Questions tagged [gps]
stands for Global Positioning System, a satellite based navigation system
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What is the actual physics and reasoning for the “Ground plane” underneath a GPS patch antenna
From my very limited knowledge of EM, I believed that anything tied to earth can absorb radio waves, so if an antenna was to be placed above a ground plane, why does the ground plane not just absorb ...
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Ferrite Bead for Ublox M10S GPS unit
I am trying to understand what ferrite bead to use for the Ublox M10S GPS unit. I am using as a reference the design from SparkFun GNSS Receiver Breakout - MAX-M10S (Qwiic) (https://www.sparkfun.com/...
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Powering a pico with a lipo battery charged by a bike dynamo
So, I am building a gps tracker build on raspberry pico and a neo 6m gps module. Now, I want to power this project with a lithium battery that can offer some autonomy. I was thinking of using a ...
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Switch Mode Power Supply / GPS - Filtering+Shielding
I'm working on my first RF PCB, for GPS/ GNSS and am particularly concerned about Noise/ Interference. Hopefully someone can shed some light, or point me toward a similar thread?
It's worth noting ...
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Can you do without a base station for RTK GPS if only relative positioning is needed?
I am trying to take two drones in an open field and have them know precise and accurate relative positioning of each other. I don't need them to actually know where they are. My plan is to use some ...
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Raspberry Pi Pico powered by a bike dynamo
I am building a GPS tracker for my bike using a Raspberry Pi Pico and a NEO-6M GPS module.
I need this GPS to be up and running at least 14 hours a day.
The only problem is the power source. Ideally ...
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GPS signal combiner
I want to use WP4N+ as a GPS signal combiner with NEO 6M receiver. Here is my schematic.
On power on, resistor 22 Ω is getting VERY VERY HOT and I do not receive any signal from the satellites. ...
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Why am I getting incomplete geolocation data for long periods of time using SIM7070g?
I'm facing a problem while working on a tracking application using the SIM7070G module for GNSS data. The application alternates between sending data and retrieving GNSS coordinates due to SIM7070G ...
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Can I improve the GPS accuracy by choosing a different antenna?
I am currently looking for an antenna to determine GPS location.
The question is a general one, but I have listed the equipment that I am using to help ensure that answers are more likely to be ...
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GPS 4-layer stackup
I'm developing a GPS module with passive ceramic patch antenna, I need suggestions if the following 4-layer stackup I've chosen might work:
Top layer has the ceramic patch antenna and a status LED,
...
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How transmit and receive work from the same antenna and pin for RFD900?
I'm currently using the RFD900 SMD version for an avionics bay for long range GPS capabilities. I have read the datasheet and saw this:
The RDF900ux(-SMT)/868ux(-SMT) modem has two antenna ports and ...
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Receiving Timestamps from PPS using uBLOX MAX M8C-0 GPS Receiver
I am having problems with sending and receiving the messages. I am using the SDA and SCL lines. My goal it to try to use the PPS to get under 5 millisecond accuracy for timestamp purposes. Could ...
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Best way to close GPSDO PLL digital loop?
I am trying to build a GPSDO with a holdover capability of 500us/24hs (maximum drift accumulated).
The system uses a 10MHz OCXO and it is my intention to use a microcontroller (ATMega, STM or ...
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GPS UART NMEA output to iPhone
Working on a tracker project. Idea is this:
L80-M39 GPS (UART) -> RF Transceiver <--- distance ---> RF Transceiver (UART) -> ?
On the right-hand side, I am getting location information via ...
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GPS/GNSS standard active antenna voltage and current draw
I'm designing a GNSS receiver that I'd like to be compatible with a variety of different active antennas. What antenna voltages are possible, and is there any (unofficial) standardization of this? I'...
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Do all u-blox ZED-F9T input pins have internal pull-up resistors?
The ZED-F9T datasheet says in section 5 Communications Interfaces:
All the inputs have internal pull-up resistors in normal operation and can be left open if not used.
This statement on its own ...
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What's the purpose of VCC_RF for u-blox ZED-F9T GNSS receiver?
The ZED-F9T, and presumably other u-blox GNSS receivers, can power an active antenna with a VCC_RF pin. The VCC_RF voltage is specified as being essentially the same as the module voltage (VCC) (...
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SIM808 module does not get GPS location
I am trying to use a SIM808 module to get a GPS location, but it does not work. My power supply can provide up to 5A. The picture results from my communication with the SIM module using the AT command....
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Ublox Neo M8N + wemos lolin32 serial monitor problem
So i have a neo m8n that should print my lat and lon to the serial monitor,but fails to do so. Here is the code:
...
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Can the PA1616D GPS module connect to a backend server to send GPS updates to a mobile phone?
I am building an IOT device that will be moving around outdoors and will not be able to have a secure wifi connection. I want to be able to know the location of this device at all times on my mobile ...
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How to set the output frequency for the PPS pin on the CD-PA1616S GPS module? (Used in Adafruit Ultimate GPS board)
The datasheet says you can change the freqnecy...
1.5 1PPS
A pulse per second (1 PPS) is an electrical signal which precisely indicates the start of a second with the accuracy of ±20ns RMS (Root Mean ...
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Why are there LC filters on the UART line to the M20050-1 GPS module?
I am designing an IoT device.
In first version, I forgot to put the LC filters as in the datasheet.
I found it after I get the prototyping board on my hands, but I thought it would be fine without ...
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Why is civilian GPS symmetrically encoded?
Why is civilian GPS information symmetrically encoded? It is encoded using symmetric MAC, with the MAC key also being broadcast. This seems completely pointless. Why don't they use private/public key ...
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Pin assignment of L86 GPS module
I have a gps module called quectel L86-m33. However I couldn't understand which pin is first one(rx in this case) and which one is ground. I think large size pad is ground but I need a correction.
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What's the deal with different size GPS antennas?
I have some GPS modules laying around and I noticed they're pretty different size to each other.
(here are two of them for example):
So doesn't any antenna have to be a specific size for a given ...
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Confusing antenna datasheet (feed points)
I'm looking at the TDK ANT016008LCD1575MA1 for a GPS application. It has two pads for radiator electrodes (which is for tuning/matching capacitors).
But it's confusing about the four feed points. It ...
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What attenuator to use for using HackRF one to simulate GPS for in production testing?
I am trying to use the HackRF One to simulate GPS to test devices in a production environment. I am currently able to get the GPS signal on my GPS receiver that I am testing, but the signal is much ...
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NEO-M8N Microstrip Line Calculator
I am designing a pcb which has the module ublox NEO-M8N, However I am having trouble calculating trace widths. I am planning to use an FR-4 board. I was using the following calculator to try and ...
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USB 3.0 noise blocking GPS signals
We have designed a compact system that has:
Custom processing unit with USB phy and a USB 3.0 HUB (usb5744) with custom plastic USB connector.
USB 2.0 wifi module(external peripheral connected with ...
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What are this components on uBlox EVA M8M GPS?
I am designing my own pcb board based on a Sodaq One V3 (I built my prototype with a Sodaq One V3 and a MAX30102) and I am currently integrating both devices in KiCAD but I have a doubt with the GPS ...
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How can a GPS receiver estimate position faster than the worst case 12.5 min it takes to get ionospheric model parameters?
Consider a single-frequency GPS receiver. On the legacy L1 C/A signal, the receiver will over the course of an entire navigation message (12.5 min) get the model parameters for the ionospehric ...
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Could multiple transmitters on the same frequency work if phase-locked to GPS? (gedanken)
I've been noodling this concept for a while; it seems to me that if it were actually workable somebody would be doing it already, but I haven't heard of it happening. So where do I go off the rails ...
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GPS Active vs Passive SMD antenna
I'm designing a tiny wearable device that is characterized by a plastic case. It contains the PCB and the battery (Lipo).
I'm struggling a lot with the GPS antenna because I must use a small SMD ...
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Problem with GPS old location [closed]
I wrote a GPS driver which sends and reads AT commands. I send the AT+CGPS=1,1 command to get the GPS location and if there is no answer I send ...
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GPS pulse/s not aligned with reported times (u-blox ZOE-M8Q)
For the sake of fun and learning, I'm trying to make the most accurate wall clock I possibly can, driven by GPS. I'm starting with a u-blox ZOE-M8Q breakout board I got from SparkFun, and a Raspberry ...
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Sharing multiband antenna between ICs
I am working on a ultra low power project where portability and low weight is important. The circuit would have multiple ICs, that need to communicate over multiple frequencies:
Esp32 - WiFi/Bt 2.4 ...
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Mediatek MT3333AV doesn't start
Recently I started a project with an MT3333AV GPS IC. I desoldered the chip from the L86 GPS module and put it into my project.
After many tries I still can't start the IC. There is no 1.1 V going ...
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Reverse trilateration / multi-lateration using BLE Beacons
I'm currently working on a proof-of-concept to work out the estimated locations (longitude and latitude) of outdoor beacons with unknown locations to begin with.
The solution will use a mobile ...
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Why do some GPS modules in smartphones have two or more antennas?
Some GPS modules have only one antenna, but some of them have two and more. For what? Are they made for different frequencies and ranges?
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How to detect if a user has gone past certain locational boundaries physically [closed]
I want to write some software that takes the location of a user's phone and makes sure it is within a certain boundary that is set by "invisible fences"; see the picture below.
What kind of ...
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Do I need via shielding for the GPS antenna trace?
I'm working on a 4 layer board (signal, GND, PWR, signal). I have a NEO-M8P GPS module and the Hardware integration manual says to connect the antenna with a 50 ohms impedance trace to the connector ...
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Do I need a GPS simulator to design a device that contains a GPS receiver and a pre-designed antenna?
I have designed a device using an STM32 Nucleo board, a GPS module, a GSM module, some discrete components, and a bread board. It is a sort of a car tracker.
I have decided to design my own custom ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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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 ...
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