Review: Calculator Kit Is Just A Few Hacks From Greatness

July 2, 2020 by Tom Nardi 48 Comments

While most people are satisfied with a calculator application on their smartphone these days, there’s still something to be said for the old fashioned desk calculator. Maybe it’s the fact the batteries last long enough that you can’t remember the last time you changed them, or the feel of physical buttons under your fingers. It could even be the fact that it keeps your expensive smartphone from needing to sit out on the workbench. Whatever the reason, it’s not uncommon to see a real-life calculator (or two) wherever solder smoke tends to congregate.

Which is precisely the idea behind this DIY calculator kit. Available from the usual overseas retailers for about $15 USD, it has some hobbyist-oriented features such as the ability to decode resistor color bands, convert hexadecimal numbers, and calculate resistor values for driving LEDs. If you’re going to keep a knock-around calculator on your bench, why not build the thing yourself?

Given the dual nature of this product, a DIY electronics kit and a functional desk calculator for electronic hobbyists, it seems only appropriate to review both aspects of it individually. Which is good, since there may be more to this product than just the sum of its parts.

Continue reading “Review: Calculator Kit Is Just A Few Hacks From Greatness” →

Books You Should Read: The Boy Who Harnessed The Wind

May 14, 2020 by Steven Dufresne 30 Comments

For many of us, our passion for electronics and science originated with curiosity about some device, a computer, radio, or even a car. The subject of this book has just such an origin. However, how many of us made this discovery and pursued this path during times of hunger or outright famine?

That’s the remarkable story of William Kamkwamba that’s told in the book, The Boy Who Harnessed the Wind. Remarkable because it culminates with his building a windmill (more correctly called a wind turbine) that powered lights in his family’s house all by the young age of fifteen. As you’ll see, it’s also the story of an unyielding thirst for knowledge in the face of famine and doubt by others.

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New Teensy 4.1 Arrives With 100 Mbps Ethernet, High-Speed USB, 8 MB Flash

May 11, 2020 by Ted Yapo 83 Comments

It was only last August that PJRC released Teensy 4.0. At that time, the 4.0 became the fastest microcontroller development board on the planet, a title it still holds as of this writing — or, well, not exactly. Today the Teensy 4.1 has been released, and using the same 600 MHz ARM Cortex M7 under the hood, is now also the fastest microcontroller board. What the 4.1 brings to the table is more peripherals, memory, and GPIOs. While Teensy 4.0 used the same small form factor as the 3.2, Teensy 4.1 uses the larger board size of the 3.5/3.6 to expose the extra goodies.

The now slightly older Teensy 4.0 — released on August 7th of last year — is priced at $19.95, with the new 4.1 version offered at $26.85. It seems that the 4.1 isn’t intended as a replacement for the 4.0, as they serve different segments of the market. If you’re looking for an ultra-fast affordable microcontroller board that lives up to its Teensy name, the 4.0 fits the bill. On the other hand, if you need the additional peripherals broken out and can afford the space of the larger board, the not-as-teensy-sized 4.1 is for you. How big is it? The sample board I measured was 61 x 18 mm (2.4 x 0. 7″), not counting the small protrusion of the micro-usb jack on one end.

Let’s have a look at all the fun stuff PJRC was able to pack into this space. Continue reading “New Teensy 4.1 Arrives With 100 Mbps Ethernet, High-Speed USB, 8 MB Flash” →

Review: The Riden RD6006W DC Power Supply Module

March 16, 2020 by Jenny List 42 Comments

You may have seen the Ruideng range of programmable power supply modules from China: small and relatively inexpensive switch-mode buck converters, with microprocessor control and a front panel featuring a large colour OLED screen. Given 30 volts or so they can supply any lower voltage with the extra bonus of current limiting. They’ve been so successful over the several years they’ve been available that they’ve even spawned their own Chinese clones, and countless hacker projects, for instance on the DPS300X and DPS500X models.

Late last year a new module came from Ruideng, the Riden-branded RD6006 combines the basic idea of the previous modules with an extremely flexible front panel with full keypad and rotary encoder, creating something like the front panel to a decent bench power supply but without the accompanying power supply. I ordered one, waited for it to clear customs, took it to my bench, and reviewed it. Continue reading “Review: The Riden RD6006W DC Power Supply Module” →

Review: Unnamed Chinese DDS Function Generator

February 25, 2020 by Jenny List 31 Comments

Best forgotten: my awful 2018 function generator.

A lifetime of amassing random pieces of test equipment has left me with a gap in my armoury, namely that I don’t possess a low frequency function generator. This could easily be addressed, but for two things. I have a love for exploring the cheaper end of exported electronics and my need for a function generator is less than my desire to spend significant cash. I’ve tried to balance these competing forces in the past by picking up an astoundingly cheap instrument; that time I ended up with a lemon, but will lightning strike twice in the same spot? I spent £10 ($13) on a different cheap function generator and set off to find out. Continue reading “Review: Unnamed Chinese DDS Function Generator” →

Review: SanErYiGo SH72 Soldering Iron

January 27, 2020 by Jenny List 34 Comments

When the Miniware TS100 first emerged from China nearly three years ago, it redefined what we could expect from a soldering iron at an affordable price. The lightweight DC-powered temperature controlled iron brought usable power and advanced features in a diminutive package that was easy in the hand, a combination only previously found in much more expensive soldering stations. All this plus its hackability and accessible hardware made it an immediate hit within our community, and many of us have adopted it as our iron of choice.

A surprise has been that it has attracted no serious competitors of a similar type, with the only iron mentioned in the same breath as the TS100 being Miniware’s own USB-C powered TS80. Perhaps that is about to change though, as before Christmas I noticed a new Chinese iron with a very similar outline to the TS100. Has the favourite finally generated a knock-off product? I bought one to find out. Continue reading “Review: SanErYiGo SH72 Soldering Iron” →

Review: Testdriving LibrePCB Shows That It’s Growing Up Fast

January 22, 2020 by Jenny List 54 Comments

There are a host of PCB CAD tools at the disposal of the electronic designer from entry-level to multi-thousand-dollar workstation software. It’s a field in which most of the players are commercial, and for the open-source devotee there have traditionally been only two choices. Both KiCad and gEDA are venerable packages with legions of devoted fans, but it is fair to say that they both present a steep learning curve for newcomers. There is however another contender in the world of open-source PCB CAD, in the form of the up-and-coming LibrePCB.

This GPL-licensed package has only been in development for a few years. LibrePCB brought out its first official release a little over a year ago, and now stands at version 0.1.3 with builds for GNU/Linux, Windows, MacOS, and FreeBSD. It’s time to download it and run it through its paces, to see whether it’s ready to serve its purpose.

Continue reading “Review: Testdriving LibrePCB Shows That It’s Growing Up Fast” →