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Unread 13-02-2004, 15:15
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Al Skierkiewicz Al Skierkiewicz is offline
Broadcast Eng/Chief Robot Inspector
AKA: Big Al WFFA 2005
FRC #0111 (WildStang)
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Re: Line sensor wire gauge questions

Quote:
Originally Posted by Dinush

And in the rule book it says:


"I was also unsure because I soldered the blue wire in the line sensor to a PWM pin which connects to the Digitali I/O ground, but in the circuit diagram, it shows the line sensor connecting directly to the ground on the circuit breaker." The blue wire can go to the ground pin on the RC or to battery common. I found it easier (and more correct for signal) to connect to the RC Ground Pin.

"Sensors may not be wired in series with their loads to directlyu control those loads"
This is to prevent high current from passing through or being controlled by low current devices. It is for your own safety that Banner sensors be used with inputs on the RC and not connect directly to any motor or solenoid.

"Which is why I was wondering about running one wire from the 20amp circuit breaker and cutting off parts off the insulation and sodering the brown wire of each sensor to the +12V wire."
The brown wire is the +12 volt input to the sensors. You could run a wire from the +12 volt input to the RC for this purpose but I would not. The separate wire and circuit breaker is the best approach. The circuit breaker protects your wiring for the sensors and won't affect the operation of the RC. Again, don't forget to adequately insulate your soldered connections when they are complete.

"It also says:
"The loads must be controlled by PWM signals sent by the Robot Controller to relays or speed controllers. What exactly is this reffering to? Does this mean that the power of the sensors has to be controlled by the microcontroller through a relay?"
It means that any motor, solenoid or servo must be controlled by speed controller or Spike only. Since these devices can only be controlled by the RC, then all sensors must be used as inputs to the RC and software must be used to read those inputs and respond with a PWM output to control any of the output devices listed above.

Final note: The Banner sensors have normally open and normally closed contacts which reference to the common or "blue" lead. Your software and connection must match for proper operation. i.e. when the software expects a closure to ground, the sensor is wired with the black lead to the signal input on the RC. Check your software as it controls some of the digital inputs for other functions. (or so I have been told, any software guys can comment on that.)
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Good Luck All. Learn something new, everyday!
Al
WB9UVJ
www.wildstang.org
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Storming the Tower since 1996.

Last edited by Al Skierkiewicz : 13-02-2004 at 15:23.