Control 8840 Thermostats

aldous

Hi,

I am having some problem to control the OPTStat 8840 and hoping to find some answer here, please.

I am using the modules downloaded from AMX. I am able to change the Heat/Cool set point setting for day time. However, When I set the thermostat to night time and then, send a command to change the set points, it's still changing the day time setting only. What can I do to change the night time set point from the TP and display it on the TP?

Thanks very much,
Aldous

DHawthorne

aldous wrote:

Hi,

I am having some problem to control the OPTStat 8840 and hoping to find some answer here, please.

I am using the modules downloaded from AMX. I am able to change the Heat/Cool set point setting for day time. However, When I set the thermostat to night time and then, send a command to change the set points, it's still changing the day time setting only. What can I do to change the night time set point from the TP and display it on the TP?

Thanks very much,
Aldous

I have always resorted to my own code for things like this. The protocol for these thermostats does not have a command to set "day" and "night" setpoints. They will only set the current setpoints. The day and night settings are strictly local to the thermostat. So, I disregard them. I make my own timers, store my settings on the master, and send the setpoint changes when the time comes around. This also allows me to use them just like any $20 Home Depot programmable thermostat, and provide morning, day, evening and night settings, as well as different settings for different days in the week. I never understood why the provided modules didn't have this kind of functionality; a remote control for a thermostat is better than running around the house to adjust the temperatures, but setback timers are pretty basic. But to do it, you have to roll your own.

NMarkRoberts

Rolling your own (and sniffing the strings)

Somewhat off-topic...

Is this what others have experienced? Every time you rely on the smarts in the box or in the standard module they let you down, and it takes a week to realise it because you start with the easy stuff, and it's only when you get to the difficult stuff that you realise it's no good, and you just keep plugging away because of the good old "sunk cost" fallacy.

So you waste a week and then you have to write the code for all the smarts that you hoped you could just borrow, and of course that takes another week.

Examples of not-clever-enough "smarts in the box" that come immediately to mind frm personal experience:

Camera Presets
FM Tuner frequencies
VCR recording timers
Every standard module provided without source code that I have ever tried to use

However I do concede that the week you spend nutting out the unsmart box/module is very useful because by the time you write it yourself you know exactly what you need to write. And while the module may not do everything you want, you can watch the strings going to and fro to see how its programmer solved the other problems.

So here is the strategy I will try to use next time:

Whack in the standard module and fire up the box, sniff the strings, play tunes on the remote, then roll my own.

DHawthorne

Unless it's a simple device (say, a single disc DVD player), I consider AMX provided modules a starting point. Most often, I use the comm module and toss the UI, unless it's really complex (like the MAX UI module). It's rare that you have to entirely toss the provided module; generally, you can just add another module with the functionality you need and run them together.

I wrote my first Viewstat module long before there was anything available from AMX. In fact, it was adapted from code written for an Axcent3. So, when the AMX module had nothing to offer in terms of additional usefulness, I just stuck with mine. But, if I were doing it now, I would use the AMX module to talk to the stats, and just make a seperate timer module to talk to that. I wouldn't do it from scratch.