Gauge keeps switching between AFR and Lambda

[blaze falconburger]

I did have the gauge set up to display AFR top row, revs bottom row.  This worked fine (except the revs intermittently dropping out, see my other post on that one), using firmware 2008-02.

Today I decided to upgrade to the latest firmware to 2009-04-30, well that didn't boot, so I reverted to 2008-02.  I am using a different laptop to what I used before, so lost anything that had been changed in MegaTune, so started with the defaults.  I set the gauge to display AFR & revs, saved it to the ecu, it did display for quite a few minutes - until I started driving.  Then it started switching between AFR & lambda every few seconds.  What on earth is making it do this?!

[rob@vems.co.uk]

Have you got anything connected to the analogue in?  If so you need to put a resistor in line.

[blaze falconburger]

Hi Rob, yes I have the signal from the map sensor on analog in, along with a resistor, I think I used a 180ohm.  Does this need to be greater?  What makes it switch just because of a connection on analog in?

[rob@vems.co.uk]

I would go with something over 1K - maybe upto 10K
The button uses the same analogue channel as the analogue input, if you are logging the channel - press the button and see what happens!
There is a setting in MegaTune for the button threshold/switch voltage, I can't remember for the life of me where it is though.

[blaze falconburger]

Ah that would explain why it was fine on idle and only started happening when driving! Though I'm sure the button didn't do anything when pressed.  I tried to use a low resistor to not affect the map sensor input too much, I'll change to a higher value resistor and see if it solves it.  Luckily I hadn't worked out my calculation to use the map sensor yet! Thanks for the help