Hi guys, I know this topic must have been discussed already, but I'm not here because I'm to lazy to click on "search".
I haven't started working in a code yet, mostly because I don't really know how to do start it.
I'd like some directions, which would show me the way to start looking for answers that I need.
I've been working on a project, in which I generate sine waves to be used in a communication between piezos. I used a DDS AD9850 board and with some capacitors, op amps and resistors I got a good output (sine waves with 4V, 30-50KHz).
As I've learned, my output is analog, and now I have to make it digital in order to be read by the arduino.
My main objective is to be able to read the frequency of the wave.
All the analog to digital conversion I've seen so far aim to get the voltage and not the frequency.
Can you guys give me any direction?
I really appreciate your help.
Thanks.
use a digital input.
Function "pulseIn()" can measure HIGH and LOW times. Add them to get the period of your frequency
As I've learned, my output is analog, and now I have to make it digital in order to be read by the arduino.
My main objective is to be able to read the frequency of the wave.
All the analog to digital conversion I've seen so far aim to get the voltage and not the frequency.
Can you guys give me any direction?
To be able to read (measure) the frequency in an arduino you need to look for a frequency counter sketch. Trying to read the frequency of a signal via analog input pins is a very intensive software effort and probably not something you should consider. There should be many references to frequency counter projects using arduino that you could borrow from. Also I'm pretty sure that the AD9850 module outputs a square wave output of the generated signal along with the sine wave output so that is the signal to use for the arduino connection via a digital input pin.
I'm a little worried that 30kHz or 50kHz might be a little bit fast for the arduino to do frequency recognition directly.
What data rate are you aiming for?
Try looking up tuned oscillators with Q of 20 to 200 with one transistor.
If you can make one tuned oscilator which goes to +-3V at 50kHz only when it recieves 50kHz, and another one which makes +-3V 30kHz only when it recieves 30kHz then you are a diode and a fet away from having a reciever for slowish digital comms. That would use two digital pins of an arduino, and both high or both low indicates an error. One but not the other is a recieved bit.
I hope this gives you ideas.
I haven't started working in a code yet, mostly because I don't really know how to do start it.
Have you gone through the tutorial section? There are a lot of code snippets help you getting started!
I'm a little worried that 30kHz or 50kHz might be a little bit fast for the arduino to do frequency recognition directly.
Need hardware timers for that - http://interface.khm.de/index.php/lab/experiments/arduino-frequency-counter-library/ -