Garmin on indoor trainer

StrathRC

I'm trying to promote cycling at a sports fair tomorrow and am hoping to setup a bike on a turbo trainer to let people compete over 500m times (like rollapaluza).
Does anyone know how to get readings for distance and speed on a garmin (edge 800) on an indoor trainer??
These fields both stay blank whenever I try.
I have tried switching GPS off
I have noticed that my garmin might not be picking up the speed/cadence sensor but I don't know how to fix this.
Many Thanks

amaferanga

Have you paired the speed/cadence sensor? If so then have you selected it as being 'present'?

mattshrops

Theres a little reset button on the speed cadence sensor which you might need to press with a pen nib.
The sensor may need a new battery(and then press reset)
Check that the two lights come on -one green one red- when you spin the wheel and cranks.
Make sure both sensors are close enough to the speed /cadence sensor.
Not necessarily in that order

OH btw thats for a 705 hopefully same for 800.

dw300

Might need to set your wheel circumference manually if it's set to auto if the above don't work.