I was recently amused to see a smart home feature in a television advertisement for Admiral Insurance. In that advertisement George the householder meets The Admiral outside the local bistro and, as the day is set to be warm, decides to turn down his smart heating from his smart phone.

Unfortunately George manages to hit the wrong button on his smartphone and instead of turning off the heating manages to open the garage door.

The opening garage door hits George’s red car, which hits the yellow car, and pushes down the boundary wall onto the road. George witnesses all this as it turns out that the bistro is on the opposite side of the road to his home, so has a go with another button.

George’s second attempt at adjusting the heating is no more successful as he manages to turn the fire sprinklers on which floods the house. Hopefully George has more than just multi-car Insurance.

So, besides amusement, what else might we gain from George’s issues?

1. Firstly, I’ll observe that in my home you can put the whole heating system into summer which disables heating completely (such as in the summer), or vacation which disables the schedules but which continues to heat as necessary to maintain a minimum temperature (such as winter frost protection), or turn off the radiators in individual rooms, or turn down the temperature until such time as the schedule turns them back up.
2. You don’t always get many characters to label a device or scene, but it does need to be clear what function will be achieved by pushing the button. (I find rules particularly frustrating in the Apple Home app as you can’t name rules and it becomes hard to distinguish between them, although Eve’s app which edits the same rules does allow naming and is much clearer for programming rules generally. The WIFIPLUG app also allows the button to be customised with a photograph of the appliance which is quite neat.)
3. Devices like garage door openers can be linked to safety interlocks. I don’t have one myself but you can have a light beam, for example, across the doorway so you can’t close the door when obstructed by a car. I haven’t come across an interlock which ensures that the car is far enough from the door to allow opening, although in reality I think that a domestic car door opener would likely stop when it touched the car, detect an over torque / current condition, and then automatically reverse.
4. Finally I think that smart home systems would benefit from a configurable ‘Are you sure?’ question to double-check that the user really wanted to perform some potentially damaging action such as open or unlock a door.

(Tapping the Admiral is a nautical expression referring to being prepared to drink anything alcoholic rather than be without a drink, notably including drinking the contents of the barrel in which the body of a recently deceased and pickled admiral was being carried.)

The other day I was involved in a discussion about how Eve Motions work. Some participants were concerned that Eve Motions always show motion for just the configured ‘on’ time and then go off until retriggered. The effect of this would be that if, for example, you were controlling a light, that light would always go off briefly before being triggered again which would be annoying and inconvenient.

However, this log (above) from my own lounge Motion, that is used to curtail the heating when the room is unused, shows ‘on’ events often being much longer that the 30 minutes that I have set (see below).  

My understanding therefore is that the Eve Motions trigger on first movement and continue to report ‘Motion’ until the delay time after motion ends.  I can’t otherwise explain Motion events that last for variable periods and, in some cases, multiple hours.

At the last count my smart home system had eighteen rules, so I thought that some description might be appreciated. Those 18 rules run a combination of (i) a multi-zone heating system, (ii) warnings related to windows left open, and (iii) some interaction between the two where local radiators are disabled if a window is left open.

Regular readings will recall that our central heating is run by Apple HomeKit giving multiple zones with independent time and temperature schedules, we also monitor key windows to warn if they have been left open, and have some interaction between windows and radiators so local radiators are disabled while a window is left open.  Generally all of this works very well, but occasionally we find that the state of the window warning lamp is inconsistent with the physical position of the windows, or the boiler runs unexpectedly overnight (although it only heats the central core of hall, stairs and landing).  I suspect that the cause is intermittent lack of communication between the hubs and smart devices such the the hub misses the shut down of the last radiator valve at night, the last window to be closed, or the first to open.  Control rules are all triggered by changes of state, and if the change of state is missed then you’re sunk.

It occurred to me that what is required is a periodic check on the status of the imputs and appropriate changes to the outputs even if the change of state that should have triggered the rule was missed – I think of this as a watchdog.  In the ideal world it shouldn’t be needed but periodically it will correct the status of an output.

You could of course program multiple time-based triggers into every rule (remember that a rule is if any trigger and all conditions then set scenes), but this is time-consuming and far from elegant.

Elagto’s Eve app, which I prefer over Apple’s own Home app for writing rules, does offer a recurring timer function, but it only enables a scene directly and cannot itself be part of a trigger or condition in a wider rule.

My solution is to find a device for which I can both set and read the status.  In my case an Eve Energy which I can both turn on and then test to see if it is turned on.

This was handled as follows:

1. Create two new scenes, one of which just turns the device on, and the other just turns it off.
2. Create two new recurring timers; for me one sets the on scene on the hour, and every five minutes subsequently, and the other sets the off scene at two minutes past the hour and every five minutes subsequently.
3. The device should now be cycling on and off continuously – two minutes on and three minutes off.
4. Next I’ll test the on transitions as part of a series of rules.
5. Each rule to be modified may need two steps of modification.  Firstly the existing triggers may need to be replicated as conditions – so for example an ‘at sunrise’ trigger may be to be replicated as conditions ‘after sunrise’ and ‘before sunset’ given that this rule will be retested throughout the day.  Secondly an extra trigger is added for if my watchdog turns on.
6. The resulting rule should still work in the original manner if the ‘at sunrise’ trigger is detected, but if not within minutes (and every five minutes subsequently) the watchdog will trigger another evaluation of the rule.

My expectation is that this will improve the robustness of my system operation once I’ve changed all my rules suitably.

Of the course of the last year or so I’ve gradually created a smart home system with in the teens of components as follows:

• • 8 Eve Thermos (eTRVs) which replace the standard TRVs on the radiators.  These eTRVs are programmable for both temperature and schedule, replacing the previous central heating timer at home level with multiple timers at room level effectively creating a multi zone system.
  • 3 Eve Window switches which detect open windows.  These illuminate a warning lamp and/or disable heating of that room while the window is open.
  • 2 non-Eve smart bulbs. Both of these operate on a dusk-to-dawn schedule while one also illuminates in a colour when any of the 3 monitored windows is open.
  • 2 Eve Motions.  One of these adjusts the lounge heating in the evening based on room occupancy so that the heating is disabled earlier in the evening if the room is not occupied.  The other is as yet uninstalled.
  • 1 Eve Energy which is a remote-controlled outlet that turns the gas boiler on or off based on heating demand from the eTRVs and a couple of rules.
  • 1 Apple TV box which acts as a home hub for monitoring the devices and running multiple rules which operate lamps and outlets based on input status.  Currently input is taken from valves, windows, motion, and external dusk/dawn signals and outputs sent to other valves, lamps, and socket outlet.

At the moment I tend to add a new device each month – if I can think of a useful function that it can perform.