Feasibility of my IR blaster project idea

[JayKay]

Hi everyone,

I recently stumbled upon the mysensors.org site and now i am hooked and I want to create my own network. For my first project I have the following idea, and it would be nice, if you guys could give me input on whether it is feasible and what the necessary resources would be for me to find information.

I want to build a battery powered wireless IR blaster node.

The reason is this: In my living room I have a "smart" TV and an old AVR and an LED strip all on one wall opposite of my couch.

The smart TV can be controlled via wifi, but only once it is turned on. If it is in standby I can only wake it via the IR remote that comes with it (so stupid).
The old AVR can only be controlled via IR and the LED strip can also be controlled via IR.

Now since the side of the room with the couch doesn't have any shelves or anything I really don't want to have a wire running up the blank wall to some IR blaster that then controls the appliances on the opposite side of the room, so it would be nice to have the IR blaster be battery powered and in a nice unobtrusive, compact, white casing. This would even allow me to stick it to the ceiling.

Now there are tutorials on how to build IR blasters with Arduino, and there are tutorials on how to build a MySensors node and gateway, and there are tutorials on how to use OpenHAB to control this network AND there are tutorials on how to build battery powered nodes, BUT I don't know if it even makes sense to try and build a battery powered node that is not just a sensor that infrequently wakes up, takes a measurement and sends it back to the gateway.

I have a feeling that constantly listening to wireless signals so that the node can react and blast an IR code will drain a battery fast.

Can any of you guys tell me if this is even a reasonable possibility that will give me at least 3 months of battery power on 1 or 2 AA batteries? And if so: What would be the relevant tutorials for me?

Also another question: Since I want to have redundancy in case my OpenHAB controller fails, it would be nice to have the
MySensors gateway attached to the LAN via ethernet, so that another controller can take over without needing its own gateway. I have read conflicting posts on the forums on whether an ethernet gateway will work with OpenHAB. So does it?

Thanks very much to anyone who takes the time to read or answer my post!
Cheers
Jay

[BartE]

Hi @JayKay,

You might want to have a look at this post: http://forum.mysensors.org/topic/1402/ir-blaster-progress
and this post might help you as well http://forum.mysensors.org/topic/2413/ir-record-and-playback-module

Cheerz
BartE

[JayKay]

@BartE

The first link is exactly what I would have started to do if I wanted to build just the IR blaster and have it run via a 5V power supply. But since I am wondering if it can be done battery powered it would be nice to get some info on that.

The second link is going to be helpful in figuring out my IR codes, that's great, thanks!

[BartE]

@JayKay

You can run the blaceys IR blaster on batteries, by using a DC set-up module

But keep in mind that a battery powered node which is continuously listening to the MySensor network means the radio and processor never can go to sleeping mode causing a shorter battery lifetime. So for you idea an power supply is preferred.

[JayKay]

@BartE
Ah interesting, there is a ready-made thing that supplies the Arduino from batteries.

But basically what you said is exactly what my question boils down to: Is it feasible to run something like this on batteries?
What would (just roughly) be my estimated lifetime?

[BartE]

@JayKay that's hard to tell one can measure the power consumption. A standard AA battery will deliver ~2500mAh

Here is some more background information about running MySensors on batteries: http://www.mysensors.org/build/battery

[JayKay]

@BartE

That looks like very important basics to get any battery-powered project off the ground, but even in this tutorial they basically just mention sleeping and infrequently polled sensors. My gut feeling tells me this is not going to work.
Too bad

[tbowmo]

@JayKay

an IR blaster would probably have to be turned on, and with radio link active, all the time so it can be ready to receive commands from the controller.

NRF24 uses ~14mA in receive mode (with radio turned on, and ready to receive commands). if you are using standard 2200mAh batteries, the theoretical battery life would be 2200mAh / 14mA = 157 hours, or 6.5 days.

So you should have a large stock of batteries

(Numbers above is purely from the top of my head, without checking datasheets etc.)

[JayKay]

@tbowmo
That is exactly the kind of rough estimate I was looking for and it does confirm my doubts. Thank you very much.

[mfalkvidd]

@riataman has a solution here that might be useful.