A place to learn about coding, making things, and stuff that strikes my fancy.
When we used NPN transistors to build our logic gates, it implies they can be used for building bigger things. In this video I've built a full 1 bit adder from our second Introduction video, entirely from discrete transistors. Build 8 of these--and you have an 8-bit adder. The show notes include the complete circuit... Continue Reading →
It took another couple of tries, and the trick for these gears was to get the outer diameter to within 0.002". Further, it required depthing the teeth to 1/32" == 0.625" (the precise measurement of the depth of the teeth) rather than cutting them a hair deeper. And I'm suspicious the Sherline divider may not... Continue Reading →
It probably doesn't help that I have no idea what I'm doing. Though I do have all my fingers and toes. So there's that. So today, after getting the M3 to M2 adapter, the M2 to Sherline adapter, and hooking up the Sherline 4-jawed chuck to the larger 7" lathe, I went to round the... Continue Reading →
So if you've been watching my Quick Videos you know I've been building a lot of circuits on prototype boards. I also took the liberty of 3D printing a couple of useful tools to help measure and bend wire. The first on the left helps measure lengths of wire; each wire is measured in each... Continue Reading →
So, as promised, about a month later, the second video in my series of videos explaining how computers work from the ground up. And I mean truly, the ground up; on a breadboard next to me I have a working 1-bit adder circuit made entirely out of 10KΩ resistors, 2N3904 transistors, a few LEDs and... Continue Reading →
Of course one of the purposes of the "Introduction to Digital Computers" video series is to create a series of videos which describe how computers work from a transistor level--and starting with NPN transistors so in theory you could build this yourself. Because the idea is that I want computers not to be this strange... Continue Reading →
We've been having problems with our Internet connection, and I also maintain an e-commerce web site which I'd like to make sure is working correctly. This quick little hack uses the following parts to periodically check that your web site is running: Arduino-compatible Adafruit Metro 328 Ethernet Shield for Arduino 9 VDC power adapter Arduino-compatible... Continue Reading →
So one downside of the superglue arbor is that you really need to clean up the end of the arbor holding your gear--and you need to apply enough glue to get the gear to stick to the arbor. More than once today I had wheels fall off the arbor--and that led to... well, complications. I... Continue Reading →
So I drew and cut out several blanks from the 1/8th inch aluminum (and I confess I had to do this several times, by the last blank I was very close to the line) using a scroll saw and a jeweler's blade. I then perfected them on the Sherline Lathe to the correct diameter of... Continue Reading →
