PWM pin on Motor Shield?
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PWM pin on Motor Shield?

by ed_devane on Sat Feb 16, 2013 12:00 pm

Hi,

I'm building a guitar pickup winder using a motor shield on top of a Mega 2560. I have a stepper motor connected to M3 and M4 ports, but otherwise am not using the shield.

I need to be able to control the brightness of an LED using PWM but all the PWM pins are connected to the shield. Is there a way of using the servo connectors to control an LED, or can I disconnect one of the arduino's PWM pins from the shield?

Cheers
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Re: PWM pin on Motor Shield?

by adafruit_support_bill on Sat Feb 16, 2013 12:08 pm

You can connect to the servo headers. Pins 9 and 10 are directly connected to the servo signal pins (the ones closest to the label).
Also, digital pins 3 and 11 are used for motors 1 and 2. If you are not using those motor channels, you can re-purpose those pins for your led control.
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Re: PWM pin on Motor Shield?

by ed_devane on Sat Feb 16, 2013 12:46 pm

thanks for the reply! If I connect an LED to the servo pins, would I connect the "-" (which I assume is earth) and the "S" pins to the LED (with resistor)?
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Re: PWM pin on Motor Shield?

by adafruit_support_bill on Sat Feb 16, 2013 1:04 pm

would I connect the "-" (which I assume is earth) and the "S" pins to the LED (with resistor)?

That is correct! :)
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Re: PWM pin on Motor Shield?

by ed_devane on Sun Feb 17, 2013 7:40 am

I actually ended up removing the terminal pin for pin 11 and drilled a 2mm hole to allow a jumper cable to go through the shield without making contact, into the arduino. Works like a charm! Thanks for the very swift responese.

ed
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