New Heltec e290 DIY Build with XM125 Pulsed Coherent Radar

Not only has the DIY build for Heltec Vision e290 mesh node been simplified, you can now simply plug in the Acconeer XM125 Pulsed Coherent Radar module from Sparkfun and be notified of motion, trigger a relay on motion/presence, and remotely estimate distance and speed of sensed object (fast/med/slow, distance in mm).

As you can see by the components list here, this build is centered around components from Sparkfun.

During the recent trade disruption (tariffs), both the heltec e290 and sparkfun components remained readily available, while certain other options were not (temporarily).

The XM125 allowed us to easily add distance (mm) and estimate speed (fast/med/slow) when sending motion/proximity notifications to your cluster. So, with this particular option, you’ll not only receive the notification that motion was sensed, but also some additional information. If you query the node for “last motion” from any communicator, it will respond with timestamp of last sensed motion/object, along with the estimated distance and speed of the object that was sensed.

As with other ChatterBox functionality, the same asymmetric encryption, digital signatures, and frequency hopping are utilized when this node is communicating with your cluster.

GPS, a Realtime Clock, and Relay can optionally be simply “plugged in” as well.

When you have all the components, the build takes about 30 minutes. See the full build instructions for details.

There is still not a nice 3D printable enclosure for this unit yet, but it is being worked on, so that should be available for download soon.