Category Archives: Electronics

Circuit Classics

We’re very excited about the Circuit Classics PCBs and kits that Star Simpson is making based on Forrest Mims designs.

Each circuit depicts an original, traced and hand-drawn schematic created by Forrest Mims for his iconic books “Getting Started in Electronics”, and the “Engineers’ Notebook” series. Every board includes a description of how it works, in Mims’ handwriting, on the reverse side.

They look like a fantastic way to learn electronics. You can order them through her Crowd Supply campaign now.

From the mailbag: XL741 in the classroom

S.W. wrote in:

I just wanted to let you know that I am using your XL741 kit in my Electronics 2 class lab. It is a high quality kit and I thank you for putting it together. We build the 741 in stages, make measurements, adjust offsets, etc. It is a great vehicle to teach the analog building blocks. A student of mine (now graduated) and I wrote four lab exercises for it and they are being used now for the second time. We also just got to share them with several EE teachers who were also very enthusiastic about the idea.

We love to hear about how our kits get used!

555 Teardown

Ken Shirriff has posted a teardown of the beloved 555 timer IC. He sawed the top of a metal can packaged 555 to expose the die underneath.

On top of the silicon, a thin layer of metal connects different parts of the chip. … Under the metal, a thin, glassy silicon dioxide layer provides insulation between the metal and the silicon, except where contact holes in the silicon dioxide allow the metal to connect to the silicon. At the edge of the chip, thin wires connect the metal pads to the chip’s external pins.

He goes on to explain how it works and its cultural significance. He even mentions our discrete 555 and 555 footstool in the footnotes.

From the mailbag: Bristlebots and Scribblebots

Kate K.'s Bristlebot bug (Courtesy of Jessica K.)

Jessica K. wrote in:

A few years ago I used your bristlebot design for one of my kid’s classes as a project and it was such a success I’ve done it for each kid (I have 4).

Kate K's Bristlebot Ladybug bottom (Courtesy of Jessica K.)

We also made made “pontoon” versions of your bristlebots with 2 toothbrush ends underneath a cardboard oval so it looked like a beetle and gave the kids more decorating space.

Scribblebot parts (Courtesy of Jessica K.)

Well, now I needed a new project and I came up with the easiest, cheapest Scribblebot I’ve come across, using mostly your bristlebot construction.

Kate K.'s Dixie Scribblebot (Courtesy of Jessica K.)

The big discovery is that a Dixie cup plus mini markers keeps the whole thing so lightweight. Then put your foam taped pager motor and battery combo on top. It was also way cuter with some antennae and googley eyes. Thank you again for your great bristlebot – it’s made me the most popular mom in each of my kids’ classes.

The bots shown were made by her daughter Kate who also demonstrates them in the video clips. Thank you Kate & Jessica!

Epic Cylon costume with Larson Scanner

By Warren Goodwin

Warren wrote in on Facebook:

I just received your Larson scanner for my Foam Cylon helmet today … I have since this video diffused the light inside the clear conduit pipe the LEDS are held inside of to make the LED effect a bit more smoother.

He has been posting updates of the costume on facebook.

Cylon costume with Larson Scanner eye
By Warren Goodwin

RGB Interactive Table

IR_Table

Craig shared this project which evolved with the assistance of the Octolively project.

Thanks for the previous help you gave me when I was designing my own IR proximity boards. I thought you may want to have a look at the finished item.

I have attached a picture of the 25 100mmx100mm boards and a video of the table working. Each one had a SOIC PIC 18F26K22 on it, with 9 IR transmitters and receivers and 9 x WS2812b addressable LEDs on. They all kind of communicate with each other so that each board does the same IR reading of the same ‘pixel’ at the same time as the others. I simply have a pin on the board which outputs low whan it is working (taking a reading’, then after it is done, it changes to an input pin, it continually looks at this pin until it goes high, meaning all the other boards have also completed that particular reading and then it’s on to the next one.

I also have a calibration function so any thickness opaque covering can be put on the table top.

I have 2 buttons on it. One to change the colour (including the rainbow fade) and also a button to change the fade speed.

IR_Table

Thank you, Craig, for sharing your project! We’re glad you were able to get inspiration and helpful information from one of our projects.

 

 

Interactive LED Christmas Tree

LED Christmas tree on Octolively derivative boards

Our friends at Mouser sent us this picture of their Octolively derived display, updated for the holidays:

We continue to have fun with your Octolively module design. In the attached photo you can see why we decided to use sockets for the LEDs on our boards.  We plan on changing out the display for each of the holidays.

I was a little concerned at first about using the red LEDs with resistors that were chosen for white or blue, but they’re socketed, so replacing any that get damaged by overdriving should be easy! Looks like a fun way to celebrate at the office, and the snowflake tree-topper is a nice touch.

DIY Mega Menorah 9000

LEDs in breadboard

Over on twitter, @shaiss says:

This is why #OSHA is awesome! In a pinch+some parts we made our electronic menorah. @EMSL design &  @adafruit trinket.

If you want to roll your own, the open source hardware documentation is on our wiki. If you’re not keen on the breadboard aesthetic for your hanukkiyah, you can still get the Mega Menorah 9000 kit.