Available PWM Pins for use with sensors?

[Anonymous]

Hello! I notice that based on the schematic found on sparkfun’s page it seems that all the pwm pins are used except for 5 and 10. I would like to connect an RGB LED but I would need a total of 3 pins. How would this be possible. I have no need for midi (Pin 9) could I somehow make that available for my sensor/led? Thanks!

[Anonymous]

I meant pin 3 not 9***

[Michael P. Flaga]

Yes, you could you cut SJ2 or remove D13 from the SFE MP3 shield, freeing D3, from the VDSP’s UART’s RX pin. Where this signal is safely pulled up, as to make it idle. Note that in the code D3 is not actually implemented. So again it is available, for you to use. I believe I have done this before for PWM to drive IR LED’s.

You want to cut the VDSP’s UART RX pin is principally for MIDI commands but it also can be used for other items. Hence it is wise to severe the PWM’s output to this, as not to cause superfluous UART data to the VDSP.

Similiarly D4 can be recovered, by cutting SJ1 or removing R14, to get another Digital IO

[Anonymous]

Thank you! I ended up only needing PWM Pin 3, so I just carved off the pull up connection. If I ever need MIDI I can just solder the two silver squares together again. The only reason I wanted to disconnect it was, because even though I’m not using midi, the pull up kept my connected LEDS on, when idle, now they’re completely off. Thanks!

[Author]

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