Products for USB Sensing and Control
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PostPosted: Tue Apr 17, 2012 10:53 pm 
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Is it possible to get a faster output rate? I am under the impression that the output period is locked at about 25ms/40hz. The problem for me is that this adds on to all of the delays I am trying to minimize for remote vehicle control. This combined with the lack of 6V support leads me to think I now have several of these that are useless for the project at hand. My mistake in reading the specs precisely beforehand, but please let me know if I am wrong.


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PostPosted: Wed Apr 18, 2012 9:41 am 
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The output period is not locked. What are you trying to accomplish?

If you need faster response, you can disable speedRamping - this just sends your position commands to the motors immediately without any velocity ramping.

If you need 6 V, you'll need to power the servo's externally from the 1061.

-Patrick


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PostPosted: Thu Apr 19, 2012 12:18 pm 
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Can you explain how I can know or change the output period? All I am going on is what the spec said on the product page, and that other products I had seen had configurable rates up to 333hz. There wasn't anything in the api about the rate. Perhaps I just need more info. I understand that I can do external power to get 6V. What I am trying to do is get the fastest rate possible for responsive and smooth remote control of robots and cars. Its not that 40Hz would be to slow if that was the only latency, but when combining this with the camera, the network transmission of video etc, the latency of things can overlap to create less than ideal responsiveness. I'm trying to get the best technically possible responsiveness. My custom software is written in C, and I'm transmitting control data, and return video and sensor data using UDP. In essence I am doing what the hobby FPV model airplane guys are doing, only instead of specialized controllers, and analog video, my remote device is running a full linux system and data/video is transmitted with UDP. The software is open source btw (altho not yet ready to use in any easy way for this purpose). @ http://github.com/krad-radio


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PostPosted: Thu Apr 19, 2012 2:01 pm 
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The output rate is not a fixed period - because we use control transfers rather then interrupt transfers. Data is transmitted to the device immediately, and the only limiting factors are USB bandwidth and firmware busyness - I would expect that you could update the outputs at 500-2000 times/second.

-Patrick


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PostPosted: Tue Apr 24, 2012 12:35 am 
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That sounds great to me! Thanks so much!


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