simple encoder/decoder I/O multiplexer solution

[Simon]

I am devising a unit. I have one button and 4 LED's at present. So I need 6 wires. Is there a simple chip and/or protocol out there that con be used instead of 6 individual hard wires? The cable may be as long as 10m between control panel and system.

LIN bus time?

[mikerj]

Sounds an ideal application for one of the numerous I2C I/O expander ICs. 

[FrankBuss]

Maybe use 1-wire with a DS2408. It is not a cheap chip, but you could implement it with 2 wires. 1-wire has been tested up to 300 meter. Don't use I2C, anything longer than some cm is asking for trouble.

[Simon]

I thought I2C meant IC to IC comms, ie on the same PCB. I do have the option of the ATmega3208 I am already using that has built in LIN

[Buriedcode]

LINbus seems overkill for a few LEDs... why not just a small MCU running very slow serial?  Or even MIDI? 10m would be pushing TTL level serial but you could always try it with the cable you have.  There's always the simple PPM/PWM used in cheap RF remotes although given you have an input as well you could jsut use that for the LED's, and a single wire for the button, that way comms is oneway.

[Simon]

LIN bus works with serial hardware.

[SiliconWizard]

I would keep it simple and use an UART-based communication and RS-485 transceivers. That will allow you to use much longer cables than 10m and is dead simple.

[Simon]

i think I will leave this aspect alone and just use the 6 wires for now. We use CAN as a company and I am planning an optional CAN board attachment for this project so I'll just make it an excuse to start learning CAN.