MeshCore repeater

MeshCore repeater

MeshCore solar repeater based on the Heltec T114 LoRa module.
Completed Electronics Radio

I built this solar-powered repeater for the MeshCore network.

Components

List of components used:

  • Radio module: Heltec T114
  • Antenna: TX868-BLG-26 3dBi
  • MPPT: CN3791 6V
  • Batteries: Li-Ion 18650
  • BMS: BMS 1S 3.7V 3A
  • Solar panel: 17.4 cm x 12 cm
  • Sensor: BME280
  • RTC: DS3231
  • Timer: C005
  • Cable gland: PG7
  • Vent: M6x1.0-7
  • Enclosure: HS101570 IP67 (150x100x70 mm)

Details

MeshCore repeater.
MeshCore repeater.

The components are secured to the removable base of the enclosure with cable ties, and the battery holders are glued to the enclosure lid.

Components.
Components.

Antenna

The antenna is made of fiberglass, with 3 dBi gain, and has an N-type connector sealed with silicone tape.

Antenna.
Antenna.

Radio module

The radio module used is a Heltec T114 based on the nRF52840 and SX1262.

LoRa radio module Heltec T114.
LoRa radio module Heltec T114.

Sensors

A DS3231 RTC clock and a BME280 environmental sensor, which measures temperature, humidity, and atmospheric pressure, have been connected via I2C. This data can be read by the repeater’s telemetry system via the MeshCore network.

RTC and environmental sensor.
RTC and environmental sensor.

Solar charging

Battery charging via the solar panel is managed by an MPPT CN3791.

MPPT.
MPPT.

Autoreset

An autoreset module is included that resets the Heltec T114 module via the reset pin approximately every three days. This resolves potential MeshCore firmware lock-ups if the repeater is installed in a location that is not easily accessible.

Autoreset system source: Lora Italia .

Autoreset timer.
Autoreset timer.

Batteries

The system is powered by four 18650 lithium cells in parallel, protected by a BMS. The total battery capacity is approximately 4800 mAh.

18650 cells and BMS.
18650 cells and BMS.

Solar panel

The solar panel is mounted on the lid of the enclosure and positioned vertically to provide better protection against hail and dirt, although this results in lower power output.

A 3D-printed protective cover is mounted above the solar panel.

Solar panel protection.
Solar panel protection.

The solar panel is attached to the enclosure by a screw sealed with a 3D-printed TPU gasket.

Enclosure lid and solar panel mounting.
Enclosure lid and solar panel mounting.

Enclosure

At the bottom of the enclosure, there is a cable gland for the solar panel cable and a vent plug to equalize the internal and external atmospheric pressure as the temperature changes, while limiting moisture ingress.

Cable gland and vent.
Cable gland and vent.

The enclosure is closed with metal clips.

Box closure.
Box closure.

The 3D-printed MeshCore logo is located on the side of the enclosure.

MeshCore logo.
MeshCore logo.

Mounting holes are located on the back of the enclosure.

Enclosure dimensions.
Enclosure dimensions.

MeshCore repeater.
MeshCore repeater.

Wiring diagram

Wiring diagram.
Wiring diagram.

Heltec T114 pinout.
Pinout Heltec T114 pinout.



License

Author: Mazzo.me

Link: https://www.mazzo.me/en/projects/meshcore-repeater/

License: CC BY-NC-SA 4.0

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Please attribute the source, use non-commercially, and maintain the same license.