Anyone seen the latest news about Google Nest?
Previously, I was going to buy 5 or 6 Nests for our new home. I already have one, which I have enjoyed for the last few years. But now - no way! I don't like the direction that consumer HA is going anyway, so let's make our own clone of Nest!
So, who is up for making a DIY clone of Nest? I already have this UI clone operational in my NR dashboard:
The control side of things are easy for me: a SONOFF near the boiler and a rotary controller / display in the wall. I plan to use my Fleetwood controller in each room. And obviously this requires multiple temperature sensors housed in some fancy wall-mounted box.
But the tricky bit for me is the software. Obvs I want to use Node-RED for all the logic. Can someone join me?
Suggested spec, in order of priority:
- Phase 1: time switch. Some kind of time / temperature programming interface in NR Dashboard.
- Phase 2: comfort. Silently break-out out of timer mode with a temperature adjustment input. (i.e. "walk in room, turn up the temp"). Recommence time/temp mode at next timer event, unless that timer event is in the next hour or two, in which case delay it. Similar to "boost" on an old thermostat, but nicer.
- Phase 3: intelligence. By default, our system will result in high heating bills and a feeling that it's just not as "clever" at predicting the right temp as Nest. It therefore must work hard in the background to reduce heating bills without sacrificing comfort. I have broken down the problem below, but whilst we are implementing this problem, we have to live with the system. So I propose first implementing some kind of slider that allows us to adjust between "try to reduce bills" and "try to keep us warm".
- Phase 4: reporting. Seems a shame to leave this until the end, perhaps the key to developing this system is in the monitoring, to allow tweaking the algorithms, configs, etc. But reporting is definitely useful for the user. I love Nest's email reports like "you used 14 hours of heating this month", comparing to last month, same time last year, etc.
Notes on Phase 3: Making the system intelligent (economy and comfort)
- The first quick win is to use location sensing to enable and disable "away". But even this is difficult. I wonder, does Nest somehow manage to predict you are coming home? Or does it just know when you are near home? The obvious difficulty here is if you work every day very near the home, Nest will assume you are home. How do we define "away"? Does the definition change over time, e.g. if my workplace is 50 yards away and I set myself as away a few time, does it learn this? What about the idea of a "confidence" level, to prevent flip-flopping when you nip out to the shops, or even spend 4 hours in the garden? Should this confidence level depend on time of day, how long you are usually gone for? How far away you are? What about multiple users? Am I over-complicating this?
- Also requires ability to set the away temperature, e.g. 15*C. Should this change depending on the confidence level?
- Sense location using OwnTracks? Is this the best option?
- Using room presence sensing to keep existing set temp regardless of timer events
- Economy AND Comfort
- Using location sensing to spot patterns and quietly adjust the timer events that you thought you set up correctly but didn't
- Learn from user adjustment (i.e. the manual "tweak" of room temp): if this happens often around the same time every day, every Saturday, or whatever, then silently adjust the time/temp program
As always chaps and chappesses, I'd love to hear your thoughts.