Let's make DIY littleBits! For original circuits, visit littleBits.cc
*Added since initial publication: light trigger* I change the original circuits based on parts availability and my own preferences and ability. I volunteer for the Fresh Air Fund, and my hope is that I can learn enough to offer a free afternoon workshop this summer for the children who visit my town just 45 minutes north of NYC.
The connection method I currently use between bits involves 3 header pins on both the left and right sides and female to female jumper wires. There is no kanban mechanism to prevent miswiring, so the user must be careful when connecting DIY bits. One idea is to use alternating male and female pins on alternating sides with male to female color coded jumper wires (red=+VCC, green=signal, black = GND). If you decide do use alternating male and female pins and jumpers, then the male header pins should be on the left of the bits; this is to prevent dangling live male jumper wires from crossing each other and creating a short circuit.
PARTS: If not stated in each individual step, you will need solder, hot glue, 22 gauge stranded insulated wires, perfboard, male (maybe also female as you like) pins, jumper wires, heat shrink tubing (electrical tape is ugly but will suffice), and a method for labeling your DIY bits. Many bits require an op amp chip, which can get pricey if you are buying them individually from the store. I recommend buying larger quantities of chips from www.digikey.com. The Digikey part number for the LM741 op amp chip is LM741CNNS/NOPB-ND ; at publication time, I was able to buy this chip for $0.70. For labeling bits, I use #6 plastic from the recycling bin (also sold as shrink film by www.digikey.com.
Tools required include wire stripper, soldering gun, helping hands, needle nose plyers, hot glue gun, and a method for cutting perfboard (I scored it with a sharp knife and snapped it over a straight edge ruler, but some prefer to use a dremel). The most important tool is a good book; I recommend Timer, Op Amp & Optoelectronic Circuits & Projects by Forrest M. Mims III http://www.forrestmims.com/engineers_mini_noteboo...
The first thing we need is POWER!!! The original "p1 power" circuit requires a power regulator that Radio Shack does not sell, so instead I bought the 5V regulator which is most commonly used by hobbyists - the LM7805.
1) 9V battery
2) 9V battery snap with red and black wires
3) Perf board cut to 9 x 12 full holes
5) Capacitors: 0.1uF ceramic disk (code 104), 1.0uF (maybe dipped tantalum), 10uF electrolytic ... Pay attention to polarity and substitute as risk will allow.
6) Resistor: one 330 ohm
7) one small red LED
8) spdt slide switch - a single throw switch may suffice
9) 3 header pins
10) 3 jumper wires
1) Breadboard and test that V and S output 5V.
2) Arrange on perfboard & solder.
3) Test that V and S output 5V.
4) Hot glue any weak connections, including the output pins to the perfboard. I hot glued this bit to a blue 4x6 lego plate, as power is coded blue in littleBits.
5) Great job! You can use this bit to power any projects that require 5V.