Build your solar powered LoRa DiGi, router, repeater...

LoRa mesh networks are increasingly popular today. Thanks to their long range, low power consumption, and strong developer support, a wide variety of LoRa-based networks can be found in operation—such as Meshtastic, Meshcore, LoRa APRS, Meshcom, and others.

This board is designed for off-grid deployment, solar-powered operation, and installation in remote locations. With an integrated MPPT solar charger, it can efficiently harvest energy even from small solar panels or under low-light conditions.

The system supports up to four 18650 batteries. Battery longevity is enhanced by an automatic disconnect function when the cells are deeply discharged. This protection is temperature-dependent—the lower the battery temperature, the higher the cut-off voltage.

An additional protection feature allows charging to be disabled when the battery temperature drops below freezing. With the HT MeshGate LITE board version, it is also possible to redirect energy from the solar panel to battery heating.

The core of the LoRa system is a module from RAK Wireless, specifically the RAK4630, which supports frequency bands of 433, 868, or 915 MHz.

An additional feature is CPU monitoring via a hardware watchdog. This circuit requires a pulse at intervals shorter than 60 seconds; otherwise, it triggers a system reset. Support for this function must be implemented in the device firmware—for example, in Meshtastic, this is handled by the Heartbeat function.

The board also integrates a BME280 sensor, which provides temperature, humidity, and pressure measurements.

For further details, refer to the block diagram.

MeshGate LITE board HERE.

Outdoor enclosure:

Solar panels are an important part of the off-grid system. The panel allows you to connect to various MPPT voltage ranges. Two options are preset: 5 and 18 V. Another option is a custom voltage, which is set by adding resistors.

You can find more here.

Well, given the low RF power but the need for long-range coverage, the antenna is a key component. For key locations, I recommend collinear antenna systems with multiple elements.  See more HERE.

In built-up areas and locations with strong LTE and GSM coverage, interference can become a significant issue. This is due to the close proximity of these frequency bands to those used by LoRa, which can reduce the sensitivity and overall range of IoT devices.

A band-pass filter can significantly improve performance. However, commonly used SAW filters typically have a relatively wide passband. While they do attenuate some interference, they can also degrade the receiver’s noise figure.

From this perspective, a cavity filter is a more effective solution. It provides superior selectivity and minimizes unwanted signals without significantly impacting the noise figure. The main drawback is its complexity and cost, as it often features a precision design with a silver-plated interior.

See more HERE.