Category Archives: Microcontrollers

Interactive art at Helix

Romy Randev of Looma is installing his latest piece, Penumbra at the Helix museum in Los Altos.

Penumbra is an interactive installation that responds to movement in its environment. Without any human interaction, Penumbra is disguised as a decorative glass wall. However, each colored glass tile illuminates individually as sensors that respond to movements control LEDs behind the glass.

Penumbra makes use of our Octolively modules, and we’ll be at Helix with Romy on Saturday March 29th, starting at 2:00 PM to talk about the art and tech behind Penumbra. Event information is available from Helix.

Basics: AVR Target Boards and Arduino Compatibility

Gary writes:

I have fallen in love with your Diavolinos – thank you!
My question: does the “Simple target board” allow for the 6-pin FTDI Friend hookup to upload sketches? This is quick and easy with the Diavolino. I’m new to reading circuits and stuff, and I cannot tell looking at the target board. It says to use in-system programmer, but I prefer to not buy another interface. Thanks!

Excellent question! It is certainly possible, but not as quick and easy.  Both the Diavolino and our ATmegaXX8 target boards boards use the same chip, usually the ATmega328P.  But, one might say that our ATmegaXX8 board is a simple AVR target board optimized for use with an AVR ISP programmer (like the USBtinyISP), whereas the Diavolino is a simple target board optimized for use with the FTDI interface.

XX8 Target Board

Versus a “bare” target board (with just the chip and power), there are four things that you would normally add, in order to use the FTDI interface to upload a sketch from within the Arduino environment:

Continue reading Basics: AVR Target Boards and Arduino Compatibility

Larson Scanner modding


Anton wrote in to ask:

I want to purchase your Larson Scanner kit but need to be able to run it from household current … is there a converter that you would recommend?

Since the Larson Scanner normally runs from 3 V DC, a regulated 3 V power supply can be hooked up in place of the 2xAA battery box. However, 5 V power supplies (like this one) are much more common, and the circuit can be run from 5 V with only minor changes. if you replace the nine 16 ohm resistors in the Larson Scanner kit with 120 – 150 ohm resistors, you can power it from 5 V directly.

Another related question we occasionally get is how to run the Larson Scanner with green LEDs. (Note: by green, we mean “pure” green LEDs which have a forward voltage of about 3 V. Older style yellow-green LEDs with a forward voltage of ~2 V can be used as drop-in replacements for the red ones.) 

If running off of battery will work for you, this is an even simpler change: merely replace the 3 V battery holder with a 4.5 V one, such as a 3xAA. It is a happy coincidence that the circuit can run with red LEDs at 3 V or green LEDs at 4.5 V using the same 16 ohm resistor value. So how about running a green Larson Scanner from a 5 V power supply? Replace the nine 16 ohm resistors with 39 ohm resistors and you should be good to go.

You can find the documentation for the Larson Scanner and more stories about modding it on our wiki. We’d love to hear about any mods you do to the Larson Scanner in the comments or see pictures in the flickr pool.

Access Point Garage Door Opener

Over at Dead, too much lettuce., Scott built an Access Point garage door opener with a Raspberry Pi, an Arduino, and our Simple Relay Shield.

I bike to work. Bikes live in the garage. But with only 2 remotes, I could not keep one in my bag all the time to be able to get to the bike. So a new option had to be created. Most people would have bought a new remote…

LED Kitchen Timer

Dave wrote in to tell us about the kitchen timer he made:

I just wanted to say thank you for putting together such a great site and set of products. I’m a newbie and after about 4 months o studying your articles and using the Diavolino as my development board, was able to make a cool little kitchen timer for my parents this Christmas. I definitely could not have done it without your articles and products.

He documented the project with a series of videos (youtube playlist) showing his progression through building it. Shown above is the breadboarded prototype next to the finished timer.

Thanks for sharing your project photos and videos, Dave!

Breadboard Menorah Kit Instructions

aberson asked about our new Deluxe Electronic Breadboard Menorah kits:

Would it be possible to post the assembly instructions for the solderless kit? (if there are any) I’m wondering if this kit would be suitable for somebody who has no electronics experience at all. Does it call out the row/col number for every resistor, jumper, etc?

Printed instructions do come with the kit, are very helpful, because there’s an actual size component bending guide on the page. We have also posted a pdf version on our documentation site. No prior knowledge of electronics is needed, and we call out the location for each component and provide clear diagrams to follow.