analog voltage

Other Hardware General Electronics
1

hi,
I have an arduino uno, and I want to generate a variable analog voltage ,
if any one have an idea?

2

low-pass filtered PWM?

External DAC chip?

R-2R ladder from several digital pins?

What resolution do you want? What bandwidth?

3

how can i make the external DAC chip (i want a voltage between 2-5v)?

4

how can i make the external DAC chip

You buy the chip, something like a MCP4921 and solder it into a circuit.

5

I prefer the MCP4821 (actually the MCP4822 is even nicer - 2 channels) as it has an internal voltage ref. By default you can create voltages between 0 and 2047mV in 0.5mV steps, or 0 and 4095mV in 1mV steps.

The MCP4921/MCP4922 requires an external voltage reference. Yes, you can connect it's reference input direct to your 5V, but then the output is dependent on the stability and accuracy of your 5V rail.

6

How many amps of output are you looking for? Most D/A chips are less than 20ma.

7

ok,
the MCP? how can i connect it with the arduino

8

Through SPI. I wrote a little library ages ago for it: http://hacking.majenko.co.uk/MCPDAC

9

sorry, but i can't get the file

10

Here it is then.

MCPDAC.zip (2.36 KB)

11

thank's,
but because i work the LABVIEW softward, i don't know if the MCP is suitable
do you know about labview?

12

I have no idea. What is this Labview of which you speak?

13

in this program, i want to générate the voltage ramp through the arduino.

Untitled 1.vi (14.8 KB)

14

What on earth is a .vi file?!

15

i realize that you don't have any idea from labview
thank's for your help.

16

do you know about labview?

Yes

arhemza:
thank's,
but because i work the LABVIEW softward, i don't know if the MCP is suitable

It is irrelevant, it is just as good as any other Arduino peripheral chip.