EVK-M8F-0-01 - User Guide
UBX-15016541 - R01
Early Production Information
Troubleshooting
Page 18 of 21
The EVK-M8F does not preserve the configuration in case of reset
u-blox M8 GNSS technology uses a slightly different concept than most other GNSS receivers do. Settings are
initially stored to volatile memory. In order to save them permanently, sending a second command is required.
This allows testing the new settings and reverting to the old settings by resetting the receiver if the new settings
aren’t good. This provides safety, as it is no longer possible to accidentally program a bad configuration (e.g.
disabling the main communication port).
The EVK-M8F does not work properly when connected with a GNSS simulator
When using an EVK together with a GNSS simulator, please pay attention to proper handling of the EVK. A
GNSS receiver is designed for real-life use, i.e. time is always moving forward. By using a GNSS simulator, the
user can change scenarios, which enables jumping backwards in time. This can have serious side effects on the
performance of GNSS receivers.
The solution is to configure the GPS week rollover to 1200 (as indicated in Figure 7), which corresponds to Jan
2003. Then, issue the Cold Start command before every simulator test to avoid receiver confusion due to the
time jumps.
Figure 7: Configuration instruction for using the EVK with a GNSS simulator
The EVK-M8F receives GPS and GLONASS
Use u-center, version 8.11 or newer. Message UBX-CFG-GNSS allows switching on and off the supported GNSS.
