
0 votes
1 answer
58 views

PCB GNSS module with RPi

I am trying to get a GNSS module to communicate with a raspberry pi serially. I was attempting to set this up with an ESP module but I don't think it will work, or at least I am missing something. In ...
user avatar
-4 votes
3 answers
162 views

Why don't GPS satellites experience power outage more often than they should?

With the advent of smartphones I would believe that there's this huge exponential growth in number of GPS receivers around, and by now there should be an unaccountable number of devices on earth ...
user avatar
  • 1,188
1 vote
3 answers
502 views

How does the 4th satellite in GPS know the time offset?

Going through the working of GPS technology, I came to know that at least 4 satellites must be visible to solve for the location with considerable accuracy. Going through most of the resources, I can ...
user avatar
  • 1,069
0 votes
1 answer
48 views

Arduino : send data via satellite (or other solutions) without GSM [closed]

I'm a researcher. I'm looking to build a very tiny embedded system with low power consumption. I must send data from the desert and above the ocean. To do that I think that my single option is to use ...
user avatar
  • 5
0 votes
1 answer
79 views

What GPS IC do cell phones use [closed]

I am experimenting using gps devices. I managed to utilize a NEO-6M gps module, but it only works when there is a direct 'optical' connection to a satellite (aka it does not work inside a home, under ...
user avatar
1 vote
0 answers
74 views

Connecting RS232 GPS Board to Raspberry Pi

I purchased a NEO-6M GPS board to connect to my Raspberry Pi, and when I bought it I didn't realize that it was meant for RS-232 communication instead of UART TTL (which I believe is what the ...
user avatar
0 votes
1 answer
125 views

AVX M830120 SMD GPS antenna problems - cannot get GPS fix on a prototype board, strange S11 measurements

I’m struggling with AVX M830120 SMD GPS antenna in my project. I have used it in prototype board, did PCB layout more or less according to datasheet, and couldn’t get GPS fix no matter what I tried. I ...
user avatar
  • 71
0 votes
0 answers
54 views

Micro Cat Tracker PCB design

I would appreciate any advice how to improve PCB design to achieve the highest sensitivity for the GPS signal. The design is based on S76G chip. The tracker will be sewn or encapsulated in plastic ...
user avatar
  • 11
2 votes
1 answer
129 views

GNSS module direct grounding to ESP32 increase sensitivity

I have a simple cirquit that composes of the following : ESP32-DevKit-LiPo (ESP32-WROOM) GNSS Module Beitian BN-357P with ufl connector for external antenna GNSS Active Patch Antenna My simple is ...
user avatar
0 votes
0 answers
420 views

GPS patch antenna pcb design

could you please review my layout? It's the top side where the antenna is actually placed. It's bottom side, here I've placed a matching network, LNA (U5)2 and SAW (FL1). The length of the trace ...
user avatar
0 votes
1 answer
31 views

GPS Logger Trigger Circuit Integration

The Arduino UNO and GPS shield logs the coordinates by the use of the trigger inputs. The trigger takes +ve 5 to 15v on a pin. (See Image 1) It is designed to be used to log, each time a solenoid ...
user avatar
4 votes
2 answers
240 views

Homemade GPS Receiver: Cascading LNAs and Band-Pass Filters?

Over the last couple of months, I developed a software-defined GPS receiver. Unfortunately, it's not very sensitive, and can only detect very strong satellite signals. For the RF front-end, I am using ...
user avatar
0 votes
1 answer
341 views

GPS antenna reference design

I have to put a GPS antenna on a PCB layout, but not sure how to calculate a matching network, and how to check that it will work correctly. I've chosen components with desired features (radiation ...
user avatar
0 votes
1 answer
67 views

How do you choose components for a gps antenna

I have to solder an active gps antenna on a pcb. But I don’t know how to choose components. In my case antenna will be used outdoor on a pet collar. First of all there are a lot of different ceramic ...
user avatar
0 votes
0 answers
72 views

Is this circuit correct and will work?

I found this circuit as a gps module on the internet . i look to datasheets and it looks ok. I want to make it for test. is this correct and will work ? Credit: https://www.electroschematics.com/neo-...
user avatar
  • 357
0 votes
0 answers
48 views

Connecting to Venus GPS, checking received UART message, seems garbled

I'm trying to integrate to a Venus VENUS634FLPx GPS chip that I bought through SparkFun many years ago (https://www.sparkfun.com/products/retired/9133). I'm connecting to it through UART and I'm ...
user avatar
  • 335
-3 votes
1 answer
110 views

Can two mobile phones accurately sense the distance between themselves?

This question is inspired from covid19 and current attempts to produce a contact tracing app for a mobile phone. Can two mobile phones accurately (+- 1 m over a range 0-100 meters) sense the distance ...
user avatar
1 vote
0 answers
94 views

GPS PPS Signal Duty Cycle? [duplicate]

just like the title says, I'm trying to figure out the duty cycle of a GPS's Pulse Per Second Signal. This post and accompanying answers seem to indicate something like a 10% duty cycle: GPS PPS ...
user avatar
2 votes
0 answers
43 views

Accurate localization through GPS, IMU and odometry

I am trying to localize a robot with an error <1m. I have XA1110 GPS but haven't tested it in an open area (due to the ongoing disaster) hence I am unaware of its practically achievable accuracy. I ...
user avatar

1
2 3 4 5
9