I'm running 7 7-segment displays (Sparkfun Serial) diplaying the same information (this is for a piece of music theatre in which each performers is looking a clock with an output from Max/MSP). The power is running from an external source (DC5V 1500mA), and is fine, but I'm having cable length issues with the RX output from the arduino. When I get to about my 5th counter, the RX signal becomes too weak.
Therefore, I need to boost the RX signal. I have been recommended to use a transistor to boost the signal. http://www.maplin.co.uk/Module.aspx?ModuleNo=32952&OrderCode=UL36P I'm going to try the 2N5551 on this page, running inline on the positive line, with the collector pin on the power supply side, emitter pin on the side going to the 7-segments, and the gate pin attached to the Arduino RX.
Does that sound like a good idea? If anybody could help me in this I would be most grateful - I am pretty bad at all of this stuff, and feel a bit overwhelmed and in over my head.