Hi
This is my first post to this forum, and the first time I've done anything with the Arduino. I have a little experience with electronics, having built a few projects using the Parallax Propellor.
I have built a DMX receiver using a Propellor chip and I was going to use this to drive several TLC5940 LED drivers. The idea was to have the Propellor in a 'hub' connected to several 'tiles', each containing a TLC chip to drive 16 LEDs. Unfortunately while the system worked perfectly when joined with a very short cable, as soon as I used a longer cable all kinds of interference was introduced which made the system unusable. It was suggested on the Parallax forum that I use line drivers to boost the signal level so it would work over long cable distances, but the chips worked out to be quite expensive.
While Googling for ideas I came across the TLC5940 project on this website. After a little research I was shocked to discover that one Atmel CPU and associated parts would cost less than the 5-way serial line-driver setup I was considering using! Now I want to build my tiles with an Atmel cpu and a TLC chip, and use a serial interface to control each LEDs brightness. This will allow me to use anything that can generate a serial string to control the tiles.
I want to use RS485-differential signalling to talk to my tiles as this allows very long cables (its used for DMX as well). I only need to send data to them, not receive anything back again. I am currently in the process of breadboarding my first Arduino using the schematics and instructions from this site. The schematics use a 7404N hex inverter chip in the serial interface. My question is this : will I need the 7404N chip when I implement the RS485 interface, or can I just connect an RS485 chip such as the MAX487 directly to the processor?