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shiftbrite_shield

Introduction

ASCII The ShiftBrite Shield is a convenient way to attach ShiftBrites and power to a standard Arduino controller. It has a screw clamp terminal for power connections, a right angle header for SPI control of ShiftBrites, pass-through female headers (optional), and a large prototyping area for custom circuitry.

Features

Type: Arduino Shield
Function: Supply power and control to ShiftBrites
Works with: ShiftBrites, MegaBrites, ShiftBars
Fits: Arduino Diecimila, Duemilanove, Seeeduino, etc.
Power Supply: 5.5V to 12V DC (ShiftBrite Header)
5V (from Arduino)
Pin Usage: Digital 9, 10, 11, 13; VIN
Inputs: Power via screw clamp terminals
Outputs: SPI ShiftBrite chain
Other features: Passthrough female headers, prototyping area

Power Connections

shiftbrite_shield_hookup.jpg The + and - connections are accessed through the screw clamp terminal on the ShiftBrite Shield. These power terminals are directly connected to the V+ and GND on the ShiftBrite chain connector. The direct connection will minimize any problems that could be caused by inline diodes or thin power traces on the Arduino board, since a ShiftBrite chain can easily draw several amps. The power connector can also supply power to the Arduino if the PWR jumper is closed.

In the photo (left) the red power wire is positive (+) and the black wire is negative (-).

ShiftBrite Connection

The photo (above) shows a six-pin cable connected to the ShiftBrite header on the shield. The V+ and GND wires should always be connected to the matching pins on the first ShiftBrite. If the ShiftBrite is connected backwards, the odds are very high that it could be destroyed.

PWR Jumper

PWR Open PWR Closed

The PWR jumper connects the ShiftBrite power supply to the Arduino VIN terminal. This means that you can pass the ShiftBrite power supply through the built-in voltage regulator on the Arduino board, requiring only one power supply for the entire Arduino-ShiftBrite system. To a lesser degree, it also means that power can be drawn from the Arduino power input terminal, and used to power ShiftBrites. However, this should only be used for a few ShiftBrites; all the power is passing through the Arduino protection diode and the power traces are usually small. The jumper itself is also not intended to carry several hundred milliamps, like a string of ShiftBrites is easily cable of draining. The PWR jumper also does not allow ShiftBrites to be powered from USB 5V power. You should not try to run ShiftBrites from USB anyway, since they will likely draw more power than the port is capable of supplying. ShiftBrites also need a bit higher voltage than 5V to correctly supply their internal regulator, and prevent signal corruption along the chain.

/home/macetec/public_html/docs/data/pages/shiftbrite_shield.txt · Last modified: 2012/01/05 17:04 by macegr