I recently got a new Edge 810 and was paring the sensors - Power Meter, HR Monitor, Phone all without issue. I have a speed sensor that I use when riding on the trainer but I could not get the Edge to recognize it. The Speed Sensor is about a year old so I thought it could be the battery. Replaced the battery and the indicator light flashed green - red - green to indicate it was activated. I attached it to the hub and when I rotated the wheel to see if the sensor was transmitting the green indicator light never flashed and the Edge never recognized it. Repeated the process but still no dice.
The installation process couldn't be simpler but if I'm missing something please enlighten me

"Couldn't get it to recognize"...do you mean that when you go to Sensors>Speed it doesn't show up at all...or that it shows up and pairs but doesn't give a reading?

I go to sensors it comes up speed/cadence I switch on enable then search and it tells me speed/cadence sensor not found.

I just realized that I most likely posted this in the wrong forum. Should have been in electronics so apoligies for that.

Wait a second...are you using the new accelerometer sensor(s)? Or the old GSC-10 speed/cadence sensor?

If you're using the new accelerometer sensor, you must search for a "speed" sensor to pair...searching for a "speed/cadence" sensor when you only have the accelerometer sensor is a path to unhappiness.

We have a winner! Where I was going wrong was when I tapped on the speed and cadence icon it opened as speed and cadence sensor on the screen I didn't realize that if you tapped on that it would drop down for more options. In any event when I went to speed sensor it synced. All's well.
Thanks for saving me from myself.