Holiday Projects?

Last day this year at work and have been thinking about what to build over the two weeks of xmas. I have a house I built from the ground up so lots of technology deployed. However, I failed (not through choice) to get my underfloor heating under the control of a server. The UFH has 16 water circuits, split across two floors, with each circuit having its own Heatmiser thermostat. Each thermostat has CAT5 cable back to a wiring centre, providing power (12V), relay output for the valve actuators, and, a RS-485 bus. So, I’ve got another Imp, an RS485 interface chip and and LCD display and I’m going to challenge myself with building a server that can talk (read/write) to all 16 thermostats and present say an HTTP interface.

Have seen a few discussion about RS485, blobs etc, which will be a great help as this will be new territory beyond the garage project.

Anyone else embarking on anything over the holiday period?

Suffice to say I’m extremely jealous of your setup.

We moved into a new house over the summer, and I’m making a replacement hot water / central heating programmer using an Imp. Plus a corresponding iOS app. I’ve also just received PCBs form OSHPark for a network of room temp monitors, that will work with the programmer to decide when to turn on the heating (no thermostat currently).

When considering what to build over xmas, I did consider building a new room thermostat. So many makes out there, but they all look so ugly. The basic industry design principle seems to be; plastic case and an LCD display. I’ve been thinking more; glass plate, touch sensitive, and lighting (display?) behind, with ability to detect presence, temperature and humidity. However, then I thought… Oh I would have to build 16 of these. So I decided to leave them in place for now and build a single interface to the existing ones.

My hot water/central heating has a few ZWave components in it as well to control the towel radiators.

How are you going to link your z-wave universe to the impyverse?

I was looking at z-wave for my current house renovation but was put off by the cost of the hub :frowning:

I have a Fibaro hub, but it’s a little retarded when it comes to speaking with non-ZWave devices. However, it seems to support a RESTful interface to other devices. So will work on Imp’ing the thermostats to present that interface and see if the Fibaro hub will play ball.

I’m planning an imp based sprinkler system with web smarts to look at weather history and forecast to decide to water or not.

Should be fun! And it will get rid of my circa 1991 sprinkler controller that I hate with a passion.

@302tt What will Imp activate to start the sprinkler ? Also interested in where you’ll get your weather/forecast info from.

@DaveDotNet is an interesting one. There was a kickstarter project recently, the Lono sprinkler system, which enough people thought looked good!

DaveDotNetDaveDotNet 4:30AM @302tt What will Imp activate to start the sprinkler ? Also interested in where you'll get your weather/forecast info from.

The Imp device is just 4 relays to send 24vAC to each zone sprinkler solenoid. For the weather I have not started the coding side yet, but I was thinking an agent to talk to a weather API

@opb does look good. First 1,000 API requests/day are free (I always like that), and it’s also JSON, so that should make it easy to handle. Will definitely look into that.

I have a 220 volt sprinkler pump that pumps canal water for irrigation and is controlled from a circuit breaker, kind of primitive. The attached PDF shows a pump relay and I was looking for some ideas and suggestions on on making it imp enabled.

Though it seems silly, another relay is going to be the best idea. The main coil is 24vac and switching that electronically is a pain.

Hugo is right, use a “slave relay” to control your 24VAC relay. Another reason to do this is because the manufacturer has already designed the correct relay with their product (voltage, load-rating, arc-rating, etc). You won’t be affecting the safety or performance of their components, you’ll merely be putting their 24AC to their relay by using your own low-voltage 5VDC relay.

PS… I really like those Clare 5VDC Relays. They are constructed in a standard 14-pin DIP package, so they fit nicely on a standard perf-board. Also, you can get USB wall-wart power supplies that are 120-220VAC (universal).