 | | Rotation Sensors - slightly dissapointed...
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Hi, Last Friday I recieved in the mail the two Rotation Sensors I had ordered from Shop at Home 8 days earlier from the US (talk about fast delivery! I'm in Ontario). After hearing everyone tell me how wonderful they are and that they do not loose (...) (25 years ago, 16-Feb-00, to lugnet.robotics)
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| | Re: Rotation Sensors - slightly dissapointed...
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(...) If you get legOS and the patch I recently posted you won't see this problem unless you go over about 1000RPM. --Ben (25 years ago, 16-Feb-00, to lugnet.robotics)
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| | Re: Rotation Sensors - slightly dissapointed...
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<<I did discover that the sensors are horribly unpredictable and loose about 2 counts per minute when rotating continuously>> How did you test that? Stefan (25 years ago, 17-Feb-00, to lugnet.robotics)
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| | Re: Rotation Sensors - slightly dissapointed...
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Stefan Elsner wrote in message ... (...) I cannot remember if it is apporpriate to post code here (off topic, perhaps? <shrug>) but otherwise I would show you what I've done. For this purpose I had the motor rotating the sensor to about 64 and then (...) (25 years ago, 17-Feb-00, to lugnet.robotics)
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| | Re: Rotation Sensors - slightly dissapointed...
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(...) I believe there are subtropics in www.lugnet.com/lugnet.robotics for posting code. (...) (25 years ago, 17-Feb-00, to lugnet.robotics)
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| | Re: Rotation Sensors - slightly dissapointed...
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Did you have a ClearSensor() after every rotating back to 0? Stefan Rebel Transcanner <hendryjr@oxford.net> wrote in message news:Fq3Cz4.1so@lugnet.com... (...) 0, (...) (25 years ago, 24-Feb-00, to lugnet.robotics)
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| | Re: Rotation Sensors - slightly dissapointed...
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Stefan Elsner wrote in message ... (...) ...No, and that wouldn't do any good, because the error occurs before it returns home - and if it's already at 0 (home) then clearing it isn't going to make it any "homier" (^: The only practical solution I (...) (25 years ago, 24-Feb-00, to lugnet.robotics)
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| | Re: Rotation Sensors - slightly dissapointed...
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I think that motors need time to stop. If you rotate a motor backwards until the Sensor shows 0, then turn it off, it might go to -2 until it is fully stopped. So if you do a ClearSensor() afterwards your motor is off by two counts and your code (...) (25 years ago, 25-Feb-00, to lugnet.robotics)
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| | Re: Rotation Sensors - slightly dissapointed...
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Stefan Elsner wrote in message ... (...) I developed a vector-based code in which I set a variable to the location I want the motor to spin to, and mount the sensor directly on the gearmotor. The idea is I can implement this code into any of my (...) (25 years ago, 25-Feb-00, to lugnet.robotics)
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| | Re: Rotation Sensors - slightly dissapointed...
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(...) Because the LEGO Rotation sensor is a powered type, it might be slightly sensitive to battery voltage. I wonder if you notice the skipping is worse with older batteries. Also, the problem might be aggravated by long wires. Does the skipping (...) (25 years ago, 25-Feb-00, to lugnet.robotics)
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| | Re: Rotation Sensors - slightly dissapointed...
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Michael Gasperi wrote in message ... (...) while (...) I was using an AC adaptor and no long wire (just the small ~15cm cable connected right to the port). Iain -- tokama (URL) UIN 5362826 AIM Linjerflyg h e n d r y j r AT o x f o r d DOT n e t (...) (25 years ago, 25-Feb-00, to lugnet.robotics)
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| | Re: Rotation Sensors - slightly dissapointed...
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(...) If you check the legOS group you can see my posts with some extensive analysis of the sensor values for the rotation sensor. There is a patch to make legOS less sensitive to voltage fluctuations and one to debounce the input (which is what (...) (25 years ago, 25-Feb-00, to lugnet.robotics)
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| | RE: Rotation Sensors - slightly dissapointed...
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(...) Ben, I have to go back over the changes, but does legOS sample at the same rate as the standard firmware? The standard rate is about 333hz, so debouncing would likely reduce the effective rate to 166hz, which limits the max rate at which the (...) (25 years ago, 25-Feb-00, to lugnet.robotics)
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| | Re: Rotation Sensors - slightly dissapointed...
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(...) analysis (...) legOS (...) is (...) would (...) I believe it is. I tried setting the sampling rate to high speed and it just didn't work at all. Yes, debouncing the input halves the effective clock frequency, but the problem is that (...) (25 years ago, 27-Feb-00, to lugnet.robotics)
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| | Re: Rotation Sensors - slightly dissapointed...
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I've used old mouse rotation sensors in non-lego projects with some success. They employ a laser counter. The device can be easily connected to a basic stamp. If the counter disk is sealed against contaminantion it works well. Robb, ----- Original (...) (25 years ago, 28-Feb-00, to lugnet.robotics)
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| | RE: Rotation Sensors - slightly disappointed...
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Mmmm, your triggering some thoughts. A mouse is a pretty simple (serial) device Imagine having a robot which has a mouse-ball in a DUPLO block carried over the surface In this way you could record the path the robot has taken. Doing a bit of (...) (25 years ago, 29-Feb-00, to lugnet.robotics)
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