EEPROM write voltage spike on MEGA, causes baro alt spike?

[rubadub]

Can anyone with a MEGA board & MS5611 please try the following test:

• power up board
• connect to MW GUI
• make sure that the altitude readings from the baro sensor have stabilized in the graph
• make any change (such as an AUX checkbox) and write the changes to EEPROM
- the readings will appear to pause for about half a second as the EEPROM write takes place.
• observe if the altitude readings on the graph experience a noticeable shift after the EEPROM write completes.

- On my CRIUS AIOP V2 boards, there is a spike of almost a meter, and then a small dip before the altitude readings stabilize once again.

I'm trying to determine if this is a programming defect/side-effect, or if there's actually a voltage drop/spike on the board due to the EEPROM write that causes a glitch in the MS5611 BARO sensor readings. Please help, I'd really appreciate it.

[brewski]

I set up my quad (with Crius AIOP V2) as you detailed & yes got approx. a metre increase in altitude in MWConfig. In MW WinGUI it was not noticeable as I haven't been able to work out how to change scaling.
Come to think of it I had noticed a change in altitude when writing to EEProm using EZ-GUI whilst hovering. I just assumed that there was an cycle freeze when writing.
I suspect the 3.3V regulator is dropping voltage during writing so perhaps a 100uF 6V cap on reg output would sort this.