 | | RE: Multiplexing 4 touch sensors on an RCX input port
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(...) Ian, Great to see that you are having success with pbForth! I have a couple of questoins: 1. Which version are you using? 2. Are there any features you REALLY wish were available? 3. Do you have any stories or code to share? Ralph ---...--- (...) (21 years ago, 10-Sep-03, to lugnet.robotics.rcx, lugnet.robotics.rcx.pbforth)
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| | Re: Multiplexing 4 touch sensors on an RCX input port
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(...) It works very well for me, with the variation that I use home-made touch sensors that are actually microswitches embedded into 2x2 blocks. That does mean you might need to debounce in software, but normally I don't bother since the inertia of (...) (21 years ago, 10-Sep-03, to lugnet.robotics.rcx)
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| | Re: Multiplexing 4 touch sensors on an RCX input port
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I have done work in this area. I chose to solve the problem to permit 4 touch sensors to be pressed in any arbitrary combination with high probability of getting the answer right :) A simple R, 2R, 4R, 8R scheme will do. I chose R = 40.2K. This is (...) (21 years ago, 10-Sep-03, to lugnet.robotics.rcx)
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| | Re: Multiplexing 4 touch sensors on an RCX input port
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(...) Good analysis. Series can work quite well as long as you know that the touch sensors are touched mutually exclusively, but you are right parallel doesn't work well. I remember trying to come up with good resistance values to do parallel, and (...) (21 years ago, 9-Sep-03, to lugnet.robotics.rcx)
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| | Re: Multiplexing 4 touch sensors on an RCX input port
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(...) While in theory, this sounds very cool, in pratice, I doubt it will work quite that well. The biggest problem will be that the standard touch sensors may not be 100% on when you press it. This means the sensor itself can provide some (...) (21 years ago, 9-Sep-03, to lugnet.robotics.rcx)
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| | Re: Multiplexing 4 touch sensors on an RCX input port
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(...) I don't think that would work very well, as the lights have a rather low resistance, lower than a pressed touch sensor ((URL) as a purist you can use the cybermaster sensors to multiplex three inputs ((URL) Jürgen Stuber <stuber@loria.fr> (...) (21 years ago, 9-Sep-03, to lugnet.robotics.rcx)
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| | Re: Multiplexing 4 touch sensors on an RCX input port
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(...) LEGO purists use LEGO light bricks as resistors. I created potentiometer bricks, where the resistance is variable for each brick. Two stacks of 4 potentiometer bricks can be seen to the left of the RCX. In this case each stack puts the (...) (21 years ago, 9-Sep-03, to lugnet.robotics.rcx)
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| | Multiplexing 4 touch sensors on an RCX input port
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You can use four touch sensors per input port on the RCX. The Cybermaster touch sensors have resistors in parallel, and this is how the Cybermaster knows which implement is attached to the tracked robot. It uses its sensor input as a temperature (...) (21 years ago, 5-Sep-03, to lugnet.robotics.rcx)
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| | RE: leJOS & BricxCC news
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(...) OK, I've looked at your wish list and have the following comments with respect to how I see the pbForth implementation of DCC. 1. How important is it to have more than one port with DCC capabilities. The reason I'm asking is that it "would be (...) (21 years ago, 7-Sep-03, to lugnet.robotics.rcx, lugnet.trains, lugnet.robotics.rcx.pbforth)
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| | Re: USB Tower Performance [was leJOS/BricxCC news]
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(...) Doh! I forgot about Odd parity and the USB tower. I will see about fixing that little problem. Is your quad speed boot loader source significantly different from Kekoa's fastdl.s (with the parity disabling code removed)? I'd like to see it if (...) (21 years ago, 7-Sep-03, to lugnet.robotics.rcx)
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