Hey guys,
this is my first post here and i dont know how to start a new thread but this is as close of a topic as i could find to what my question is.
I have started a project that size matters so i got Arduino mini and all i need to do it have it communicating with another Aurduino mini via xbees. Now i also need to be able to know how long it takes for signal to be sent and back and considering they are max 50 ft apart, that will bring the time down to ns, which internal timer on Arduino wont be able to do it.
Now i found these external counter IC that goes to 4.91 GHZ that i think is fast enough:
http://export.farnell.com/linear-technology/ltc6946iufd-2-pbf/pll-synthesizer-4-91ghz-3-45v-qfn/dp/2082320
now two questions:
- can i even use this knowing the "brain" clock is only going at 16 MHZ or whatever? thats slower than the external clock..
- from my understanding i can wire this up to Arduino mini and based on question 1 answer, it could work?
Thank you in advance,
Moderator edit: topic split
Sia
Hard to say, I clicked on the link and I get a list of countries not that device...
As far as I can tell, that is not a counter. It is a radio frequency generator.
Pete
Rather than muck about with semantics, why don't you explain exactly how you think you're going to use this "counter"?
Pete
it starts when the message is sent from one station. message is received and immediately sent back from second station. then as soon as it is received by first station the timer stops then i divide the time by 2 to see how long it took for it to travel.
Can you expand on your technique please?
It is possible we'll be able to save you a wild goose chase.
I have started a project that size matters so i got Arduino mini and all i need to do it have it communicating with another Aurduino mini via xbees. Now i also need to be able to know how long it takes for signal to be sent and back and considering they are max 50 ft apart, that will bring the time down to ns, which internal timer on Arduino wont be able to do it.
I've never used an Xbee, or done anything that time-critical with the Arduino, so this just my intiuition... I don't think the distance has anything to do with it, and I suspect it's going to be a LOT slower than you think... You are not just bouncing a signal off the wall...
For example, let's say we are 50ft apart and I ask you, "Can you hear me?" It takes about 50mS for my question to reach you, and about 50mS for the answer to return. But that doesn't matter, because it takes much longer to ask the question, for you to process/understand the question and respond, and for me to process/understand the answer.
What sort of accuracy are you expecting?
The UARTs sampling alone could introduce an error of many tens of metres.
I'd do just about anything I could to eliminate the Arduino from the time-critical parts of your project.
Use it to read and display results.