Author: John Elliot V

167 Articles

UTF-8 brain lifting weights

Nic Barker Explains ASCII, Unicode, And UTF-8

January 22, 2026 by 12 Comments

Over on YouTube [Nic Barker] gives us: UTF-8, Explained Simply.

If you’re gonna be a hacker eventually you’re gonna have to write software to process and generate text data. And when you deal with text data, in this day and age, there are really only two main things you need to know: 7-bit ASCII and UTF-8. In this video [Nic] explains 7-bit ASCII and Unicode, and then explains UTF-8 and how it relates to Unicode and ASCII. [Nic] goes into detail about some of the clever features of Unicode and UTF-8 such as self-synchronization, single-byte ASCII, multi-byte codepoints, leading bytes, continuation bytes, and grapheme clusters.

[Nic] mentions about UTF-16, but UTF-16 turned out to be a really bad idea. UTF-16 combines all of the disadvantages of UTF-8 with all of the disadvantages of UTF-32. In UTF-16 there are things known as “surrogate pairs”, which means a single Unicode codepoint might require two UTF-16 “characters” to describe it. Also the Byte Order Marks (BOM) introduced with UTF-16 proved to be problematic. Particularly if you cat files together you can end up with stray BOM indicators randomly embedded in your new file. They say that null was a billion dollar mistake, well, UTF-16 was the other billion dollar mistake.

tl;dr: don’t use UTF-16, but do use 7-bit ASCII and UTF-8.

Oh, and as we’re here, and talking about Unicode, did you know that you can support The Unicode Consortium with Unicode Adopt-a-Character? You send money to sponsor a character and they put your name up in lights! Win, win! (We noticed while doing the research for this post that Jeroen Frijters of IKVM fame has sponsored #, a nod to C#.)

If you’re interested in learning more about Unicode check out Understanding And Using Unicode and Building Up Unicode Characters One Bit At A Time.

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A hand holding the Zoyi ZT-QB9 Smart Clamp meter

Review And Demo Of The Zoyi ZT-QB9 Smart Clamp Meter

January 18, 2026 by 14 Comments

Over on YouTube [Kiss Analog] reviews the New Zoyi ZT-QB9 Smart Clamp meter.

If you’re putting together an electronics lab from scratch you absolutely must get a multimeter to start. A typical multimeter will be able to do current measurements but it will require you to break the circuit you’re measuring and interface it to your meter using its mechanical probes.

A good choice for your second, or third, multimeter is a clamp-based one. Many of the clamp meters have the clamp probe available for current measurements while still allowing you to use the standard 4mm banana jack probes for other measurements, particularly voltage and resistance.

If you’re curious to know more about how clamp meters work the answer is that they rely on some physics called the Hall Effect, as explained by the good people at Fluke.

In the video the following clamp meters are seen: Zoyi ZT-QB9, PROVA 11, and Hioki CM4375. If you’re in the market for a clamp meter you might also like to consider the EEVblog BM036 or a clamp meter from Fluke.

We have of course posted about clamp meters before. Check out Frnisi DMC-100: A Clamp Meter Worth Cracking Open or ESP32 Powers DIY Smart Energy Meter if you’d like to know more. Have your own trusty clamp meter? Don’t need no stinkin’ clamp meter? Let us know in the comments!

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[Dr Ali Shirsavar] drawing schematics and equations on the whiteboard

Calculating The Capacitance And ESR Specifications For The Output Capacitor In Your Switching-Mode Power Supply

January 18, 2026 by 13 Comments

[Dr Ali Shirsavar] from Biricha Digital runs us through How to Select the Perfect Output Capacitor for Your Power Supply. Your switching-mode power supply (SMPS) will require an output capacitor both to iron out voltage swings due to loading and to attenuate ripple caused by switching. In this video we learn how to calculate the required capacitance, and when necessary the ESR, for your output capacitor.

To begin [Dr Ali] shows us that in order to calculate the minimum capacitance to mitigate voltage swings we need values for Δi, Δv, and Ts. Using these we can calculate the minimum output capacitance. We then need to calculate another minimum capacitance for our circuit given that we need to attenuate ripple. To calculate this second minimum we need to change our approach depending on the type of capacitor we are using, such as ceramic, or electrolytic, or something else.

When our circuit calls for an electrolytic capacitor the equivalent series resistance (ESR) becomes relevant and we need to take it into account. The ESR is so predominant that in our calculations for the minimum capacitance to mitigate ripple we can ignore the capacitance and use the ESR only as it is the feature which dominates. [Dr Ali] goes into detail for both examples using ceramic capacitors and electrolytic capacitors. Armed with the minimum capacitance (in Farads) and maximum ESR (in Ohms) you can then go shopping to find a capacitor which meets the requirements.

If you’re interested in capacitors and capacitance you might enjoy reading about Measuring Capacitance Against Voltage and Getting A Handle On ESR With A Couple Of DIY Meters.

A hand operating a numeric touch pad

Building An Escape Room Lockbox With The ESP32 Cheap Yellow Display (CYD)

January 15, 2026 by 4 Comments

Here’s something fun from [Chad Kapper] over on HackMakeMod: Escape Room Lockbox with the Cheap Yellow Display.

You may have heard of the “cheap yellow display” (CYD), so-called due to the board’s typical color. It’s a dodgy cheapo board with, among other things, TFT display, touchscreen, and ESP32 built-in. You can learn more about the CYD over here: Getting Started with ESP32 Cheap Yellow Display Board – CYD (ESP32-2432S028R).

In this build eight AA batteries are used to deliver 12 volts to operate a solenoid controlling a latch and 5 volts for the microcontroller. The encasing is clear in order to entice players in an escape-room style sitting. The custom software is included down the bottom of the project page and it is also available from arduino.cc, if that’s your bag.

Of course we’ve done plenty of other ESP32 TFT projects before, such as Piko – Your ESP32 Powered Fitness Buddy and ESP32 Brings New Features To Classic Geiger Circuit.

The Atari 800

Atari Brings The Computer Age Home

January 13, 2026 by 37 Comments

[The 8-Bit Guy] tells us how 8-bit Atari computers work.

Personal Computer Market Share in 1984The first Atari came out in 1977, it was originally called the Atari Video Computer System. It was followed two years later, in 1979, by the Atari 400 and Atari 800. The Atari 800 had a music synthesizer, bit-mapped graphics, and sprites which compared favorably to the capabilities of the other systems of the day, known as the Trinity of 1977, being the Apple II, Commodore PET, and TRS-80. [The 8-Bit Guy] says the only real competition in terms of features came from the TI-99/4 which was released around the same time.

The main way to load software into the early Atari 400 and 800 computers was to plug in cartridges. The Atari 400 supported one cartridge and the Atari 800 supported two. The built-in keyboards were pretty terrible by today’s standards, but as [The 8-Bit Guy] points out there wasn’t really any expectations around keyboards back in the late 1970s because everything was new and not many precedents had been set.

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ARCTURUS control panel

The ARCTURUS Computer Developed At Sydney University In The 1960s

January 12, 2026 by 5 Comments

[State of Electronics] have released their latest video about ARCTURUS, the 14th video in their series The Computer History of Australia.

ARCTURUS was a research computer system developed on a shoestring budget at Sydney University in the 1960s, and was in service until 1975. Particularly the system was developed by [David Wong] as a part of his PhD thesis: The design and construction of the digital computers snocom, nimbus and arcturus (PDF). [David] worked in collaboration with [Kevin R. Rosolen] who is interviewed in the video.

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An LDO schematic and some notes about their features

Texas Instruments Explain Low-Dropout Linear Voltage Regulators

January 10, 2026 by 13 Comments

Today in power electronics, the folks over at Texas Instruments have put together a video covering low-dropout (LDO) linear regulators.

For a hacker, power is pretty fundamental, so it behooves us to know a little bit about what our options are when it comes time to regulate power to our projects. In this video [Alex Hanson] from Texas Instruments runs us through the linear voltage regulators known as low-dropout regulators (LDOs). It turns out that LDOs are often a poor choice for voltage regulation because they are inefficient when compared to switching regulator alternatives and can be more expensive too.

So when might you use an LDO? In very low power situations where heat and efficiency doesn’t matter very much. LDOs operate best when the input voltage is very near the output voltage and when current demands are low (roughly speaking less than ~50 mA is okay, ~500 mA is maximum, and some applications will support 1 to 3 A, although not with great efficiency and in this case thermal emissions — or magic smoke! — will become an issue).

What LDOs bring to the table is relatively clean and low-noise voltage as well as low dropout voltage (the minimum difference between the input and output voltage needed for regulation), which is their defining feature. What’s more with an appropriate output capacitor they can react quickly to load changes and they usually emit minimal EMI. LDOs are not about efficiency, they are about quality, simplicity, and control.

You might like to read more about when linear regulators might be the right choice or what your other options are.

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