Making Stuff Blog

AP22815/AP22615/et al USB-friendly load switches from Diodes Inc. 2 months ago
tl;dr: These are two load switches in a series of similar SOT-23-5/SOT-23-6 load switches that make it really easy to get power safely from a USB port. One of the important rules about getting power to a device from USB is that you need to make sure that your USB device doesn't try to back-power the…

Trying out Ponoko and the FreeCAD Laser Cut Interlocking workbench 5 months ago
tl;dr: The Laser Cut Interlocking workbench is the first tool I've found that feels like it might make the process of designing three dimensional structures to be laser cut easier. And Ponoko is kinda neat once you get past the $14 per-order charge Why is laser cutting cool? I should probably…

Gate driver test: PWM switching a half-amp at 80 kHz PWM with a MOSFET 6 months ago
tl;dr: At 80 kHz where the MOSFET switches 0.5A at 5V, a gate driver makes a small but measurable difference in switching speed. It makes a clear difference in heat generated as you switch increasing amounts of power. It's better to do PWM at a high frequency. Ideally, you want the frequency to be…

A vaguely finished ESPHome node for my geekroom 6 months ago
Some five months ago , I wrote about how I got started with ESPHome with an ESP8266 and a temperature/humidity sensor on a breadboard. I figured that I'd build it over time. I'd realize that there would be something that would be really nice to add, and so I'd find some parts to do it, or try out…

Making an ATMega32U4 Arduino clone board from scratch 6 months ago
So far, the Ardunio environment seems to be the easiest way for me to get real and practical things done with hardware, most of which has to do with there being a decent open-source library for most of the things that I could write but don't want to. I've never actually purchased a real Arduino…

The missing bits for how to make a QMK macro pad from scratch: Writing a firmware for a custom board 7 months ago
At some point, I was linked to Ruiqi Mao's guide on how to make a keyboard PCB in KiCad and kinda filed in the back of my head the idea of doing that. Because, honestly, PCB design is kinda fun. Eventually, I decided there were enough interesting reasons all coupled to making a ATMega32u4 board…

MD3 v3 fully-analog solar thingie 8 months ago
One of the tenets of the whole BEAM robotics thing was that folks should be making their creations out of easily accessible electronic parts of the sort you could scavenge out of dead electronics or find in Radio Shack. In the time since then, Radio Shack disappeared and it's much harder to…

DigiKey's KiCad library is really broken 9 months ago
tl;dr: Don't use DigiKey's KiCad library. Obviously, you shouldn't trust random libraries on the Internet. Heck, you shouldn't trust the actual KiCad libraries most of the time. I'm still annoyed about this because I've got a pack of useless PCBs. DigiKey, for whatever reasons, has been trying to…

TLC5940, TLC59116, and IS31FL3218 LED drivers 10 months ago
tl;dr: The TLC59116 is a pretty neat part Following up to the previous entry on the CAT4019/CAV4019 LED driver , I got three more intelligent controllers to play with. All three of these are external intelligent LED drivers, two from TI, one from Lumissil. I soldered the three of them to surface…

Three and a half new ways to deep sleep in ESPHome 10 months ago
I've been wanting to do some stuff with solar power and low energy and ESPHome. Thing is, either of those devices eats up quite a bit of current. Less than a Pi, but still enough power to matter if you are using solar power. Furthermore, I think that ESPHome's over-the-air software update system…