Basics: AVR Target Boards and Arduino Compatibility

Diavolino
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:

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Larson Scanner modding

larson3

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.

Evil Mad Scientist Laboratories Valentine Projects

LOLHearts - 34

We’ve rounded up our Valentine projects for your last minute preparations:

If one of our projects inspires you make something, we would love to hear about it in the comments or see photos in the flickr pool!

Muybridge Carousel for Eggbot

The Horse In Motion

In the 1870s, Eadweard Muybridge, using brand new photographic techniques, helped settle a bet about whether horses lifted all their feet off the ground at once. His iconic pictures of horses in motion are frequently used in arts and crafts. (Aside: we even ran into them at Maker Faire in a FlipBooKit animation.)

Muybridge Carousel

Amanda found a file on thingiverse of outlines of the Muybridge horses that were intended for use for laser cutting (for animation purposes). She remixed it for use with the Eggbot to make the horses go around the egg and published her Muybridge Carousel design on thingiverse.

Muybridge Carousel Trio

Photo by Amanda Geyer

Evil Mad Scientist Valentines, 2014 Edition

Lo Res Valentines

Last year we released a set of six equation-heavy ”Download and Print” cards for Valentine’s day.  This year, we’re doubling the size of the collection (to twelve!) by adding six more cards, this time heavy in symbols, not equations:

valentines

You turn me on” …with an SPST switch.

valentines

I can hardly resist you.

There is room for a future superconductivity joke here, involving a phrase like “I can’t resist you (below a certain temperature).

valentines

You can download the full set — including the 2013 cards — here, a 500 kB pdf document.

As with last year’s set, print them out on (or otherwise affix to) card stock, and [some steps omitted] enjoy the resulting lifelong romance.

 

A Compendium of Watercolor Paint Pan Palettes

sargent art paint palette

As part of the documentation for the WaterColorBot project, we’ve put together a compendium of information about commonly available watercolor paint palette sets.  For each of the sets, we’ve tested to see how well they work in the WaterColorBot— in terms of physical size, color order, paint quality, brush quality, and so forth.

You can find the complete list on our documentation wiki site, here.

Citizen Science: How Big is a Bird Egg?

emu egg in ostrich eggbot

While talking about egg sizes in the context of the Eggbot project, we realized that while we have access to a few samples, we do not have a good understanding of the normal variation in the sizes of various bird eggs.

The sizes of chicken eggs are well understood and well regulated, but for other types of bird eggs (like the emu egg above) the sizes are not necessarily so standard. If you have access to other types of eggs or eggshells, we’d like your help in gathering data about the size and variation in these other types of eggs.

We’ve set up a survey form to collect egg size data and we plan to post about our results once we have collected enough data.

Thank you!