in Verilog Code — LCD display technology has been around for a long time, long before the advent of LCD TVs that have vibrant colors. In this article, we are focusing on this LCD1602 character LCD. LCD1602 (or HD44780 as one of its key components) has two rows, each of which can display 16…

Mental Math Rule Derived from Slide Rule — With the global hot summer months dwelling, it is sometimes useful to compare the daily temperatures of big cities around the world. In most places, local residents are used to temperature units in Celsius, except US and a few places where Fahrenheit is still in use. (https://worldpopulationreview.com/country-rankings/countries-that-use-fahrenheit) Fortunately there exists…

Light Blaster and Archery — In the Star Wars galaxy far far away, light (or laser) blaster pistols or rifles are the common weaponry used by stormtroopers, Mandalorians, among others. Once fired, its “bullet” trajectory is illuminated by a burst of light beam, thus called light bullet. Along with lightsabers, they are often thought of…

Graph Method and Slide Rule — There is a saying, the starting point of any software programming is to be able to print “Hello World” to a console. Similarly the simplest embedded programming task is to have MCU flash one LED using its GPIO pin. To extend that, the simplest circuit design problem is to size…

using slide rule for ratio calculation — For a DIY project, I need to drill mounting holes for M2.5 (metric) screws. I happen to own ANSI (imperial) drill bits set only, which comes in 1/64 inch increments. Fortunately, there is a screw gauge template in the box, which allows me to trial fit the M2.5 screw one-by-one…

Continued Fraction Method — Some slide rule has a “A” scale for x², which can be used to look up square root values quickly. However there are plenty of slide rules that doesn’t come with “A” scale. How can you calculate square root, simply using division? Either by hand, or in this article, by…

Part 1 — Nowadays most programming related book authors open the book preface with his/her cherished childhood memory of being introduced to a commodore computer or BASIC programming language at an early age. My son is 8-yr old now. I haven’t introduced him to programming. For fear of missing out that paragraph in…

a quick way to avoid MS build toolchain — Say you want to play with Rust on a Windows machine. Rust comes with a native installer for Windows, but that requires you to download and install MS C/C++ build tools first (several GB). Here is a quick way to avoid doing that. On Windows side, make sure WSL remote…

how to place the decimal point — Whether you are multiplying 1200 by 4, or 120 by 4, it is all represented as 1.2 x 4 on a slide rule. As the result is read out to be 4.8, where to place the decimal point? Except for simple cases that you can estimate the results, it’s often…