pga2310 volume control with motorised pot

[ialpha]

Hello i'm new to the world of audio electronics so not really sure how to go about this. I have been playing with the idea of building a 5.1 pre amp based around 4 burr brown/ti pga2310. I like the idea of a remote controlled motorised pot but am unsure how to get one to control the pga2310's. Then using a pic I want a LCD screen to display the volume level db.

I have never used the pga2310 so am unsure what the audio quality is like from these devices, are there better options available ? Are there single devices that control 5.1 or 7.1 surround in one package

I'm guessing the quality of the pot is not so important as the real work is been done by the ic.

I also thought it would look cool if I could have a series of leds around the edge of the volume control that light up in sequence as the volume is turned up and down, how would I go about achieving this?

[janneman]

Originally Posted by ialpha

Hello i'm new to the world of audio electronics so not really sure how to go about this. I have been playing with the idea of building a 5.1 pre amp based around 4 burr brown/ti pga2310. I like the idea of a remote controlled motorised pot but am unsure how to get one to control the pga2310's. Then using a pic I want a LCD screen to display the volume level db.

I have never used the pga2310 so am unsure what the audio quality is like from these devices, are there better options available ? Are there single devices that control 5.1 or 7.1 surround in one package

I'm guessing the quality of the pot is not so important as the real work is been done by the ic.

I also thought it would look cool if I could have a series of leds around the edge of the volume control that light up in sequence as the volume is turned up and down, how would I go about achieving this?

Hi,

Looks like you need a microcontroller. That could do all you need:
Use the pot to make a variable DC voltage,
Read the DC with the ADC that controllers have on-board,
Convert the DC to a needed level,
Send the needed level out from the controller to the PGA's on the serial link,
Make the controller light the LEDs on the vol control perimeter as needed.

The thing is, if you'r in microcontrollers this really is a no-brainer, but if not, you'll need someone to do it for you or spend a few months learning it yourself.

BTW The CS3318 has 8 channels of level control. I use it in my DCX2496 mod.

jan didden

[mirlo]

If you do go with a microcontroller, you might want to try a rotary quadrature encoder and skip the motorized pot and a->d tedium. The encoder will produce up/down information for the microcontroller.

[ialpha]

Thanks for both your reply

Originally Posted by mirlo

If you do go with a microcontroller, you might want to try a rotary quadrature encoder and skip the motorized pot and a->d tedium. The encoder will produce up/down information for the microcontroller.

I was looking at using something like this but the only reason I thought of a motorised pot was they give you can get a idea of how loud the amp is set to before you turn it on. My wife tends to crank up the volume when im out. I come home put on some rock music and my sensitive ears get blasted, not to mention my poor speakers. With a pot you know when you turn the dial all way to left its going to be low volume and hard right will break all your windows and most likely your speakers. With a dial that turns for ever you just don't know what the volume was when it was turned off. Just a thought

[theAnonymous1]

Originally Posted by ialpha

With a dial that turns for ever you just don't know what the volume was when it was turned off.

You could also program the controller for a preset startup volume.

[ialpha]

Ok looks like im going to have to invest some time in learning all about microcontroller's can anyone recommend a good book?

[wakibaki]

If you just google 'pic micro tutorial' then you will find more than a page of different tutorials for the Microchip PIC, one of the most popular microcontrollers. Many of these are flash-based, i.e. they can be reprogrammed repeatedly. An economical programmer is the Pickit 2. If you buy the Debug Express version it comes with a demo board and PIC 16F887, the demo board will allow programming of 44-pin devices. There is a slightly cheaper version demo board which does 20-pin devices, and you can save some money by buying a clone Pickit 2 off ebay, and building your own adapter (demo) board, but none of these are very expensive, and if you buy a genuine Microchip example it comes with a number of working example programs, tutorials, and programming software on a CD. Again, you can download the software free from the Microchip site. The 16F887 has an A/D, internal clock and numerous other built-in features.

I use the Pickit 2, I have programmed numerous applications, and I recommend it to anyone interested in general electronics as it simplifies the addition of control and timing functions to many projects.

There are alternate and almost certainly equally capable flash microcontrollers such as the Atmel AVR.

w

The Pickit is an in system programmer, so you can't program devices without either an adapter board that you can plug the chip into temporarily or a 6-pin header on the target project.

[janneman]

If you go with a PIC, check out FlowCode from Matrixmultimedia. It's a very user-friendly graphical progarmming environment that hides all the tedious comamnd codes and syntax and lets you do just what you want - set up a program.
It'll help you make the leap from zero to programming very quickly.
It has lots of examples and ready-to-rum modules, and supports both PICs and AVR and ARM controllers, as well as standard peripherals like switches, displays, encoders, serial link to PGAs, stuff like that.

jan didden

[ialpha]

Thanks everyone for all your reply's have started working through the wealth of information on the net. Downloaded and am playing with a copy of FlowCode. will post back if I need more help

[Nisbeth]

Russ White from twistedpear did this in their "Kookaburra"-preamp. I believe the code is available in an old diyaudio thread about this amp, otherwise I think Russ might be willing to release it to you since they are no longer selling the amp.

/U.