Hi all,
As expected i had the GPS issue with my recently purchased mini 903 dash cam...
I desided to have a look about how i can improve things.
After about 2 hours i can say that the problems are solved for me, i cannot say that the problem is 100% elliminated because i checked the gps satellites signal on my mobile with the nanoq on/off and there is still some signal decrease with the nanoq on but it seems that i have no issue at all.
No issue i mean that from the >5 minutes that the gps needed to lock, now it seems to be almost instant, just a few seconds.
As i have prepared about 15 photos let me say what i tried to do.
The issue was affecting the gps receiver (base) of the unit.
So the targets was two:
1) To reduce the interference emmited from the camera unit.
2) Reduce the interference reaching the GPS unit.
ΠΡΟΣΟΧΗ!!
I should warn you that i am not responsible if you try or if you attempt to do the below and destroy things, you car or yourself....
After i oppened the unit i realized that the plastic casing was already coated with copper based conductive paint.
Inittialy that made me thing that the "EMI 35 Electromagnetic Shielding - Spray that i ordered will probably not be needed.
As you can see the copperish spray is indeed conductive.
You will see that there are in total two elastic foam things with square cross section and condactive external braid that are used to electrically connect the "ground" of the two PCB's (printed circuit boards) with the conductive paint of the plastic casing.
To my liking it didn't seem that the below was making a good contact so i helped it with an elastic piece that i used capton tape to hold it in place on the top of one of the big capacitors.
I used 1cm copper tape on top of the existing copper paint in order to better "shield" the internal of the camera case, in the photo below you can see covered half of the cover side that is close to the copper tape roll.
In the photo below you can see the completed back cover of the camera.
I should note that the back of the display was already covered with a different type of shielding like a silver metallic cloth. Nevertheless i covered this as well with the copper tape.
Be carefull to cover it carefully with capton tape in order to insulate it, we don't want the copper taped parts to make electrical contact with the components on the PCB.
One of the important things that i noticed even before i had the camera completelly oppened was that this conductive foamy thing was NOT electrically conductive with the camera ground, that is for example the micro usb external side that is also soldered on the pcb. The soldering points are the two round holes between the micro usb connector and the "foamy" thing. That f thing is sticked in place with a sticky paper -as you can see in the picture below- but that sticky parer does not permit the electical contact.
That means that the back comera cover was not really using properly the internal shielding coating.
We don't want the foamy thing to make contact with any other pin on the PCB and also it should not move arround as it will mess up the camera.
So, i put some capton tape to insulate the nearby pcb parts.
I cannot post more pictures so i will continue on the next post.