Side Project: IR Control of an RF Device

I bought a TV cabinet for our living room that conceals the TV when not in use and has a mechanical lift operated by remote control that can raise it when you want to watch TV. Unfortunately, I didn't realize when ordering this cabinet that the remote control is RF, not IR and so can't be added to my universal remote to control it. There is no universal remote that can operate RF equipment or even any kind of IR to RF converter available that I could find, so an alternate solution was needed.

This isn't really related to the greater home automation project in any way, but it turned out to be a fun electronics project and I think people may find it useful.

 

Step 1: Buy extra TV Lift remote from the company that sells it. It was remarkably cheap. $15, and they even paid for the shipping.

Step 2: Buy electronics kit that can use IR to close a relay. (Velleman MK161) I originally thought this kit could use any IR code, but it can't. You need to also buy the 2-button remote control (Velleman MK162). These kits are just parts and need to be soldered together, but it's through-hole soldering and not too tough. I've seen some vendors who will also assemble the kit for you for a nominal fee.

Step 3: Assemble this stuff, and then take apart the remote and wire the relays to the button contacts on the remote. Basically, when the relay closes, I'm effectively 'pushing' the button on the remote (make sure MK161 is set to close relays only momentarily rather than toggle them off and on).

Unbelieveably, this thing actually worked. All I had to do now was make it nice. I bought a project box, and some little nylon stand offs from Fry's, then ordered the required power supply from DigiKey (and instead of just using the bare wires, I decided to also get a couple of jacks so I could just plug it in). I also picked up some IR window plastic so I could make the box look nice.

Step 4: Set to putting all of this stuff together. (Note, I was able to ditch the battery for the remote, since it was the same voltage as the power supply and required by the MK161. I just wired them up in parallel.

Step 5: Drill a hole in the box for the power supply jack and cut another hole in the front for the IR window (Dremel is handy here). Then you just use the standoffs to stack the boards a bit (I'm a bit of a hack, so I just glued them down).

Step 6: Add the MK162 remote to my Harmony. I made a new device, called it an 'Appliance' and set the two buttons as discrete on and off signals. Then just tell the Harmony software that you want the 'Appliance' on in every activity, and when you start up it will send the 'on' (up) signal, and lift the TV.

All Assembled, it's just a black box with a power supply jack in the back. Plug it in and basically make sure it has IR line of sight to your remote. Done.

 

I originally documented the above on AVS Forum two years ago when I first built it. Given that it was kind of hacked together by myself, I think longevity and reliability were legitimate concerns. Well, over the last two years it basically performed flawlessly, operating the lift up and down on request. However, the lift itself has recently failed. After removing the lift from the cabinet and disassembling it, I found a stripped plastic gear (with no part number or even brand name on the lift - cheap foreign crap). Even though I was able to order a spare remote from the cabinet manufacturer 2 years ago, I can't seem to find any trace of them anymore. Likely out of business. With repair being pretty much not an option, I opted to replace the lift with a higher quality piece. This lift was orderable with your choice of control system, so I ordered the IR control and my little box is going to be retired. I couldn't be more pleased with how well it worked though, and would employ this solution to solve a similar problem in the future.

Comments: 4 (Discussion closed)
  • #1

    Bill (Thursday, 31 March 2016 09:55)

    I know this post is pretty old, and you may never see it. I was wondering if you could expand on the details of Step 4 a bit. I have an RF remote for an Elite Screens electric remote that has 3 buttons so I have purchased a 4 channel IR receiver and remote. I also have an extra Elite Screens remote. I can't tell exactly from your picture how you connected/soldered the wires from the receiver to the VM remote then to the original manufacturer remote. It may not be easy to write out, but if you could help me out, that would be great. I'm using an IR blaster from a URC remote to turn into RF. Thanks.

    Bill

  • #2

    Nerdhome (Sunday, 03 April 2016 20:28)

    Bill, If you have the right kind of IR receiver kit it should be obvious on that end. It should be an IR to dry-contact relay kit and there are just terminals on the board for each of the relays that you can attach the wires to.

    On the remote side it was trickier. I had a relatively simple remote, and when I took it apart there were you could see the contacts that the remote button effectively closed when the button was pressed. That is where I soldered the wires to - so that instead of closing the circuit by the remote button connecting the contacts, the circuit was closed by the IR/Relay kit.

    Hope that helps. If you have any more questions, you can email me directly through the contact page on the site.

  • #3

    Scott (Wednesday, 13 April 2016 00:36)

    Hi, hoping you can help some more on Step 4 with regards to the voltage to the remote. The MK161 Velleman has a 12 V DC voltage input did your remote also have this? it seems to be a high voltage for a remote if running in parallel. I would think the original remote you used had a AAA battery. Or did you use a lower power source to supply power to the MK161 by Velleman? Perhaps I am missing something here. Also, does any adjustments need to be made so that the output voltage to the buttons are not to high? Thank you in advance.

  • #4

    David haag (Saturday, 30 April 2016 22:29)

    If you could please help me with this if you can...I use the harmony hub and the app on a tablet as my control. I purchased and built the velleman mk161 and I'm useing it for a projector screen which is rf.my screen has a remote and also a control box ( up,down and stop) built into the power line. I'm guna wire the velleman mk161 into the power box. The problem I'm having is how do I setup the velleman mk161 on my tablet remote? I've Hunted high and low to find out how to do it but have found nothing...please if you can help I would be truely greatfull!!! Thanks