iCommand latency

This is where you talk about the NXJ hardware related topics such as the brick, sensors, LEGO pieces, etc.

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imaqine
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iCommand latency

Postby imaqine » Wed May 30, 2007 12:58 am

I am curious what are some people's experiences with iCommand's latency issue between the time the command is called and sent on the PC side to when it is executed on the NXT side. What ways have you guys used to get around this latency issue.

The reason I ask is because I am doing research and would like to use iCommand to communicate with the NXT but the latency has been an issue when having the robot react to its surroundings. Any ideas?

breneez
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Postby breneez » Thu May 31, 2007 12:51 am

I've mostly only played around with joystick control via icommand, but I've been pretty impressed by the reaction time. Perhaps my standards are lower, or maybe the sensors are slower to react than the motors?

roger
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ICommand latency

Postby roger » Fri Jun 01, 2007 4:42 am

Yes, it is pretty long - I think because of the round trip time for the bluetooth massage and the acknowledgement.

imaqine
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Postby imaqine » Fri Jun 01, 2007 2:46 pm

Well I had wanted to control the nxt from the computer to calculate how to get through a maze, or something of that sort. The reaction time is definitely not made for 'quick' decisions that are neccessary when transversing a maze. I found myself crashing into walls because of the late reaction time.

roger
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ICommand latency

Postby roger » Sun Jun 03, 2007 4:20 am

The way to avoid crashing into walls is to put the reflex actions - the quick feed back loops from sensor to motor - into Java code running on the NXT.
I think the next release of NXJ will allow 2 way communications between java on the NXT and java on the PC so you can decide how best to split the responsibilities between the NXT and the PC.

Roger

Machiel
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Postby Machiel » Wed Oct 29, 2008 10:45 am

I am curious, How many Miliseconds is the latency?
Like.... 200 miliseconds?

Zaleekha
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icommand problem

Postby Zaleekha » Fri Apr 02, 2010 4:56 pm

I can not access the package of icommand.nxt
i can see them but when i open i found error
"icommand.nxt does not exit"


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