 | | Multiplexing Input Circuit
|
|
I think Sven thought of this first. Anyway I threw a circuit together last night that uses the SetSensorType to switch between 4 inputs. I put it on a page at: (URL) seems to work well, but startup is a problem. It starts out on input 1 but if you (...) (26 years ago, 12-Nov-98, to lugnet.robotics)
|
| |
| | Re: Multiplexing Input Circuit
|
|
(...) Require it to be clocked every so often, reset if it is held high for a certain length of time. Alternatively, it may be possible to drop the voltage to zero - but that would require a firware change... anyway, I'll look into it out of (...) (26 years ago, 12-Nov-98, to lugnet.robotics)
|
| |
| | Re: Multiplexing Input Circuit
|
|
(...) Looks good! How about using the third input port to assert the reset line and set the counter back to zero? Is your counter set up as a binary counter? From your diagram it looks like there are times that more than one sensor would be active (...) (26 years ago, 12-Nov-98, to lugnet.robotics)
|
| |
| | Re: Multiplexing Input Circuit
|
|
(...) The counter is a CMOS decade counter that has only one output high for each count. There is only one analog switch on at a time. The counter is reset when it hits the value 5 so it jumps back to 0 to start over. The analog switch is (...) (26 years ago, 12-Nov-98, to lugnet.robotics)
|
| |
| | Re: Multiplexing Input Circuit
|
|
(...) The setup I was using was bi-directional too, I'm not sure exactly why I was seeing it, but I remember getting a high reading for a non-pressed touch sensor when the next one over (the previous one in the cycle?) was pressed. If I reversed the (...) (26 years ago, 12-Nov-98, to lugnet.robotics)
|
| |
| | Re: Multiplexing Input Circuit
|
|
A simple RC circuit will work for the reset. In your code, make the first time you turn on power to the sensor delay a little longer, and the delays between subsequent readings short. I was discussing this with a co-worker, and the possibilities of (...) (26 years ago, 13-Nov-98, to lugnet.robotics)
|
