Quick update to last week’s post about the doorbell project. I’ve now squeezed in into an Altoids tin (surely everybody’s favourite project box), complete with a little hole for the radio antenna. It’s now permanently connected to the Mac Mini in the living room, meaning roo_house on Twitter now makes an update (“There’s somebody at the door”) when the bell is pushed.
Why use Twitter for this, out of interest? I was thinking of using a combination of Spread and Jabber for those kinds of things myself – a Spread group running over my private network for events to be notified to and things to subscribe to, one of which would be a Jabber bot that notifies a select list of people (Wife and I) of interesting events.
Mainly, this is because I feel nervous about (a) making stuff about my house’s workings public, for security reasons (you should see the security system I’m designing… but, then I’d have to kill you) and (b) relying on a third-party online free thing like Twitter for anything important rather than just fun!
I use Twitter to expose this (so far, more outputs coming soon) partly because Twitter already fits nicely into my life. It very easy to get things sent to IM and/or SMS. I’d only expose the just-for-fun stuff of course, and I’m not planning to publish any ultra sensitive stuff in a channel which is both public and (let’s be honest) prone to random failure. :-)
There is a pub/sub messaging system inside my house already (using the MQTT protocol, but I’m also thinking about Jabber/XMPP too). This external exposure of certain bits of it is a subset of that of course.
Yeah, similarly, I’m taking the approach that internal telemetry is cheap and not for direct human consumption – regular updates from sensors and stuff like that would be welcome there, but the ->Jabber gateway would do ‘smart’ analysis of the data and convert it into more interesting streams of pertinent messages when things change or exceed limits.
But yeah, Jabber can do the IM stuff, and SMS is easy too (see http://www.clickatell.com/; sign up, buy some credit, then invoke their SMTP or HTTP APIs); those are what I’m currently using for event notification in my external systems. Finally wiring the house properly will take a bit longer, though – we’ve only just got the floor back in! :-)
“internal telemetry is cheap and not for direct human consumption – regular updates from sensors and stuff like that would be welcome there, but the ->Jabber gateway would do ‘smart’ analysis of the data and convert it into more interesting streams of pertinent messages when things change or exceed limits”.
Exactly. Well put.
I’ll take a look at Clickatell too. Sounds handy.
Update: it’s been offline for a while; I broke the antenna. I now have a new soldering iron, so I shall fix it soon. I might use a longer piece of wire to see if I can improve the range and reliability too.
Hi Roo, I went out and purchased a door bell today and had a play with it on my arduino. The circuit board in my doorbell looks exactly the same as yours. Although I just seem to get constant noise from the white cable. Did you swap your doorbell to one similar to Nick’s or have you had this model working with the sketch you included in the previous doorbell post?
Hi Chris. No, I didn’t get one like Nick, this one works for me. One of the two white cables is the radio arial (but that one should be obvious, as it’s disconnected). Strange that you’re not getting the same results. Maybe it’s a different make but confusingly similar? My peripheral memory tells me mine was a Byron SX81R.
Hi Roo
Have the same doorbell, just done the same thing: connected it up to my Arduino. Do you know how much current it draws without a speaker connected?
i.e. the way you have it, connected to 3v3, ground and analog0?
Wondering if I need a resistor.
Thanks
Hi Dan
I’m afraid I can’t remember (and it has been offline since we moved house a while ago). I think I was relying on the internal pullup resistors in the Arduino, though I have no idea if I checked whether that was a particularly safe or sane thing to do.
Do you have a multi-meter? Let us know how you get on.
Good luck!