Hardware

A short, opinionated guide. Keep in mind that node performance depends on many factors. Board selection is only one part of the equation; power management and antenna quality are often even more important to overall performance and reliability.

Selecting the Right SoC (System-on-Chip)

There are currently two common SoCs used in mesh networking devices: the nRF52840 and the ESP32. Selecting the right SoC for your application is important, as it will significantly impact battery life, device capabilities, and overall user experience.

NRF52840 (Recommended for Most Applications)
The Nordic nRF52840 is generally the preferred choice for battery-operated handhelds, repeaters, and router applications due to its excellent power efficiency and robust Bluetooth performance. Devices using the nRF52840 can often last 5–10 times longer than a comparable ESP32-based device using the same battery capacity, making them ideal for solar-powered nodes and simple companion devices. Power efficiency makes a major difference in real-world use. An nRF52840 device may run for days or even weeks in applications where a similar ESP32 device might only last a single day on the same battery. This can make or break a solar-powered installation.
The trade-offs are that nRF52840 devices typically cost slightly more, have a slower CPU, less RAM, and do not support Wi-Fi connectivity.

ESP32 (Only Recommended for Special Applications)
The Espressif ESP32 offers substantially more processing power and RAM, making it better suited for standalone handheld devices with large displays, multiple inputs or sensors, room servers, and MQTT gateways. The ESP32 is used in many popular standalone handhelds, including the LILYGO T-Deck.
The trade-off is significantly higher power consumption and shorter battery operating times. Fixed solar installations using ESP32 devices generally require larger batteries and solar panels to maintain reliable operation.

What to Look For When Buying Devices
There are a lot of manufactures out there using both of these SoCs, ensure that the SoC is specified in the sales listing to ensure you are getting the performance you are expecting. Devices are often sold as development boards and require the buyer to self source cases and power management, be sure to read through listings carefully as it is common to require additional parts to finish a device.

Companion Devices (Handheld / Portable)

Battery-powered devices intended to be carried by users.
These devices generally fall into three categories:
Headless:
No built-in interface; requires a phone or tablet
Basic:
Small display and simple button interface; still designed to work alongside a phone or tablet
Standalone:
Full display and user interface; can be used independently without a phone or tablet

Pricing varies — check the supplier links below. Heltec V3 is typically the cheapest; the modular RAK Wisblock and the T1000 / RAK tag sit at the higher end.

Repeater Devices (Support Infrastructure)

Solar-powered or battery-backed infrastructure nodes placed strategically to support companion devices and extend network coverage. Mains power can be used when available, but battery backup is strongly recommended.
Because repeaters are often exposed to the elements for long periods, proper weatherproofing is important. Add drip loops to cable connections. LMR-240 or better feedline; keep it short — coax loss eats antenna gain quickly at 915 MHz. Antenna quality matters much more for repeaters as they form the backbone of the network. If possible, antennas and cables should be tested with a VNA to verify performance.
Antennas in the 3–5 dBi range are common because they provide good local coverage. Higher-gain or directional antennas can be used for long-distance links, but may reduce nearby coverage and are not ideal for general-purpose repeaters. It is strongly recommended to use boards with NRF52840 SoCs for any solar application
Placement and elevation are the bedrock of how successful a repeater is, please take a look at Repeater operators before deploying.

These devices are available pre-assembled, as kits, or can be scratch-built using development boards. Some boards include built-in solar charging and battery management features, while others do not, so be sure to review the documentation for your specific application.
Low-cost MPPT solar charge controllers and single-cell battery protection (BMS) boards are widely available, and battery protection is always recommended.
Lithium-ion batteries can still be used in cold Canadian winters when node power consumption is kept very low. For more information on cold-weather lithium-ion use in mesh applications, see https://yycmesh.com/blog/cold-weather-charging.

See Some Hardware Options Below

MQTT Gateways and Room Servers (Powered Fixed Installation)

ESP32 devices make sense in this application as gateways require internet access and room servers require storage and additional processing power. Pick a device from the companion list that is ESP32 capable, and it should be suitable to this application.

Boards to Avoid

Heltec V4 Versions 4.3 and earlier have very poor filtering circuitry and have issues "hearing" other nodes.

Where to buy (ships to Canada)

• Rokland — Heltec, antennas, accessories. US-based, ships to Canada.
• LILYGO direct — T-Beam, T-Echo, T-Deck.
• RAK Wireless store — modular Wisblock ecosystem.
• AliExpress — cheapest, slowest, occasional clones. Verify the SX1262 chip for modern firmware compatibility.
• Local hams — ask in the YEG Discord. People often have spare boards.

What to spend your next dollar on

1. A better antenna.
2. Mounting it higher and clear of metal.
3. Lower-loss coax (and less of it).
4. Then a better board.