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31  Using Arduino / Sensors / Re: how fast is the digitalread function? on: July 27, 2012, 12:54:47 am
You're going to need a modified project or a different processor.

The first issue is getting an ADC that will do 500ksps, they're around but not internal to any small processors such as used on the Arduino. But then you have to read the data from the external ADC and do power calcs as well, all in 2uS.

Short answer, not on any current Arduino. The Due has an ADC that will do 1msps, there's just a chance you can do it with that if your code is very well written.

How long do you need to sample for? If it's just a short period you may be able to save the data and post process it.

______
Rob

I was also thinking about a chipkit controller. Maybe these are fast enough for what I need.

 I want to calculate how much power my amps are using so I can switch them off automaticly when there is no music playing for 20 minutes or so. I don`t think it should be necessary to measure all the time. Maybe even less measurements per second will also do. 

I want to measure it in the ac line (230 volt @ 50Hz). So one sinewave is 1/50 = 20 ms. I had in mind to make 10 easurements per sinewave so I can calculate  really accurate the used current. When the used current is stable for some time, it must mean that there is no music being amplified.

I know that one can easily buy power killers and plug the between the apparatus and the wall socket, but I want to build this myself inside the amps.
32  Using Arduino / Sensors / Re: how fast is the digitalread function? on: July 27, 2012, 12:28:26 am
Did you mean how fast is the analogRead?

Oh ....' I do mean analogRead.
33  Using Arduino / Sensors / how fast is the digitalread function? on: July 26, 2012, 02:26:22 pm
how fast is the digitalread function? I am trying to find out if a arduino is suitable for my project.

I want to measure the voltage over a precicion resistor every 2 microseconds to calculate the used current as accurate as possible.
34  Using Arduino / General Electronics / Re: Connecting both USB and 2.1mm center-positive plug on: June 26, 2012, 12:26:12 pm
Thanks!  That is what I needed to know. It would be a pitty if this couldn`t be done.
35  Using Arduino / General Electronics / Re: Connecting both USB and 2.1mm center-positive plug on: June 26, 2012, 06:54:36 am
I do indeed use the arduino Uno.

So this means that I can connect both at the same time without frying it?
36  Using Arduino / General Electronics / Connecting both USB and 2.1mm center-positive plug on: June 25, 2012, 04:10:03 pm
Hi,

Would it harm the arduino when I connect both USB and the 2.1mm center-positive plug at the same time? I can imagine that some shorts will occur when connecting it to two power sources.
For my project it will be powered via the 2.1mm center-positive plug, but for easy access to the code I want to have a USB connector build into the chassis and a cable from there to the arduino. This way I do not have to open the chassis to update the code.

37  Using Arduino / Programming Questions / Re: Using breakpoints for debugging on: April 23, 2012, 03:31:30 pm

Maybe on one of the simulators - http://arduino.cc/forum/index.php/topic,98306.0.html -

I will dig into it. Thanks.
38  Using Arduino / Programming Questions / Using breakpoints for debugging on: April 23, 2012, 02:04:44 pm
Hi,

I'm new to arduino, but not to the programming languages C# and VB.

Is is possible to use breakpoints in the code for debugging, just like when using visual studio or similar?

I only found this:  put "debugging prints" inside your code.
Is there no other method for using breakpoints?
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