[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Paparazzi-devel] PPZ GPS board and U-Blox LEA-6 - cannot save confi

From: Greg Jones
Subject: Re: [Paparazzi-devel] PPZ GPS board and U-Blox LEA-6 - cannot save configuration
Date: Mon, 5 Dec 2011 12:12:47 +0000

>have you checked if the big capacitor on the board "P11070CT-NDÂ " is functioning normally?



Hi Imed


I measure approx. 2.55 V across that cap and 1 minute after power done it measures 1.2 V.  So the voltage into the V_BCKUP pin of the LEA-6H falls to under 1.4 V within about 45 seconds. According to the U-Blox datasheet this should be between 1.4 V and 3.6 V which is a slightly wider than for the LEA-5H (1.5 – 3.6 V) but the datasheet does mention higher current requirements. Surely this means that the cap is providing nothing other than protection against very brief losses of power? Maybe I have misunderstood something there. Or maybe the LEA-6H does draw significantly more current against the battery backup.


BUT in any case, the configuration should be written to flash memory in the LEA-6H as well as just BBR as it is with the LEA-5H. Since it should be getting written to flash then the BBR is not necessary for holding configuration.


The LEA-6H is reading it’s firmware and configuration from ROM only as can be confirmed by examining the UBlox message UBX>MON>HW2 where we see that the value for “Source of low level configuration” is ROM.


Also I have now since “successfully” flashed the LEA-6H with the new U-Blox firmware 7.03, no errors were reported during the firmware upgrade process which I have repeated a couple of times. But still when power cycled the unit ignores the updated firmware held in flash and boots using the original 6.02 firmware and default configuration which is held in the LEA-6H ROM.


I get the feeling that it is storing both the config and the new firmware in the Flash but that the flash is being ignored at start-up because of the “Safeboot” mode which is forcing the Ublox to read both config and firmware from ROM only.


I suppose this leads to two questions:


1)      Should the U-Blox modules when on a PPZ GPS board be capable of storing configuration in flash (I think they should)

2)      Why is the LEA-6H when on a PPZ GPS board only booting from ROM and ignoring it’s flash memory holding the firmware and config?




reply via email to

[Prev in Thread] Current Thread [Next in Thread]