Outroot and things

Electronics, programming, computers, and geek stuff by Kevin Darlington

Repur­posed tv-b-gone

At church, we have a pro­jec­tor that is close to the ceil­ing and far away from the audio/video booth. The remote con­trol that came with the pro­jec­tor does not have a very far range. I have to get out of the booth and walk close to the back row and keep mov­ing the remote until I get the pro­jec­tor to turn off or on. It wasn’t only annoy­ing for me, but I’m sure it was dis­tract­ing for the church members.

The solu­tion to this prob­lem is an easy one: build a more pow­er­ful remote. The first order of busi­ness was whether I would build one from scratch or if I was going to mod­ify some­thing else on the mar­ket. Since the IR LEDs that I wanted were out of stock at mouser (and I dis­like digikey’s ship­ping price), I decided to just buy a tv-b-gone kit from adafruit.

This kit was sim­ple to put together and I was able to turn off all of my TVs in no time. I took the device to church in hopes that the IR code for the pro­jec­tor was already pro­grammed in, but no such luck. In order to get the code for the benq pro­jec­tor, I put together an arduino with an IR receiver and used the IRre­mote library by Ken Shirriff. I love the library that he cre­ated. It not only gets you the raw data for the pro­to­col, but it also tries to deter­mine what pro­to­col it is. The IRre­mote library told me that the benq pro­jec­tor that I had used the NEC pro­to­col, code B14E00FF.

Now I needed to get this code onto the tv-b-gone. I read through the design doc­u­ment for the tv-b-gone, and was eas­ily able to trans­late the raw IR code into the com­pressed tv-b-gone format.

Tv-b-gone at church

Ver­dict? It worked per­fectly. I didn’t have to move from my seat to turn off/on the pro­jec­tor (in the pic­ture, I’m hang­ing over the booth to get a good picture).

You may have noticed but I put the tv-b-gone inside a Maxim case I got when I ordered some samples.

Maxim case

All I did extra was drill 4 holes and put a small push­but­ton in the front of it, then sol­der wires to it and the but­ton on the PCB. The bat­tery case is stuck on the bot­tom with dou­ble sided sticky tape.

Push­but­ton on case

Sol­dered to push­but­ton on PCB

Code

I changed the code up a bit from the orig­i­nal firmware. I removed some unnec­es­sary delays and LED blinks, and I obvi­ously removed the rest of the TV codes. I used AVRStu­dio to write the firmware and USBtiny­ISP to pro­gram it.

Inside the zip, I include an analy­sis folder which con­tains the IR code for my pro­jec­tor. “analysis/ir.txt” is the more inter­est­ing file.

church_benq.zip

This entry was posted on Tuesday, February 23rd, 2010 at 1:21 am and is filed under AVR, Electronics, Microcontrollers. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.