Moving Rainbow Bill of Materials

We encourage everyone to purchase one device from (or make a donation to) the fine people at Arduino.org and Arudino.cc. It is their efforts that have produced the popular tools that we use to program our chips.

We also want to thank the people at Adafruit for writing the NeoPixel driver libraries.

Here are some of the parts you can purchase on-line:

LED Strips

All the addressible LED strips are based on the very popular WS-2812B chip. The tape comes in 30, 60 or 144 LEDs per meter, in white and black background and with and without water-resistent silicon wrapper. For the kits I use the 60 LEDs per meter and a black background.

NeoPixels from Adafruit The prices on the Adafruit site have been about $25/meter without shipping.

Generic WS-2812B Addressable LED Strip
The prices are about $5/meter for the 60 LEDs per meter. They tend to take about two weeks to arrive from China.

My standard kits use 1 meter strips with 60 pixels. If budgets are a problem 30 pixels strips will work, just remember to change the headers in the sample code.

Arduino Nano

I prefer the low-cost Arduino Nano processors that you can purchase from China for around $3. Although you must download a free driver to get the Nanos to work, when you purchase 20 kits at a time the price difference add up. Arduino Nano on Arduino.cc

To find the best price I usually go to EBay.com and search for "Arduino Nano V3.0". Make sure you do NOT get a "pro mini" versions that have no USB conector. Sample Link on E-Bay. The prices as of April 2015 was $2.89 with shipping and it takes about 4 weeks to ship from China.

You can also get a full size Arduino Uno from the Microcenter in St. Louis Park, MN for $9.99 + tax.

USB Cable

USB Cable on E-Bay Make sure you get a connector that matches your Arduino. Most of the Nano's use a "Mini-B" connector.

Solderless Breadboards

I usually include the 400 tie point solderless breadboard in the kits. It is enough room for most projects and it fits in the standard box. You can get them on E-Bay for around $2. Solderless Breadboards on EBay

Boxes

I have tried dozens of boxes and the one that students like the most are the clear polystyrene boxes that are 8-1/4" long. You can get these at The Continer Store for $3.99 earch. If you search for "Shallow Narrow Stackable Rectangle Clear" you will find them. The link is here The dimensions are. 8-1/4" x 3-1/2" x 1-1/2" h. Note that this box is an ideal size for students to put in their backbacks, take to school and show their friends. This is critical for the "viral" nature of the these kits. The more other kids see them the more they show their friends.

One other lower-cost option is to just get the plastic "shoe box" containers from a local retailer.
These are larger, not as clear but lower cost. I can usually find them for under $1.00.

Other students have found left-over containers at places like the dollar store. Look for clear versions that you can drill holes into.

Other Optional Parts

Many of our kits also have a power switch, a rest button and a "mode selection" dial. Hooking these up is a bit more challenging,since there are 7 additional wires used.

On-off switch

I like to use a Mini 2-position toggle switch for about 30 cents each. 10 SPST Toggle Switchs You can get 10 for $3.24 with shipping. This is about 1/3 of price of other switches.

Rotery Encoder Mode Selector

Many of our kits have several "modes" that students can program. Each mode displays a different pattern. Rotery Encoder Push Button Switch You can get 10 of them for around $5.00

Momentary Push Buttons

These buttons can be used to change modes or cycle through different color patterns. Momentary Push Buttons I found 10 fo them for $3.67 with shipping.

Sample Price Estimator Worksheet

I have created a sample spreadsheet you can use to estimate the per-kit costs. You can find a link to it here:

Price Estimator Worksheet

The current total is around $14.00 for all the parts when purchased in quantity 10.

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