waveform generator with uno r3

The UNO itself will not be able to help you here, it only runs at 16Mhz and even with the tightest coding will probably not exceed few Mhz on any of its pins

Getting a sine wave at upto 500Mhz will require external help where the UNO would only be a controller, not the actual generator

Do you have a lower frequency limit, if you generate a square wave and use external RC/LC filtering, you could approximate the sine wave

What control do you want over it or is it just a static signal

Basically, tell us what you intend to do with it and more about how you intend the project to function… SPECS ?

The lower limit would be about 1MHz, for my assignment, i need to create a sine wave from 1MHz to 500MHz tunable using a potentiometer or a variable in the code.

Yes i intend for the UNO to be the controller so i want to know what external hardware do i need.

I also know i can use a square wave instead, but if i have no limits on what hardware i can use, how would i go about doing the same without a square wave.

Basically, i select a frequency, and that wave is generated. So is that static? As for any more specs, that is all i was given by my professor.

I am actually a major in computer science and this is my first project that involves components of computer engineering.

Do you have the equipment to measure up to 500Mhz and look at the signal to validate its integrity (I don’t for sure), maybe at the school / UNI EE Lab

A 1Ghz scope would be nice, and a frequency counter. RF is such a fun subject but one I have not delved into too much so far

If it where me then I would be looking at voltage controlled oscillator and perhaps a Phased locked loop (PLL) to up the frequency to the range desired

There are other qualified folks looking at this in the forums too that have way more RF skills than I poses so let’s see if they can provide better suggestions

Regards

Peter

Well, i know some labs in my school that have the MSO/DPO5000B Mixed Signal Oscilloscope which can be accurate up to 2GHz and 10 GS/s maximum sampling rate.

So i think it should be fine. Thanks for the direction, i shall research using VCO and PLL and perhaps wait for more folks to reply.

Cheers

Narrowing the band certainly makes it easier to have a single or at least fewer oscillators but as Shabaz stated, RF is a whole set of skills all on its own

Current wave form generators cost thousands and they may only go up to 120Mhz (I know that’s the top of mine and it would cost about 8K$)

Yours is simpler as you only want a sine wave but you have not specified at what amplitude or power and still going from 1Mhz to 200Mhz is a massive range that would not be satisfied with a single oscillator or circuit

You may want to go bac to the Prof and clarify the requirements and specifications for the part you need to build

Were happy to help but the expectations seems to be way out of your current skill set/ experience or the realm of a typical school assignment

Please try to get clearer requirements and expectations (Bigger picture view of the project would help too)

Peter

Oh, after hearing how ridiculous it sounded, i went back to check the project requirements..and realised i read the upper limit wrongly. (probably too tired)

Anyway the actual frequency needed is 1-20 MHz in 0.1 Hz increments.

As for amplitude it's not stated, i will ask my prof and see what he says.

sorry for the confusion with the extremely high frequencies.

That's much more manageable.

If you're looking for a complete custom solution:

http://datasheets.maximintegrated.com/en/ds/MAX038.pdf

that's just what i was looking for. thanks alot man.

Hope it all works out for you. That one comes in DIP so you should be able to make your circuit in perf board (vero board).

i tried to order the max038CPP from element14, mouser, digikey but all state it as obsolete.

is there any other IC i may use?

preferably a link to a element14 product.

thanks

Not as fancy, but should get the job done. You can order samples from Linear

http://www.linear.com/product/LTC1799

Edit: Wait! It's a square wave output. Unless you want to filter, we'll have to find another chip.

Not as fancy, but should get the job done. You can order samples from Linear

http://www.linear.com/product/LTC1799

Edit: Wait! It's a square wave output. Unless you want to filter, we'll have to find another chip.

There are DDS chips by Analog Devices, that will output a sine wave, but I'm not sure this is what his prof wants either. I think you may be right, it could have been a sig-gen controlled by GPIB etc.

Yup, I tend to agree too, it sound more achievable in a reasonable amount of time and perfect for a computer science student, not an EE.

Peter

Lots of people (including Analog Devices) sell Analog Devices DDS chips on little boards ready for some external control.

This was the first one I found (I have never dealt with these people so do some checking and look at other sources):

AD9850 DDS Signal Generator Module 0 40MHz New | eBay

I suggest the OP looks for others and also at AD's data on the chip.

MK

Finally found out what he wants.

He is trying to find out the effects of frequency with respect to our indoor positioning system.

My scope is to find a device that can output 1-20 MHz and for each frequency, record the readings from the RF receivers and plot it on a graph, which we will datamine.

So you are right, it was a sig gen controlled by GPIO.

Both of us are CS people and not EE so we will just follow the advice given here. He will order the AD9850 and we will see if it works.

Thanks once again.

Jeremy,

               I have used the AD 9850, others have suggested, along with an Arduino R3.  It worked without any problems using some code I found on the net, suitably modified for my needs.   There is code for a sweep generator along with AD9850.cpp and AD9850.h files on the net.  I think these will give you a basis for the frequency generator you require.  The sine waves generated at the frequencies you are interested in are good.

Bob