Inaccurate location from SIM39EA

GPS Modules
#1

As mentioned in the title, we have made a circuit using SIM39EA, and we are able to get the UART Rx/Tx working properly. But we are facing issues with getting a fix. Firstly it takes too long for the chip to get a fix from multiple satellites after a cold start. Datasheet says it should be 35 seconds. In our case it make more than 10-15 mins to get fix. Even after getting a fix, the location reported is more than 500 m away from the actual location. Since this chip is specifically for GPS and multiple people have used it with good results we were are not sure what we are doing incorrectly. Is this something that updating the internal MT3333 firmware can help with, if so can anyone help us with getting the correct latest firmware. Also any other advice to debug/fix would also be appreciated.

Thanks

#2

Forgot to upload the image of our current dev baord with SIM39EA

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@RaviPujar any ideas about it. It was your blog that gave us the idea for using SIM39EA in the first place, and it seems to be a good IC as its used in almost all of your designs.

#3

Its recommended to use atleast 30mmx30mm ground plane or place the module at the edges of the board, but you still got to give it ground plane. There is nothing else in it. And the GPS needs to be outdoors in open sky and no parts should be taller than the module around it.