Home Automata

After a long time with nothing much happening, I'm now working on my home automation pages again.

Paul Harrison, Joshua Samuel and I have discussed home automation several times, and we discussed putting a web page for the various little bits we make.

My current system is using Dallas Semiconductor's 1-wire protocol for sensing, and the bulk of my relays are controlled with an i2c bus with pcf8574 port expanders.

• Controller
• Light
• Clap control
• Heating
• Computer controlled Power supply and UPS
• Computer controlled analogue mixer

Any system which is to do more than replace a switch and timer is going to need some environment measuring devices. I am working on several input devices:

• Solid state yes/no water level sensor.
• Solid state digital water level sensor.
• Temperature sensor based on the digital temperature sensors (DS1624).
• Presure sensor, probably using a silicon pressure sensor.
• Humidity sensor - using a crystaline sensor.
• Soil wetness-ometer - conductivity.
• Ph meter - need to get a decent commercial meter for this.
• Lux meter - could use a photo diode, but calibration is a big issue.