AD5206

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi Everyone,

I want to use the Arduino to control a circuit that currently has three pots: 25k, 50k, and 100k. I'm wondering if I could just use one 100k AD5206 and attenuate the two other channels, for instance doing something like HIGH*.5 to set the 50k one to max. Any idea?

Thanks,
Zach

2

Need to know more about the circuit to tell if that would work. Are they used as pots or just variable resistors?

3

Um...I thought those were exactly the same. The circuit is here: tonepad -- file information.

Thanks,
Zach

4

I thought those were exactly the same

No, it depends how you connect them.
A potentiometer acts as a potential divider with two variable resistors (the length of track either side of the wiper), whereas a variable resistor is ...just that.

5

I think these are used as potentiometers, since all the terminals are used.

6

So, what's the answer?

7

So, where's the circuit?

8

I linked to it above: tonepad -- file information. The schematic is in the pdf.

9

I wasn't planning on changing the pot sizes, just wondering if I could simulate a smaller pot by sending less voltage to a larger digipot (i.e. HIGH*.5 to create 50kohms on a 100k digipot- I realize I'll have to use SPI though). I'm not sure if they work that way and would appreciate if someone could explain.

10

are you using it as somethign like a dimmer switch, or are you analogRead-ing it on an arduino?

if you are talking abouf analogReading, the ohms of the pot doesn't matter... if you are talking about a power limiting knob (dimmer switch, volume knob, ect) then I do not know

11

Richard, I definitely don't understand how they work. I've actually never used a digipot before- I was just trying to figure out which parts to order. Based on the circuit, I guess you're telling me to get one 50k digipot and one 20-25k one?

12

I believe the AD5206 has 6 terminals and I was hoping I could just use one digipot, so as to simplify the wiring.

13

Thanks, Richard. I think I'll give that a try. Limiting the range is what I was trying to communicate and I understand now why that would only work with a variable resistor as opposed to a potentiometer.