Feasibility for fractional duty cycle 2MHz PWM

RuggedCircuits:
Also note that a 1ns "pulse" implies the edges are themselves faster than the overall pulse. A good rule of thumb is no worse than 1/3+1/3+1/3, so 1/3 of the 1ns pulse is a rising edge, 1/3 of the pulse is steady high, 1/3 is a falling edge. This implies your rising/falling edges take no more than 300ps.

This is not easy.

You need to work with someone here who really knows what they're doing. This extends to the other parts of your circuit. Whatever you're doing with that 1ns pulse, you can't just assume it's going to be a perfect pretty little thing. Signal integrity throughout your proof-of-concept is going to be very important.

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BeatVox: inexpensive sound shield for Arduino, 3.5mm stereo output, 512Kbyte FLASH

Great point but my triggered device has a 20-60 pSec trigger window. should be 5 times higher than that @ 300 pSec.

undeRGRound:

RuggedCircuits:
Also note that a 1ns "pulse" implies the edges are themselves faster than the overall pulse. A good rule of thumb is no worse than 1/3+1/3+1/3, so 1/3 of the 1ns pulse is a rising edge, 1/3 of the pulse is steady high, 1/3 is a falling edge. This implies your rising/falling edges take no more than 300ps.

This is not easy.

You need to work with someone here who really knows what they're doing. This extends to the other parts of your circuit. Whatever you're doing with that 1ns pulse, you can't just assume it's going to be a perfect pretty little thing. Signal integrity throughout your proof-of-concept is going to be very important.

--
BeatVox: inexpensive sound shield for Arduino, 3.5mm stereo output, 512Kbyte FLASH

Great point but my triggered device has a 20-60 pSec trigger window. should be 5 times higher than that @ 300 nSec.

It may be that my 2nd level output may be shortened below 1 nSec and may necessitate longer PWM pulse to compensate?

Does this bbs have PM's, Rugged?

Yup, just click on the user's name on the left side.

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Beat707: MIDI drum machine / sequencer / groove-box for Arduino

PM sent

Like your ruggeduino :wink:

once I get my project Open Source protected.

I thought open source gave you no protection!
With open source you agree that anyone can do anything with your circuit / software. That includes make it, make money with it, sell it, just anything.
If you want some protection then open source is not the way.

Protection is only as strong as the bank roll you give to lawyers to protect it. It's like a game of poker, if a big boy comes along you will have to fold because you can't afford to put up. That applies to patents as well.

Grumpy_Mike:

once I get my project Open Source protected.

I thought open source gave you no protection!

Sorry, I left out copyright protected then OS.
Lawyers are still a necessary evil ]:slight_smile: unfortunately.

OK Guys, which Arduino model has the 16MHz PWM???
I thought it was the UNO but in radio shack I froze...
Which one to buy?

TIA!
Robert

undeRGRound:
Sorry, I left out copyright protected then OS.
Lawyers are still a necessary evil ]:slight_smile: unfortunately.

I'm not sure what you think Open Source means, but it is not a way of securing your IPR. If anything, it is the opposite: making something Open Source generally means relinquishing control over the IPR. I think this is usually done in the hope that the benefits of having people collaborate on your project outweigh the cost of revealing your technology to the competition.

The copyright/OS route is well established for this type of thing.
Not locked into ANYTHING yet, still checking it out.
My main Q right now is which Arduino to buy?
Will the RUGGEDUINO do it as well???
tia
Robert

You may be able to find 20 MHz Arduino's already assembled or you can build a kit using a 20 MHz crystal and a 20 MHz 328P or other ATmega.

I'm a bit surprised you don't go with an ARM running at 400+ MHz.

I am looking at the ARM stuff too. I need this flexibility to fully explore
the experimental aspects of the device, and once I have that data I
can then set the parameters in a "safe" zone for the hardware.

My main Q right now is which Arduino to buy?

There is no arduino you can buy at the moment to do this. The Due will probbly be able to do this but it is not out yet.
Look at the Discovery board from ST.

well I bought a RUGGEDUINO and cannot get the driver to install.
Think the board is wacked, everything seems OK until I specify the
proper driver and it refuses to recognize it... =(

FIXED the driver problem, learning the ropes now.

Guess I need a breadboard shield and/or ribbon cables to plug into
my existing breadboard. As for sample programs, I will check that
SOON. Gonna trigger a MOSFET with a PWM.

Grumpy_Mike:

My main Q right now is which Arduino to buy?

There is no arduino you can buy at the moment to do this. The Due will probbly be able to do this but it is not out yet.
Look at the Discovery board from ST.

Is that STMicro Mike?
TIA

Yes it is. It cost anywhere between free and £10
But it is a whole diffrent ball game than the arduino, it is much more complicated.

I found it. Good looking ARM. FAST
Looks like I could get 6 nanosecond resolution

Thx Mike!

As was pointed out earlier the STM chips are more difficult to use but, here is the easiest solution that I have found. Maple | LeafLabs

They use a IDE that is close to the same as Arduino but, the libraries are not well established yet. If you just need fast pin action then a STM32 chip may do the trick.

In there forum, someone has made the IDE work with the discovery boards but, I have not figured out the process of doing so yet. http://forums.leaflabs.com/

I saw that 72MHz MAPLE, looked like a nice setup?
I appreciate all this help, I really need TIME to code.
Actually learn code 8)