Tech Friday: Ultrasound detection and the 4th gen Echo hub

Posted By on June 24, 2022

After a week of working with the new “trade-up” from an older Echo (triggered by a $30 trade-in offer) to the 4th generation Amazon Echo “with premium sound, smart home hub (Zigbee) and Alexa … the results have been mixed. My advice, don’t rush.

First, I was looking forward to the idea to not need another “cluster of wired devices” (a separate hub) to handle Zigbee sensors that I’ve been planning to add (motion, water, etc) … so going with the all-in-one Echo smart Echo4thGenHub220623speaker made sense.


Second, I thought perhaps since this new 4th generation device also has “ultrasound motion sensing” that I might be able to forgo adding additional motion sensors? Unfortunately after hours of back and forth with very helpful and patient Amazon support folks (thank you Vanessa), the routines I was attempting to program using “only” the Echo are not going to work. For those who have used “motion sensors” in the past, it all as to do with what is referred to as the “cool-down” period. In the 4th gen Echo hub’s case, thirdrealitymotionsensor_sthere was no way to reduce it to less than 30 minutes in order to reactive a routine again – ie. detect activity to turn lights on (most motion sensors are under 1 or 2 minutes). For the record, I could have just left the lights on for 30+ minutes and then after the “cool-down” triggered them to come back on again with continued activity or remain off if there was no presence detected.

So to solve my particular situation (stair lights), I opted for a motion sensor from ThirdReality to solve the problem … and it could be located exactly where detection is needed. A more perfect solution would have been a fully 110AC “socket” powered Zigbee motion sensor … but they must not exist (leave a comment or send me a message if they do exist?)

The final disappointment is the Echo’s Zigbee hub range. I wanted to put this new 4th gen Echo in my soon to be finished second floor home office, but the distance is too far from the basement … which is where the future sump pump water detection sensors and the current basement stairs motion sensor is. So for now, it will improve the music quality in the workshop. 😉


Desultory - des-uhl-tawr-ee, -tohr-ee

  1. lacking in consistency, constancy, or visible order, disconnected; fitful: desultory conversation.
  2. digressing from or unconnected with the main subject; random: a desultory remark.
My Desultory Blog