The GPS chipset used in the Bad Elf GPS (BE-GPS-2300) is affected by a GPS rollover bug that started on October 30th, 2022.  Every Bad Elf GPS Pro+ running firmware older than 3.0.0 is affected. This issue is limited solely to the Bad Elf GPS Pro+, and does not affect any other Bad Elf GNSS receivers.


This bug in the GNSS engine caused 3 problems:

  1. Incorrect GPS date (reverting back to March 2003)
  2. Loss of GLONASS functionality (due to low-level algorithm dependency on #1 above)
  3. Corrupt NMEA RMC sentence (including speed/track/elevation fields), affecting some iOS and Android apps

As of 09-DEC-2022, these issues have been fully resolved via a 2-part firmware update. Follow the instructions at the link below to install the updates on your Pro+ using your PC or Mac:

Bad Elf Pro+: Updating the Pro+ firmware via USB


The date associated with the positional data provided by the Bad Elf GPS Pro+ will reflect a moment in the distant past 19.6 years prior to reality.  This behavior is most notable with the data logging feature of the Elf, but is also present in real-time data.  

If your Pro+ has logs showing year 2003, DO NOT DELETE THEM FROM YOUR PRO+.  The firmware update above will fix them, but can only do so if the logs are still present on your Pro+

Data logs stored on the Elf

Data logs after transferred to the Bad Elf App

GPRMC NMEA message

For any further assistance, please contact our support team via