Controlling house heating system

My first post on this great forum!

For two weeks ago I did not know anything about Arduino but now I am very excited to get going with my first design...

I am planning to control the heating system in the garage that is located some 15m from my house. I will measure temperatures at various locations inside (and one sensor outside) and control the heater based on that information. I will also want to communicate with the system remotely from house. Unfortunately I do not have any wires between the houses so I will need to go wireless.

My initial plan is to use: Mega 2560 board Nuelectronics Datalog shield Xbee or other wireless shield SD memory card to save the data

Does this sound reasonable? Can I connect both datalog- and xbee shields on mega 2560? What other options are there for the wireless link? Any other initial comments?

I think the exhibition area is reserved for showing off stuff not asking for ideas/troubleshooting or anything, but I'm kind of new here so I could be wrong.

Sounds like your idea is very plausible but speaking to the thermostat might be difficult depending on what kind of thermostat it is.

you might have to pull buttons off of it and connect them to arduino pins to simulate button presses, or even connect a servo motor to a dial style thermostat to turn it appropriately.

and the SD card seems unnecessary, with the xbee you could have it communicate to a computer elsewhere (say in the house itself) and have the computer do all the logging/analysis.

Welcome ojniemin,

I'm fairly new here too. Since you didn't go into details about heating system, I'll go a couple of different routes.

If your heating system does not have a thermostat and has a wall plug, you might like something like:

If your heating system as a thermostat, it may just need a relay on a pcb to turn it on and off.

For your wireless, I would recommend looking into Synapse Wireless. They sell RF Engines that are similar in price to XBees. The RF Engines allow you to run code on them, or they can simply be used as a serial replacement like the XBee. You could program the RF Engine to read the different temp sensors and control your heating systems. The advantage they provide me is I don't need an Arduino/Xbee combo at every place I have a sensor or control unit. Synapse site:

For 15m, their non-amplified module will probably work: RF100P86:


There are plenty on breakout boards and shields for the Xbee. I couldn't find a decently priced breakout board for the RF Engine, so I made some:

As bleedscarlet mentioned, you could do the logging on your computer in the house. It doesn't matter which route you take, it can be done on both.

If you want to take the arduino route, I would recommend not using a mega 2560 for this. You could use an Arduino Pro and then an XBee regulated explorer Then the datalogging shield you mentioned.

Good luck with you project!

I've recently moved house and would love to make my own heating control system - including zones and isolation valves. Any designs and circuits are eagerly anticipated.

Thanks for the comment! Some more words about my plan. I have a water based heating system in the garage (pipes in the congrete floor). My plan is not to use thermostats but rather control the water temperature based on the outside temperature. I know there are commercially available systems for this but I want some more 'intelligence' in the control system.

The reason to have an SD card is that my computer is powered off most of the time so a card is preferred. Also, this might evolve to include even a house alarm, which should work even when the mains are off.

I will look at the different wireless options. The Synapse is definitely interesting.

The reason I am inclined to using Mega is the amount of I/O. If I want this to serve as an alarm as well then I will need a lot of sensors connected. Was your recommendation a price issues or is there something else I missed?


My recommendation against the mega is two parts. One is price, the second is certain shield comparability. I didn't look closely enough at the data logging shield you mentioned. The SPI pins on a regular arduino are pins 10-13 and the ISP header. On the mega, they are 50-53 and the ISP header. Thankfully the ISP header is in the same place on both boards. You will have to check the shield to see if it has the ISP header so you can use it. Also on the mega, the I2C pins are moved. Typically it is not a big deal to run the wires. It is just something to keep in mind. (I2C would be used for RTC or other devices)

If you need all those pins, go for it. Otherwise there are a lot of other boards that might have something to give you a jump start.

An arduino/Xbee board you might like is the seeedstudio stalker. Check around for a reseller closer to you.

It include a micro SD slot, a RTC and battery, and a XBee socket. I have one and like what it has to offer.

My recommendation to check out synapse isn't for my benefit. I really think you will like what they have to offer. The Radio modules have 20 General purpose IO Pins, 8 of which can be used for ADC. They have two serial ports. But, there is not an easy way to log to a SD card directly on the rf engine that I know of.

Good luck and please let us know how your project goes.

Simple home automation.

@zoomkat... Level UP!

Seeduino Stalker looks great, but it does not have USB connection. That is sad, as I do not have USB-serial adapter and I suppose it cost as much as I would save... I assume that I need to convert serial to USB.

I have read that Xbee is almost plug-and-play. How does Synapse compare to this? What about having several slave transmitters and one master. I know that with Xbee that should be possible but don't know about Synapse.