[Doh]

Hey everyone,
Just thought I'd share a link to an easy to use remote control IC. It's already programmed and all you need to add is a IR reciever chip, which is also available through the same site. It operates through a standard Sony remote.

http://www.rentron.com/remote_control/IR-D14.htm

Cheers,
Doh

 

[ppl]

Doh> Thanks for the tip. That is one of the more symple Remote Receiver Circuits i have seen and Heck you can get the entire preprogramed working IR system including a RC Remote with Batteries from them How simple can it be. Good find

 

[blip]

That is pretty cool... Has anyone used it? Does it really live up to the hype?

 

[Doh]

I got one coming my way. Not sure exactly how to drive a motorized pot with it, but I think that my Gilmore Preamp will have its relays switched with this thing lashed up to a couple of TIP29 transistors. Sorta stealing the idea from a relay-based stepped attenuatory schematic I came across at DIYAudio. I just hope it'll work.

-Doh

BTW, this Gilmore preamp project is getting to be quite a big one. I've got the antness amplifier board and power supply, a separate 12V/5V power supply that I picked up surplus to power the relays, and boards for relay switching, and now a remote control unit. If I have space in the box after this, I might go nuts and turn it into an integrated amplifier!

 

[Possum]

To drive your motorized pot, you can use an H-bridge IC (we're using L6203 for our robot drive motors, but it's probably overkill for a volume pot motor). You use the pin outputs associated with the volume up/down on the receiver chip as the logical input to the H-bridge to enable it and choose the motor's operating direction.

 

[Doh]

Thanks Possum!

 

[Possum]

Doh,

Did you purchase and try out the IR unit yet? I'm gathering together my parts lists and am trying to buy as much as I can think of for now for three different subsystems (similar to your preamp idea): amp and power supply, microcontroller-based relay switching, and IR remote control with motorized volume control.

 

[Doh]

I have the IR unit in hand, but am trying to get some help setting the darn thing up. Details can be found at the following thread:

http://www4.head-fi.org/forums/showt...threadid=19207

Unfortunately, I am totally clueless when it comes to the design of electronics and need help figuring out the resistor values required for the input switching. The H-bridge will have to wait until I have this part of the project done. Current plan is:

1) Kevin Gilmore headphone amp (waiting on chassis parts now, as well as some boards for the amplifier portion)
2) Upgrade to Kevin Gilmore preamp with input switching
3) Upgrade to remote control volume control

Any help would be greatly appreciated.

-Doh

 

[Possum]

Here's my plan:

1) All relays will be normally open except the selected signal relay, which will remain normally closed so the signal doesn't have to pass through the coils of the relay

2) Since I don't like dealing with too many parts mounted to the chassis, I'm going to use a simple 6-position rotary switch (I ordered the $20 GrayHill one from Welborne Labs

) as an input selector - but all this switch does is connect a "high" signal (5 VDC) to any of 6 input pins on a microcontroller (I have an Atmel AT90S2313 ordered). On power-up/reset, all output pins that trigger the relays are first high (to disconnect all input signals). The microcontroller will check to see which pin the rotary switch is signaling high, and will select that source as an input (outputting a corresponding pin low to un-trigger the relay for that source). However, to implement the remote control, the output of the IR's microcontroller from Reynolds Electronics will set 1 pin of a 2nd set of 6 pins high. The microcontroller at this point will use a "latest-input policy" to select the output. So if the rotary switch is set to one source, then the IR IC outputs another source, the microcontroller will switch the relays for the source picked by the IR chip. But if you go and move the rotary switch, the microcontroller will change the relays for that setting.

The microcontroller output to activate the relay circuit will have to be experimented with, since the microcontroller pins can only output like 20 mA, and the relays that I'm looking at are 28-40 mA or so.

Edit: I just realized that the AT90S2313 doesn't have 18 I/O pins... I'll probably test the algorithm with that chip then move to the 40-pin AT90S8515, since I have a few of those already.


3) Volume control using the IR chip, the 16-pin DIP L293D chip from STM electronics (ordered from Mouser), the 10k Alps motorized pot from PercyAudio.com, and the corresponding PCB available from Percy for the motorized pot. I'll have to experiment with the circuit involved with the h-bridge to see what the current limit should be for small motor movements (hence small volume adjustments).