UHF Remote

[flyswatta]

I was wondering about that. It looks like pushing the button merely completes the circuit - ie. routing voltage to one side of the circuit. I was wondering if it were possible to send the "correct" voltage over a parallel port line (perhaps having a wire soldered per button). Determining the correct voltage is where i'd be lost. Of course, there wouldn't be enough wires for EVERY button, but certainly enough to be able to do numbers, which is about all GBPVR is going to send anyway.

I'm just speculating, I could be way off base here.

[pBS]

yea, i was thinking you could set second remote to ir and then learn those ir commands and try sending those to see if they change the second tuner's channels...assuming there are different ir signals for each remote, then it should work...one set of ir commands for video1, and one for video2...
[almost like separate boxes]

i'm goin over to my sis's tomorrow and they have one of these, and i can look thru the manuals for any clues..

[pBS]

looks like it can never be controlled with the ir, so only option is to get ir control of a single tuner and feed that to gbpvr...

the box i was looking at is slightly different...[home gateway]

[flyswatta]

You can only use UHF for the other tuner, although the remote is identical for the IR side. You have to "flip a key" inside the remote to switch it from IR to UHF. I've spent several months trying to figure out how to control TV2 via the ir and you just can't do it. :mad:

[Ted the Penguin]

I was wondering about that. It looks like pushing the button merely completes the circuit - ie. routing voltage to one side of the circuit. I was wondering if it were possible to send the "correct" voltage over a parallel port line (perhaps having a wire soldered per button). Determining the correct voltage is where i'd be lost. Of course, there wouldn't be enough wires for EVERY button, but certainly enough to be able to do numbers, which is about all GBPVR is going to send anyway.

I'm just speculating, I could be way off base here.

hehe, electrical engineer to the rescue!!! :p

so how most remotes work is they have a pressure sensitive switch, that is what completes the circuit. you should measure the voltage across and current through this with a multimeter, both while on and off. as I remember (I took electronics a few years ago) you should be able to replace that switch with a transistor, and as long as the remote has the same ground as whatever you are triggering it with (you should just be able to connect one of the ground pins to the remote ground) you can put the transistor into saturation with a serial input, and allow current to flow to the rest of the circuit triggering the button.

now... as for number of input lines... you really only need 4, as you can use some binary logic circuitry to break them out into 16 separate signals... but having 10 would be easier.

if you need more help with this stuff I can do a bit more "remembering" aka looking up stuff on google to remind me how circuits work. just let me know

good luck

[pastro]

Chances are the remote keypad is a multiplexed keypad with column outputs and row inputs. That means you can't just pull a pin low or drive it high to get the button to work. You have to essentially drive a switch that connects the column to the row. That can be done with a Mosfet. The hardest part is to figure out what the row and column matrix looks like so you can add the switches in the right spot. This may be tough to determine without a oscilloscope since the column drivers will be driven for a short period of time (and the row read) and then it moves to the next column. Finding a schematic for the remote might help, but it could just be a custom little processor and not a dedicated keyboard encoder.
If you need more info I'll find a simple schematic that will show what I'm talking about.