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Iriver HXX0: remote control

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bluebrother:

--- Quote from: Tirithen on April 21, 2008, 12:02:21 PM ---The thing I wonder is how to make the simplest experiment by connecting a resistor with a value of 470 ohm to RMC connector to invoke the + button . Should I simply connect the resistor from the RMC to GND or do I need to connect it in some other way?
--- End quote ---
if you just want to fake that button just pull RMC to GND using 470Ohms. To fake the various remotes that are around you also need to use a resistor -- but I don't remember how that was connected. The remote will work without that, it's just used to distinguish the types around. If you look at the GPIO debug screen you can see the ADC value that correspondends to RMC.

Theoretically, you need to pull RMC to any voltage between 3.3V and GND and it will directly correspond to the ACD value. The (a bit harder) part (where I stopped working on this for now) is to feed enough current to the ACD -- my R2R network wasn't good enough. It's not an issue if you simply use a resistor, but it gets more tricky if you want to interface it with a microcontroller ...

Tirithen:
Thanks for the debug screen tip,I'll compare this to the schematic on:
http://www.rockbox.org/twiki/bin/view/Main/IriverH3XXHardwareComponents#H300_Responses_from_iRiver_H300

And I guess it should work. I've managed to get >> button working so far.

I'm still new to pic's but there must be some way of making them to control resistance, pic + a transistor in some way... haha I have to get better at this.

bluebrother:

--- Quote from: Tirithen on April 21, 2008, 12:47:17 PM ---I'm still new to pic's but there must be some way of making them to control resistance, pic + a transistor in some way...
--- End quote ---
You need an DAC. If you can produce a clean voltage you most likely could feed it directly to the TLV0834, given that its in the correct range. You could easily feed the µC using the voltage on the remote connector. µCs usually don't have an DAC build in but rather ADCs. Also, for the TLV0834 (which does the opposite, ACD) to work correctly the signal needs to be stable enough in its value. A simple DAC would be a R2R network (which I already tried), but the TLV also needs some current -- your DAC needs to provide enough, my R2R network didn't.

Tirithen:


I have made a remote with resistors for 10 buttons + play + hold (see attachment). It's a bit messy soldering but it reports the values that I got on my testboard on ADC_REMOTE:

00 Stop
17 -
31 A-B
4A +
65 "+10"
7D Rec
94 "-10"
B3 >>
CD NAVI
E6 <<

The problem is that the values no longer triggers the same instructions as before, the buttons makes the wrong things. I guess this has something to do with remotetype variable, now I have value 2 but it might have been some other value when I tested on my testboard. Are there some way to get the values above to correspond to the buttons above, it worked so good yesterday... :-/

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