hi mark! some points to your project: rs485: you can add any number of receivers, it's just convention to make the adress 8 bit long. if you don't use prefabricatd receivers - as i understood, you build the receivers yourself - so you can treat rs485 as rs323 and implement your own protocol. example: use 7 bit per byte and 1 bit for packet start (= bit 7 of first byte is 1, on all other it's 0). the the remaining bits 0-6 as payload. adress is byte 0 and byte 1 (14 bit), brigthness (8 bit each) for the 3 colors are stored in the remaining 4 bytes (7 bit each, bit 7=0). optimize it, it's up to you :-) when you build the circuit you must pay attention that you have a current-loop. you must source enough power for all receivers, ex: 10µA * 1500 = 15 mA. source must be minimum 10th, so 150mA. as i read it, each of your leds has a receiver. as the receivers never talk back, it might be enough to take a rs232 and a impedance converter - so any board will do (fox board, pc104 ...). and you can transmit slowly, 9600 baud will do. ... maybe you should use an atmega1xx, maybe the butterfly-evaluation board ? :-) n. -- Mag. Dr. Nikolaus Klepp EDV Dienstleistungen Beratung, Service, Programmierung Einnehmerstraße 14 A-4810 Gmunden Tel.: +43 650 82 11 724 email: dr.klepp@gmx.at www: www.samhain.at UID: ATU51611304
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