[OpenTRV-interest] getting hands on some valves

[Damon Hart-Davis]

> On 28 Nov 2016, at 08:13, Simon Hobson <linux at thehobsons.co.uk> wrote:
> 
> Kairos <kairosmedia at swissmail.org> wrote:
> 
>> -- What exactly "open" in "OpenTRV" means..
> 
> I think it means that both the hardware and software are "open" - as in, not closed, not proprietary, not covered by "if you try to reverse engineer it we'll sue you to oblivion" clauses. At least, during development, all the hardware schematics and code were openly available so people could tinker with it.
> Don't know how that holds up when they get into the real world of having to make money from it !
> 
> As for using your own customer control system, I think there's been mention of it in this list.
> As I recall, there are a couple of problem you need to watch out for.
> Firstly, there' no back channel by default - for the simple reason that making it secure isn't trivial so the easy way to securing it is to not have it.
> If you do enable a back channel, the low power radio only wakes up something like once ever 2 minutes - thus you can only send a new command every 2 minutes. This means you couldn't use it for real-time control (such as setting the vavle position), only for something like setting the setpoint for the valve to follow.

All correct (though our TX interval is currently 4 minutes).

Rgds

Damon