Airspeed after landing

[echo_sierra]

Hello

I have a D180 with firmware v5.0.
When i power up the D180 everything is fine, airspeed=0.
During flight the airspeed shown by the EFIS is the same as the one shown by my regular airspeed indicator from Winter.
After landing with the aircraft no moving i have my airspeed fluctuating from 25 km/h to 35 km/h on the EFIS and as you can imagine a 0 km/h on the airspeed indicator...
If I turn the EFIS off and then back ON everything goes back to what it is supposed to...
Any idea ?

Thanks for your help...

 

[dynonsupport]

Measuring very small airspeeds reliably can be tricky, and over time you may see effects like this. So, we have a "zero pressure" calibration that you can do to calibrate the zero airspeed pressure measurement that you can do when the air is perfectly still. Go to SETUP > SPDCAL to perform this calibration. Make sure there is NO wind or draft whatsoever - a closed hangar is ideal.