Clock Question

mollensoft

Hi Folks,
anyone know what's the highest resolution Clock I can make with the Basic Stamp (or optionally propeller)?

I am trying to build a microsecond, synchronized light/magnetic sensor array but I've noticed that keeping time between 4 sensors is pretty important to results.

Not many microsecond, sync-able clocks around (unless my google skills are inept!)

to give u an idea what an example sensor looks like (not sophisticated):
http://mollensoft.com/product2.html

Thanks for any pundancy or advice.

bigal@mollensoft.com

Post Edited (mollensoft) : 6/30/2010 1:25:02 AM GMT

Mike Green

1) Add a subject to your new thread by clicking on the pencil icon in the first message box.

2) The Stamp is really not capable of generating actions with resolution on the order of microseconds. It can produce individual actions on that order (like a single pulse or measuring a single pulse) with a resolution of 2us for the BS2 and better with other Stamp models, but the instructions themselves take on the order of 100us or more to execute and there's no detailed documentation on the exact timing.

3) The Propeller is capable of resolutions on the order of 12.5ns with an 80MHz system clock (what's usually used). With care in circuit/PCB layout, you can run the Propeller up to 104MHz which gives you a resolution on the order of 10ns.

4) Remember that cable length (propagation time) and impedance matching is important even with resolutions on the order of 1us and vital for higher resolutions.

mollensoft

Hi Mike,
thanks... I'll try the Propeller out, never hurts to learn something new [noparse]:)[/noparse]
Good advice on the propagation delay as well, I had not initially been accounting for it which, I was getting measurements that did not really line up well.

thanks again!

-Al

Mike Green

Newcomers are always welcome. All of the "experts" here started once upon a time as newcomers.

Read the forum guidelines (a thread in the announcements forum). They'll help you get the quickest and probably the best answers. Don't be timid about starting your own thread with a question, but be sure to include a subject for the thread so everybody has some idea what you're asking about. Follow the advice you're given, particularly regarding doing some research or reading. You'll learn better and more thoroughly that way. Often the same question has been asked before and there's a great discussion of it in some reference. If you don't understand the replies to your question, say so and give some idea of where you're confused.