Question regarding my GPS module

GPS Modules
#1

hi everyone!

I bought a UBLOX NEO 7m module recently and i am planning to integrate it in the vehicle tracker project that i’m working on right now. i tried it in a moving vehicle by connecting it to a laptop just to see how it performs before writing any code. The position it detects is accurate but it takes too long to get a fix and thus between 10-20% of the vehicle’s path is not recorded which is unacceptable for a device who’s sole purpose is to track vehicles :slight_smile:

Now the way i see it there are several ways to tackle this issue:

1: using U-BLOX assist now online service which is a service provided by ublox to their customers , the way it works is that they have many antennae all around the world which track GPS/GLONASS etc satellites live and save their position and other information needed to fix position. You can send HTTP requests to get this info and then save it in your MCU and then push it from the MCU to the GPS module. This will reduce the time needed to get a fix significantly. The problem is that it is only free for 90 days and we have to pay after that and i think it is an expensive service since they haven’t even written a price in their datasheet. Also it requires many hours of trying to understand the syntax of the info they send(it’s in a unique format) and converting them etc.

2: buying an active antenna , but the problem is that a: it changes the minimalist design of my device b: i wanted to ask does it make the PCB design more complicated?

3: use the GSM module’s position tracking ability until GPS gets a fix , this way i can at least have an approximate location before GPS gets a fix. when i try my GSM module’s position detection service , it is off by 50-100 meters which is very inaccurate but it’s better than no approximation at all i guess.

so now i want to ask the good people of these forums , if you were me , which approach would you choose(hint:it is going to be my first PCB design ever so the approach with the least complicated PCB design is preferred)

thank you for reading my wall of text :smiley:

#2

Ok. Something is wrong here. You are using a top class GPS module and its taking too long to fix. On cold start its normal to have a1 to 2 minute to get fix with other modules, but with UBLOX, its very very fast, i have tried it. They are really good modules. So i suspect that you might not have put the right antenna or may be the placement of the whole thing is not right.
Where are you testing it? In urban environment ? How tall are surrounding buildings.?
Even low end Chinese modules get good location once you move out in vehicles. So double check the whole thing, Are you logging the GPS data directly or sending it by some other means?

I haven’t got any need for assisted GPS so far, its only if you design it right.
Wondering what type of antenna are you using?

#3

hmmm today i bought better soldering gear and took off the pins that i had soldered and soldered new ones. This time i had a magnifying glass which improved my soldering. The module seems to be getting a quicker fix i still have to test it in a moving car so im not sure yet but so far it seems like poor soldering was at least one of the reasons for my problem.

p.s : i never thought that poor connection could lead to poor GPS performance , i mean my antenna connection was ok the problem was the connection between the pins(vcc,grnd,tx,rx) and the PCB’s tracks. Now i understand why designing the traces on PCBs is so important :smiley: