An effective currency needs to be widely accepted, easy to use, and stable in value. By now most of us have recognized that cryptocurrencies fail at all three things, despite lofty ideals revolving around decentralization, transparency, and trust. But that doesn’t mean that all digital currencies or payment systems are doomed to failure. [Roni] has been working on an off-grid digital payment node called Meshtbank, which works on a much smaller scale and could be a way to let a much smaller community set up a basic banking system.

The node uses Meshtastic as its backbone, letting the payment system use the same long-range low-power system that has gotten popular in recent years for enabling simple but reliable off-grid communications for a local area. With Meshtbank running on one of the nodes in the network, accounts can be created, balances reported, and digital currency exchanged using the Meshtastic messaging protocols. The ledger is also recorded, allowing transaction histories to be viewed as well.

A system like this could have great value anywhere barter-style systems exist, or could be used for community credits, festival credits, or any place that needs to track off-grid local transactions. As a thought experiment or proof of concept it shows that this is at least possible. It does have a few weaknesses though — Meshtastic isn’t as secure as modern banking might require, and the system also requires trust in an administrator. But it is one of the more unique uses we’ve seen for this communications protocol, right up there with a Meshtastic-enabled possum trap.

Wi-Fi! It’s everywhere, and yet you can’t really see it, by virtue of the technology relying on the transmission of electromagnetic waves outside the visual spectrum. Never mind, though, because you can always build yourself a Wi-Fi analyzer to get some insight into your radio surroundings, as demonstrated by [moononournation].

The core of the build is the ESP32-C5. The popular microcontroller is well-equipped for this task with its onboard dual-band Wi-Fi hardware, even if the stock antenna on most devboards is a little underwhelming. [moononournation] has paired this with a small rectangular LCD screen running the ILI9341 controller. The graphical interface is drawn with the aid of the Arduino_GFX library. It shows a graph of access points detected in the immediate area, as well as which channels they’re using and their apparent signal strength.

If you’re just trying to get a basic read on the Wi-Fi environment in a given locale, a tool like this can prove pretty useful. If your desires are more advanced, you might leap up to tinkering in the world of software defined radio. Video after the break.

Apple was all-in on WiFi from the beginning, launching the AirPort line of products to much fanfare in 1999. In 2004, along came the AirPort Express—a fully-functional router the size of a laptop charger, that offered audio streaming to boot. As [schvabek] found out that while a lot of older Apple gear has long ago been deprecated, the AirPort Express is still very much supported and functional to this day!

Generally, you wouldn’t expect to plug in a 20-year-old Apple accessory and have it work with the company’s modern hardware. However, upon slotting the AirPort Express into a wall socket and starting the initialization process, [schvabek] noted that it was detected perfectly well by his post-2020 Macs. Only, there was a small problem—the configuration process would always stall out before completion.

Thankfully, there was a simple remedy. [schvabek] found that he could connect to the AirPort Express with his classic white plastic MacBook and complete the process. From there, he was astonished that Apple’s servers let him pull down a firmware update for a device from 2004. After that upgrade, the AirPort Express was fully functional with all his modern Apple gear. He could readily stream audio from his iPhone and MacBooks with no compatibility issues whatsoever.

It’s nice to see Apple still supporting this ancient hardware to this day. It’s a nice contrast when companies like Sonos are more than happy to brick thousands of old devices just for the sake of progress.