The main feature of MisterHouse that sets it apart from other home automation systems is the ability to customize practically every aspect of the system.  The following example is a perfect demonstration of this.

I recently purchased a whole house fan, basically a giant fan that sucks hot air out from the highest point in my house. They are great if you live in a climate with cool nights.

The controls for my fan were very basic, an on/off switch and a two-speed setting.

With Misterhouse, I created an “auto” mode which will only turn on the fan if both the indoor temperature is above a defined threshold and the outdoor temperature is 5 degrees below the indoor temperature.

This is how I did it.

Starting Materials
– A Whole House Fan
– 2 IOLincs, (1 for on/off, 1 for fan speed)
– A MisterHouse enabled indoor temperature sensor (I used my Insteon Thermostat)
– A MisterHouse enabled outdoor temperature sensor (I used data from a neighbor’s weather station through weatherunderground)

I created the following items in my mht file:

GENERIC, house_fan, HVAC|WHF_Group
GENERIC, house_fan_temp, HVAC|WHF_Group
GENERIC, house_fan_setpoint, HVAC|WHF_Group
GENERIC, house_fan_ambient, HVAC|WHF_Group
INSTEON_IOLINC, DE.AD.BE:01, whf_main, HVAC
INSTEON_IOLINC, DE.AD.BE:01, whf_speed, HVAC

I also had the following items already setup:

$upstairs_thermo_temp #the temperature upstairs
$w_temp #the outside temperature

First, I set the available states for my generic objects:

$house_fan->set_states('on', 'off', 'auto');
$house_fan_speed->set_states('high', 'low');
$house_fan_temp->set_states('cooler', 'warmer');

Then I tied my generic items to my Insteon Devices:

$house_fan->tie_event('$whf_main->set("on")', "on");
$house_fan->tie_event('$whf_main->set("off")', "off");
$house_fan_speed->tie_event('$whf_speed->set("on")', "high");
$house_fan_speed->tie_event('$whf_speed->set("off")', "low");

Then I tied my Generic temp item to my Generic setpoint item, and inserted some custom code:

$house_fan_temp->tie_event('house_fan_temp_change($state)');
sub house_fan_temp_change {
	my ($state) = @_;
	if ($state eq "warmer"){
		$house_fan_setpoint->set(int($house_fan_setpoint->state) + 1);
	} elsif ($state eq "cooler") {
		$house_fan_setpoint->set(int($house_fan_setpoint->state) - 1);
	}
}

By doing this, I can have a nice cooler and warmer button in the web panel.

Finally, every minute I check to see if the device is in “auto” mode and whether or not it should turn on:

if ($New_Minute){ 
	if($house_fan->state eq 'auto') {
		if (int($upstairs_thermo_temp->state) > int($house_fan_setpoint->state) &&
		(int($upstairs_thermo_temp->state) - 5) > int($w_temp->state)) {
			if ($whf_main->state eq 'off') {
				::print_log("[a1housefan.pl] Auto: Turning on fan");
				$whf_main->set("on");
			}
		} else {
			if ($whf_main->state eq 'on'){
				::print_log("[a1housefan.pl] Auto: Turning off fan");
				$whf_main->set("off");
			}
		}
	}
}

The result, is a temperature controlled whole house fan.  The image above is a screen shot from my web interface.