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GPS Jammers?

A project log for Averaging many GPSes

Average many GPS modules to reduce error

ed0Ed0 05/30/2016 at 05:010 Comments

For the first test I tried attaching 10 GPS modules (9 GY-GPS6MV1, one GY-GPSv3-NEO M8N) using 10 “CP2102 USB 2.0 to UART TTL 6PIN Module Serial Converter” from ebay on BalanceFrom 10 port USB hub.

Everything looked fine at first with the green GPS fix lights turning on one by one on all 10 modules. So, I started a script that opens all serial ports and logs the data, and after a few seconds the GPS fix lights started going out, blinking back on, then mostly being off. Repeating it a few times confirmed that whenever I open the serial port to read data the GPS fix quickly degrades to 2d then no fix. For a sanity check I connected a Teensy 2.0 board using the USB-Serial sketch and everything worked fine. The USB-serial modules seem to be jamming the GPS. Testing more showed that the interference seems to be strongest for the module connected directly to the converter but nearby GPS modules also had some problems.

Testing with ublox u-center shows that the signal strength is very low and it keeps losing the GPS fix.

Since I did buy the CP2102 serial converters on eBay the chips might be counterfeit, or the board may have bad EMI properties. I'd really like to investigate more but I don't have time at the moment.

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