USB-C Powered Mesh Node

Platform: Heltec LoRa Series (Wireless Stick Lite V3 / ESP32-S3)

Overview

A durable, weather-resistant LoRa mesh node built inside a round metallic electrical junction box. Powered externally via a panel-mount USB-C pass-through connector installed directly into a bottom screw-in cover, this node combines continuous USB power with an internal Li-ion backup battery, a 3D-printed board mount, an inline power switch, and a side-mounted right-angle Muzi whip antenna for flexible deployment.

Bill of Materials (BOM)

Category / Item	Quantity / Packaging	Link / Supplier
Enclosure: Round Metallic Weatherproof Junction Box	1 Unit	Amazon
Microcontroller / RF: Heltec Wireless Stick Lite V3	1 Unit	Heltec
3D Printed Mount: Heltec Wireless Stick Lite Holder	1 Print	Printables (#837546)
Antenna: Muzi 915MHz SMA Whip Antenna	1 Unit	Amazon
RF Hardware: Right-Angle SMA Male to Female Adapter	1 Unit	Amazon
Power Input Port: Waterproof USB-C Panel Mount Connector	1 Unit	Amazon
Backup Battery: 3000mAh Single-Cell Li-Ion Battery	1 Cell	Amazon

Initial internal fitment showing Heltec board, battery, and SMA ground connection inside round metal enclosure

Figure 1: Initial layout and component fitment inside the round metal chassis, showing battery placement and RF ground point. (Click image to enlarge)

Build & Assembly Steps

Step 1: Enclosure Drilling & Screw-In Cover Modifications

Instead of drilling directly into the main cast body of the junction box, drill out the removable screw-in port covers:

Drill the side screw-in cover to accept the SMA female bulkhead pigtail.
Drill the bottom screw-in cover to mount the waterproof USB-C panel-mount bulkhead connector.

Step 2: 3D Board Mount & Component Fitment

3D print the snap-in board holder (Printables #837546) for the Heltec Wireless Stick Lite V3.

Mount the Heltec board into the printed bracket and secure the bracket centrally inside the junction box using adhesive or mounting screws. Tuck the 3000mAh Li-ion battery securely along the inner wall.

Thread the drilled side screw-in cover back into the enclosure port with the SMA bulkhead mounted and properly grounded to the chassis, then attach the U.FL/IPEX pigtail to the Heltec board's IPEX connector.

Step 3: USB-C Pass-Through & Power Switch Wiring

Install the waterproof USB-C panel-mount jack into the drilled bottom screw-in cover and thread the cover back onto the bottom port.

Route the internal USB-C cable directly into the Heltec board's USB-C port to provide main 5V power and full serial connectivity. Wire an inline power switch into the positive battery lead and position it near the top cavity for easy access during maintenance.

Fully wired interior showing USB-C cable routing, power switch, battery, and side-mounted antenna connector

Figure 2: Completed interior wiring with USB-C pass-through cable connected, inline switch installed, and side antenna adapter attached. (Click image to enlarge)

Step 4: Antenna Attachment & Field Deployment

Thread the right-angle SMA adapter onto the external side bulkhead so the antenna points vertically.

RF SAFETY PRECAUTION: Always ensure the Muzi 915MHz whip antenna is securely attached to the SMA adapter before turning on the power switch or connecting USB-C power to prevent damaging the SX1262 power amplifier.

Connect an external USB-C power cable to test operation, align the round cover plate gasket, and tighten the cover screws to seal the build.