EVK-M8U - User Guide
UBX-15023994 - R01
Advance Information
Troubleshooting
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about 50 dBHz. With a standard off-the-shelf active antenna, 47 dBHz should easily be achieved. Low C/No
values lead to a prolonged startup time.
The EVK-M8U 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-M8U does not work properly when connected with a GNSS simulator
When using an EVK together with a GNSS simulator, 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 4), which corresponds to Jan 2003.
Then issue the Cold Start command before every simulator test to avoid receiver confusion due to time jumps
.
Figure 14: Configuration instruction for using the EVK with a GNSS simulator
Power Save Mode and USB
For communication in Power Save Mode, use the RS232.
EVK-M8U receives GPS and GLONASS
Use u-center v8.22 or newer. Message UBX-CFG-GNSS allows switching on and off the supported GNSS.
