Connected space heater

[syoutsey]

Hey all,

I'm looking at building a setup which will act as a remote on/off switch for a space heater. I plan on buying a heater with a switch that you can essentially unplug from the wall to turn it off and plug it in to turn it on.

I'd like to build, using an Arduino or Raspberry Pi, something that will poll an internet resource and turn the heater on/off. Using the Arduinos pin outs I'm hoping I could accomplish this. I can handle the software side of the device (I'm a software engineer by trade) but would love some help on what kind of hardware to get setup. A relay connected to the Arduino? Any input would be great.

Thanks!

 

[(*steve*)]

When you say "remote controlled" are you meaning "wirelessly avtivated" or are you talking about using a low level control signal along a cable (e.g. a 5V signal or an open/closed circuit that carries a few mA).

If you want a small signal through a wired interface, there's no need for an arduino. Just a signal cable, and a transistor to drive a relay (plus a few ancillary components)

If you're thinking wireless, then perhaps you could read this thread where an option that you could use was raised (but probably abandoned due to a better solution being found)

https://www.electronicspoint.com/serial-wireless-communication-t265255.html

 

[syoutsey]

When you say "remote controlled" are you meaning "wirelessly avtivated" or are you talking about using a low level control signal along a cable (e.g. a 5V signal or an open/closed circuit that carries a few mA).

If you want a small signal through a wired interface, there's no need for an arduino. Just a signal cable, and a transistor to drive a relay (plus a few ancillary components)

If you're thinking wireless, then perhaps you could read this thread where an option that you could use was raised (but probably abandoned due to a better solution being found)

https://www.electronicspoint.com/serial-wireless-communication-t265255.html

It'd be wireless as it's in a room where it's tough to run wires. So, the ideal setup would be the arduino polling a web resource every minute or so to see if a value has changed, and if so open/close the relay accordingly. Is there a relay you can recommend that would respond to the arduino or another place where I could dig up this info?

Thanks for the reply!

 

[(*steve*)]

I guess the first thing is the relay.

You need to know the voltage to be switched and the maximum current.

Find a relay with contact capable of that (and preferably quite a bit more -- current especially) with a 5V coil (since the arduino is probably running from 5V)

Then find a transistor or mosfet which will be used to power the relay from the arduino, a resistor (to limit base current for bjt, or to tie the gate to the source for mosfet) and a diode to catch the inductive spike generated when the relay is turned off.

If you google "arduino relay" you'll find as many examples as you need. Here is just the first one I clicked on.

In a practical sense, it will be easier to send a signal to the arduino than it will be for it to poll a web resource, but you should be able to find examples of the latter too (but it will require more interface stuff)

 

[syoutsey]

I guess the first thing is the relay.

You need to know the voltage to be switched and the maximum current.

Find a relay with contact capable of that (and preferably quite a bit more -- current especially) with a 5V coil (since the arduino is probably running from 5V)

Then find a transistor or mosfet which will be used to power the relay from the arduino, a resistor (to limit base current for bjt, or to tie the gate to the source for mosfet) and a diode to catch the inductive spike generated when the relay is turned off.

If you google "arduino relay" you'll find as many examples as you need. Here is just the first one I clicked on.

In a practical sense, it will be easier to send a signal to the arduino than it will be for it to poll a web resource, but you should be able to find examples of the latter too (but it will require more interface stuff)

Great, this is excellent info. Thanks for the help!

 

[Solidus]

Great, this is excellent info. Thanks for the help!

Just a small tidbit - you can find wireless modules for the Arduino that (for the most part) simplify the coding. You might Google Xbee modules or something of that nature. The Arduino framework has built-in libraries that simplify the coding aspect to a few initialization procedures and ideally, just serial communication.

The usual use of these is with another Arduino for transmit/receive, but I know of a few modules that use the Bluetooth standard. These have the advantage of being able to be talked to by any laptop, desktop or phone that has a configurable BT transceiver and a program to talk over the line with.

Hope this helps a bit.