An arduino mega, 16 rgb encoders and 16 rgb leds

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi,

I'm hoping to get 16 rotary encoders with push buttons and 16 rgb leds chatting happily to my arduino mega.

The plans is to use two R-2R resistor networks two interface the buttons, two M451 chips to drive the leds and 4 MCP23016 chips to multiplex the rotaries.

Do you think this is plausible? I know speed could be an issue with regards to reading the rotaries. Are there any other problems that could be prevent this from working.

Any advice would be very much appreciated. I'm very new to all this.

2

MCP23016 chips to multiplex the rotaries.

Problem with that chip is that it is I2C and so is a bit slow for the interrupt driven application. You are better off using the MCP23S17 which has a SPI interface which will be much faster. The features of the rest of the chip are very similar and you can address drive up to 8 of them on the SPI bus.