Sense one appliance - turn on another

Hi All
I know I could hack something together to do this but I have a feeling there will be something out there already....

I have the following setup:


Sat receiver------| S |
PS3------| P |
| L |--------- Downstairs TV
| I |
| T |----Wireless HDMI Sender ~~~~~~~~ Wireless HDMI Reciever-- Bedroom TV
| T |
| E |
| R |

This works pretty well in general. However it has a bit of annoying drawback. If I leave the Wireless HDMI Sender on but the TV upstairs off, then the splitter still thinks that there is an active output device attached and attempts to distribute a signal to the TV. Unfortunately it the satellite box (SkyHD) strongly enforces HDCP and as the TV upstairs is unable to respond appropriately the picture is shut off. I can rectify this by simply turning off the wireless sender downstairs. Unfortunately I don't like this and it's not fair on the none geeks in my family to have to understand this nonsense.

Big breath. What I'm looking for is a device that can detect that the TV upstairs has been turned on and correspondingly turn on the wireless sender (and receiver is possible). This would save the ugly fudge and also be a bit better for the environment.

Anyone got any ideas?? :smiley:

One way is to use one of those power strips that senses when something is plugged into it and turns on the other outlets. Of course, this doesn't involve an Arduino which takes all the challenge out of it. You might be happy taking one of those strips apart and incorporating the parts in an Arduino project. :smiley:

Thanks for replying :slight_smile:

I'd looked at those powerstrips - the trouble is the sender box is downstairs and the TV is downstairs. Those powerstrips work by sensing when the primary appliance (usually the PC) is turned on or off and switching the remaining sockets to suit. I've been taking a look at the HomeEasy stuff in the playground. I guess I could do it using:

1x HomeEasy socket
1x arduno
1x current sensor
1x 433 AM tx

I'd have the arduino monitor the power consumption of the TV upstairs. When it goes up indicating that the TV is has been turned on it would send the relevant HomeEasy command wirelessly to the HomeEasy socket gadget that would switch on the sender. Then vice versa when the TV upstairs is turned off. Would be nice if the HomeEasy people made a sensor socket that did this......

No self-respecting hobbyist would think twice about snaking an extension cord down the stairs. :smiley:

This hobbyist spent £150 (HDMI sender/receiver) to avoid running cables for this mess! but I appreciate the suggestion.

What about using arduino with IR receiver library to sense TV remote power button? Just tell your family they have to use the remote to turn on the TV. Or maybe if the TV has a power LED that turns on/off when the TV is on, attach LDR to detect it?!

Why not use some method of current sensing to detect if the tv is on/off. This could be a hall effect sensor, a modified kill-a-watt, etc. Then, send a signal to devices at the sender and reciever that turn them on/off correspondingly. I would imagine the sender and reciever could be turned on or off with an IR signal, no?

I'm afraid not. It seems to be an oversight on the part of the manufacturer that it doesn't have the capability to handle these circumstances. It would simply be a firmware change as it already relays sensed IR remote signals from the receiver back to the transmitter.....

What about monitoring the power on LED indicator with light-dependent resistor?

I think measuring its current consumption would be more reliable. The only issue is then how to turn on the sender and reciever. Do they turn on automatically if plugged in?

I have an arduino based solution (natch). I've roughed it out on a breadboard with an Arduino derivative I had handy and the concept works. Just waiting for some bits to be delivered to make the final product (Pro Mini based) :slight_smile: I'll share once I've cobbled it together. Thanks folks