DIY Walkie-Talkie With ESP32 And ESP-NOW

In a recent article in Elektor magazine, [Clemens Valens] describes the construction and software for an ESP32 walkie-talkie system that uses ESP-NOW for the wireless connection between units, along with a low-cost condenser microphone with a transistor-based preamplifier and an LM386 op-amp for the speaker circuit. In the ESP32 module the built-in DAC and ADC are used for audio in and output, which provide just about enough resolution for voice communication.

So why use ESP-NOW rather than WiFi or Bluetooth? Mostly because of range, power usage and convenience with no SSIDs and passwords to bother with.

The DIY Walkie-Talkie circuit diagram. (Credit: Clemens Valens, Elektor magazine)
The DIY Walkie-Talkie circuit diagram. (Credit: Clemens Valens, Elektor magazine)

ESP-NOW is Espressif’s own network protocol that uses the same underlying hardware as 2.4 GHz WiFi and Bluetooth, but focuses on more basic direct and mesh-style communication. It can be considered to be somewhat like low-level UDP with MAC address instead of IP address, which makes it useful for fire-and-forget traffic such as from IoT devices.

In the past, we’ve seen ESP-NOW control everything from fake security cameras to CNC machines. In fact, we’ve even seen it used in another walkie-talkie a couple years back.

This Week In Security: LogoFail, National DNS Poison, And DNA

When there’s a vulnerability in a system library, we install updates, and go on with our lives. When there’s a vulnerability in a Java library, jars get rebuilt, and fixed builds slowly roll out. But what happens when there’s a vulnerability in a library used in firmware builds? And to make it even more fun, it’s not just a single vulnerability. All three major firmware vendors have problems when processing malicious images. And LogoFail isn’t limited to x86, either. UEFI Arm devices are vulnerable, too.
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The Latest John Deere Repair Lawsuit Now Has The Go-Ahead

Long time readers will have followed the twists and turns of the John Deere repair saga, in which the agricultural machinery manufacturer has used DRM to restrict the repair of its tractors. It may be hot stuff on the prairies, but it matters to everyone because it’s a key right-to-repair battleground. Now the company’s attempt to throw out the latest class-action lawsuit, this time in Illinois. has failed, paving the way for a meaningful challenge.

This lawsuit is special because has the aim of determining whether or not Deere conspired to drive up the cost of repair and edge out independent mechanics. It comes against a backdrop in which their promised access to repair software which we reported on back in January has failed to materialize, and this is likely to figure as an act of bad faith.

A failing of corporate culture is that the organisation can in its own eyes, never be wrong. In Deere’s case they have accrued plenty of bad publicity in the years they’ve pursued this ill-advised business model, and in case that weren’t enough they’ve alienated their core customers out on the farms to the extent that a second-hand Deere from before the DRM era has more value than its newer counterparts. Deere genuinely do make very good tractors, so for farmers loyal for generations to turn their backs on them is a very significant story indeed. One has to ask, how much bad publicity and how many lawsuits do they have to have before someone at head office in Moline figures out that DRM in tractors (or anything else for that matter) isn’t the great idea they once thought it was? Maybe this one will finally herald the moment when that happens.

Header image: Nheyob / CC BY-SA 4.0

Festive PCB Gives The Gift Of Hacking

‘Tis the season for gift giving, and what better to give than a newfound love for hacking, soldering, and blinkenlights? In order to spread cheer and education at the local hackerspace, [Tom Goff] created this festive tree circuit board that can either sit in a stand to be admired, or worn as jewelry. The resistors are even designed to look like candy canes hanging from the boughs.

The brains of this festive little tree is an ATmega328P, which you probably recognize as the microcontroller that powers the Arduino Uno. Although this circuit has none of the extra bits you’d find on an Uno, not even a crystal oscillator, it can still be programmed with Arduino and use the 8 MHz internal clock.

[Tom] has provided good, thorough instructions, especially for the sticky bit of setting up the IDE to program using the 8 MHz internal clock. So even if you’re nowhere near Norwich Hackerspace, you can join in the fun. Be sure to check out the video after the break, wherein [Tom] walks through designing the PCB using Inkscape and Fritzing.

Want to whip up a little something for the hackerspace wall? Check out this Sierpinski Christmas tree.

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