Dc motor controll?

Question

Hi all I have finished one part of the dc motor controll program, this has subroutines for moveForward and moveBackward. There are also limit switches set up for leftLimit and rightLimit.

What I would like next is to initiate a routine by a single press of goButton. The table would then moveForward until leftLimit goes high, then stop and moveBackward until rightLimit goes high and stop and wait for next goButton to start next cycle. The problem is the goButton and both the limit switches will not stay high, they will just be high for a short time to initiate the action , but the action has to go on until the next input.

Hope I have explained this well.

Gerhard

mcb1 · Accepted Answer

Gerhard regarding the 'if' and 'while' ... It's not a lot different to switching a LED on or off using a pushbutton. Mark

mcb1 · Answer

Gerhard

Presumably you have a motor shield or similar that has a direction and ON/OFF function.

Under the loop, check for the pushbutton either using 'while' or an 'if' statement.

When you detect the switch, then set the motor direction pin, and the ON pin to start the motor.

Using another 'if' or 'while' statement, look for the limit switch.

When the limit switch is operated, then change the ON pin to stop the motor.

Change the direction and start the delay.

Set the ON to make the motor move (opposite direction).

When the limit switch is operated, then change the ON pin to stop the motor.

Change the direction.

return to the loop (exit the original 'if' or 'while' statement).

No requirement to have the switches permanent just the ability to detect them.

I would also suggest that you have the switches normally closed until pressed.

This is 'fail to safety' in that if the wire breaks, or the contact is poor, the program will assume the limit has been reached.

Mark

Dc motor controll?

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