A black screen with green text is shown. The green text logs events from a VPN gateway.

Running A VPN Gateway On An ESP32

If you need a VPN gateway to access your home network, the fastest and most cost-effective way is probably by using a Raspberry Pi Zero. But in [Samir Makwana]’s view, an ESP32-S3 is just as capable for moderate use, and in some respects even superior.

This was possible thanks to the MicroLink project, which is a full implementation of a Tailscale client for the ESP32 family. In some ways the ESP32 worked better than a Raspberry Pi: it boots in two seconds rather than thirty, draws 0.5 Watts rather than 1.5, and there’s no chance of it failing due to a corrupted SD card. Compared to a Raspberry Pi, however, which can be set up as a Tailscale client in a few minutes, this took several hours to get running. The biggest issue was making sure that there was enough memory available for TLS handshakes, which was solved by enabling the ESP32’s PSRAM.

Once the VPN client is running, the ESP32 can be used as an SSH jump machine to access other devices on the home network, without needing to expose those machines to the open Internet. The ESP32 also hosts an HTTP server which can send a wake-on-LAN magic packet to another device on the local network, letting unused devices sleep without impairing their availability.

The ESP32 doesn’t provide much bandwidth — streaming video would cause issues — but it works well enough for lightweight applications. If you’re wanting to stream video from an ESP32, though, it is technically possible.

Building A Working Replica Of The Chernobyl Power Plant’s SKALA Display

In a recent video by the [Chornobyl Family] it’s shown how they made the SKALA status display which was featured at the recent 40-year memorial exhibition of the Chornobyl Nuclear Power Plant (ChNPP) #4 reactor accident, along with the RBMK reactor control panel replica and SKALA console which they had made previously.

Detail of the SKALA display. (Credit: Chornobyl Family, YouTube)

We previously covered this SKALA control system of the ChNPP’s RBMK reactors, as well as its 1990s modernization. This SKALA status display is one of the original elements of the control room, providing a status overview of the entire control system at a glance, including its processors and peripheral devices.

The replica uses similar looking components, with a metal casing and LED lighting that invokes the aesthetics of the original electroluminescent mnemonic panels. Overall the goal was to keep the appearance as close to the original as possible — they even had operators of the ChNPP reactors look over the panel and give it their stamp of approval.

Some of the components like the error indicators had to be 3D printed, while the metal case was cut out of sheet metal. There’s also a very big speaker for the alarm, at the top right of the panel. Along with the LEDs for the electroluminescent-style indicators this meant a lot of addressable LEDs and a lot of wiring.

The full build plans are available via the [Chornobyl Family] Patreon, if you feel like building up your own RBMK-style reactor control room.

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