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 Robotics / 2451
  3 sensors = 8 inputs?!
 
To further the thread on the limitations of having only 3 input sensors: One of the first things that occurred to me was that three inputs gives you 3 bits of input, which means up to 8 sensors. Depending on which sensors trigger, you convert that (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: 3 sensors = 8 inputs?!
 
(...) Couldn't you do this by simple wire connections? Let's pretend you had a LOT of the motor/sensor connector wires: Sensor #1 is connected to input port #1 hit = 1 0 0 Sensor #2 is connected to input port #2 hit = 0 1 0 Sensor #3 is connected to (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: 3 sensors = 8 inputs?!
 
This would be just fine for digital (on/off) inputs. But it would not do at all for getting more analog inputs. (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: 3 sensors = 8 inputs?!
 
Mark Crosbie wrote in message <199901070320.TAA020...hp.com>... (...) 3 (...) "logical" (...) This approach can be useful in some applications ofcourse, but theoretically you don't gain more information bandwith. This is because you will be able to (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: 3 sensors = 8 inputs?!
 
(...) Unless you add a bit of electronics to multiplex your sensors, use the existing three digital inputs as a mini parallel port, design a simple communications protocol and send the sensor statuses from the module to the RCX using the protocol. A (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: 3 sensors = 8 inputs?!
 
(...) The way the inputs work does not allow hooking something up to two inputs at the same time while still keeping independent use of the inputs. You would need to add at least diodes. I assume you want a pure LEGO solution, but LEGO doesn't have (...) (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: 3 sensors = 8 inputs?!
 
In article <36945987.18CE@sr.hp.com>, Brett Carver <lugnet.robotics@lugnet.com> writes (...) Do that and you have shorted all three sensors together! (25 years ago, 7-Jan-99, to lugnet.robotics)
 
  Re: 3 sensors = 8 inputs?!
 
Mark, It has been figured out how to get four touch sensors per input. This gives 12 touch sensors if all three inputs are used. Using this approach, a 16 channel Analog MUX can be hooked up. Sensing the four switch lines using Port A and the Output (...) (25 years ago, 8-Jan-99, to lugnet.robotics)
 
  Re: 3 sensors = 8 inputs?!
 
(...) Some thoughts on muxing the inputs: The rotation sensor does not mux very well. The sensor only provides analog values that are used to increment or decrement an angle counter in the RCX. If you tried to mux this you would need to change the (...) (25 years ago, 8-Jan-99, to lugnet.robotics)
 
  Re: 3 sensors = 8 inputs?!
 
(...) Yes, but using a lever based approach gives a "pure Lego" solution to the problem, which appeals to the Lego purists out there :-) Me personally, I would use the electronic approach you outlined in your email. Regards, Mark. -- Did you check (...) (25 years ago, 8-Jan-99, to lugnet.robotics)
 
  Re: 3 sensors = 8 inputs?!
 
Did not look at the rotational sensor close enough. In that case, scalling down the MUX to a 16 channel will free up PORT C. The Rotational sensor or Fiber-optic can use PORT C for rotational input. This assumes that one motor is running the (...) (25 years ago, 8-Jan-99, to lugnet.robotics)

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