I'm an embedded product designer with over 30yrs experience and I'd like to try my hand at an affordable & expandable HA / HVAC controller. I'd like to keep the MSRP in the $200 range.

The following is a rough draft of the hardware & peripherals, if I've missed something you'd like to see added (or even discarded) please comment.

PIC18F87J60 microcontroller with Ethernet

6 Relays (2 NC/NO, 4 NO, jumpers / labels for GP or HVAC RE2-7)
4Opto Inputs with interrupts
1RS485 or RS232 (RTS / CTS could be reassigned as a SW TX / RX)
1RS485 or XBee / XBee Pro (Zigbee?)
1 SPI (RTCC with battery backup, 128k EEPROM html, ajax)
1Ethernet 10/100
1433MHz RX
1433MHz TX
1LM35 temperature sensor (freeze sensor)

The yet unnamed suggestions? controller connects to your LAN and could be controlled by anything with a web browser.

When this kit is done I plan on doing a 433 / 315MHz temperature / humidity sender to replace the traditional thermostat on your wall.

I'm trying to gather options, ideas before starting the PCB artwork.