DAC in arduino DUE

hi, i wanna know if the DAC in arduino DUE can generate a voltage!! thanks

That's exactly what it is does.

http://arduino.cc/en/Reference/AnalogWrite

The Arduino Due supports analogWrite() on pins 2 through 13, plus pins DAC0 and DAC1. Unlike the PWM pins, DAC0 and DAC1 are Digital to Analog converters, and act as true analog outputs.

, thnks :slight_smile: , and the maximum value is???

Less than 3.3v

Keep in mind it can't source much if any current, so don't expect to power something with.

If you want good answers, explain what you are trying to do.

i want to command a wheel chair. i need to give the main card 2 values, the max one is 3.9v , what can i do now!

According to this post - Arduino Forum - the Due's DAC can deliver a voltage between about 0.55 V to about 2.75 V. The low limit is 1/6 of 3.3 V, and the high limit is 5/6 of 3.3 V.

shtranka:
i want to command a wheel chair. i need to give the main card 2 values, the max one is 3.9v , what can i do now!

You can start here - http://www.eng.yale.edu/ee-labs/morse/compo/sloa058.pdf - and develop an op-amp circuit to add gain and offset to your signal. Note that you'll need a rail-to-rail op-amp if you intend to power it from a 5 V supply. If you use a general-purpose op-amp, without the rail-to-rail feature, you'll need a positive voltage of something more than 5 V; if you need to get close to ground, you'll also need a negative supply.

and can i use both of channels in the same time ( different values)

Yes, but be very careful what you connect it to, a lot of us have accidentally burned ours.

The opamp suggestion from tmd3 is a good suggestion, without this or a similar buffer between the DAC and your load, your DAC might not last very long - mine didn't

Duane B
rcarduino.blogspot.com

DuaneB:
Yes, but be very careful what you connect it to, a lot of us have accidentally burned ours.

The opamp suggestion from tmd3 is a good suggestion, without this or a similar buffer between the DAC and your load, your DAC might not last very long - mine didn't

Duane B
rcarduino.blogspot.com

The easiest way to protect a pin is to put a resistor on it so it cannot source too much current. Whatever the maximum safe current is for that pin, place a resistor in series with it that limits the current to something less than that.

the AOP is a good idea but the values that i will generate are not constant( obstacle avoidance) it means it can change instantly and any direction has its values (exp to turn right i must give 3.9v and 2.5v)

Your not going to get from 2.7 volts to 3.9 volts with just a resistor for help.

Why do you think an op amp is not going to change value when you ask it to ?

Duane B

rcarduino.blogspot.com

so 2 op amp are enough to deliver 16 different values automaticlly!!!

would you plz give an example of such circuit! because i still don,t have the arduino and i wanna make sure before i buy it. thanks

an opamp can "deliver" an almost infinite number of "values", all it does is amplify and/or shift what you give it.

If you give it 16 different levels you will get 16 different levels out of it that may or may not be the same as the inputs depending on how you construct the circuit.

What exactly are these values you need, 16 equally spaced from 2v7 to 3v9?


Rob

i have 8 directions and each one has 2 axis, and i have sensors, so what i need is to run the wheel chair automaticly to avoid obstacles. so it depends on the position of the wheel chair and his next move without any intervention of the user.

Figuring out what the OP wants to know is a lot work.

shtranka:
would you plz give an example of such circuit! because i still don,t have the arduino and i wanna make sure before i buy it. thanks

I think he's asking for a gain-and-offset circuit using an op amp, but I can't be sure. Here's another place to start:

The document says, "The design requires no theory and very little math." If it can hold to that promise, it ought to be just right for this application.

i wanna an op amp that divide the input value by 2 i think it can solve the problem.but i need a very precis one, do you know any one.

Op amps don't have to be "precise" - that is the whole point. What needs to be precise are the resistor ratios used to set the gain.

yes i see, so don.t you any circuit can do that function??

Check out any op-amp cookbook.