Troubleshoot BeagleBone Black GPIO Pins

Error Using writeDigitalPin

Writing a logical value to a pin produces an error:

configureDigitalPin(bbb,'P8_12','input')
writeDigitalPin(bbb,'P8_12',1)

The error states that the pin being written to is configured as an input. To solve this issue:

Use a different pin number.
Use configureDigitalPin to reconfigure the pin as an output.

Error Using readDigitalPin

Reading the logical value of a pin produces an error:

configureDigitalPin(bbb,'P8_11','output')
readDigitalPin(bbb,'P8_11')

The error states that the pin being read is configured as an output.

To solve this issue, do either of the following:

Use a different pin number.
Use configureDigitalPin to reconfigure the pin as an input.

Unexpected Digital Pin Number

Using a specific pin number produces an error:

configureDigitalPin(bbb,'P8_27')

The error states that the pin is unavailable for use as a digital pin. It is possible that another interface is using the pin.

To solve this issue, do either of the following:

Use the AvailableDigitalPins property to identify which GPIO pins are available, and then use a different pin number.
Use the showPins and showAllPins functions to discover how the pin is configured. Restart the BeagleBone Black hardware to return the pins to their default configuration

Note

The hardware enables HDMI (orange) pins by default. MATLAB^® Support Package for BeagleBone^® Black Hardware does not support HDMI. To disable HDMI, see the BeagleBone Black hardware documentation.