Here’s a video of my very hackable 12-channel logic level shifter/translator with a voltage regulator. This video demonstrates how it works. There’s more detail here at the post. In this example, it’s translating from 7.5V to 3.3V. In another example…
40-pin female headers are inexpensive and easy to trim down to size, and with a dot of CA glue (super glue), you can even easily make other configurations, like 2×4. Sometimes they’re even described as “break-away” headers, although admittedly they…
He we’re test-driving the our latest robot creation for the first time. It’s the boy’s design and made mostly of wood. The tires are o-rings, and there’s a 12V AA batter pack sandwiched between the two pieces of plywood. The…
Here’s a 12-channel bidirectional logic level shifter with a 3.3V power regulator that I designed so I could easily interface 5V circuits with cool 3.3V widgets like the ADXL345 accelerometer, the NRF24L01+ wireless transceiver, and the Nokia 5110 84×48 LCD. For the…
I used the excellent Quick KICAD Library Component Builder recently to build a new component for eeschema in KiCAD, but when I imported the library, I got an error dialog that said, “Library component load error error <error <pin only…
Before I placed my order, I had questions about Seeed Studio Fusion PCB service turn-around time for shipping to the USA, and so I figure others might as well. Here are details of my order of the ten 5cm square…
Here’s an Arduino-compatible GI-SP0256-AL2 speech synthesizer module that I’m finishing up. It’s a great 1980’s-era allophone speech synthesizer chip that was used in Intellivision expansion modules and sold at RadioShack stores for years for about $12. You can still find…
We finished up PopsicleBot StickBot with a couple of 555 timer circuits to allow it to roam freely and untethered. It was a lot of fun to build, and even though it’s not the fastest walker or the simplest design, it…
Here’s a small, inexpensive, modular, and easy-to-customize motor controller I’m working on that incorporates the Modern Device RBBB ($13), and Pololu’s TB6612FNG Dual Motor Driver Carrier ($8.50). If I fry or want to retask the brain or the driver or…
Here’s a little SQL gymnastics used to parse and query against a predictably-formatted long text field. The challenge: We have a single text field that contains a list person_id-to-area mappings, and we need the query the database for a list…