Unused pins on Dash?


#1

Are L17,16,15 and R11,10 used or accessible from code?

Thanks


#2

R10 is reserved for system usage and should not be used.
R11 is connected to the Program button. Grounding R11 is the same as pressing Program.
L15-17 are not connected to the microcontroller and should not used.


#3

Thanks Erik,

Are there any hidden (or maybe not so obvious" gotchas with the IO pins?

I am about to submit my first project PCB and want to make sure I have not missed something important.

For instance: Any port that has Analog capability (A01, A02 etc) can accept analog input by simply setting up the pinMode in setup and using analogRead, any D0x IO pins are available by defining pinMode and using digitalRead and Write, TX0/RX0 and TX2/RX2 are available as serial ports but if I set up hardware SPI then I lose TX2/RX2 and any WUx pin can be set up to generate an interrupt to wake sleeping device on pin change?


#4

A## pins support analogRead() (pinMode() not required).

D## pins support digitalRead() and digitalWrite() (along with our own digitalToggle() if you just want to switch the output value) if you set the pin function with pinMode().

TX0/RX0 are available using Serial0.
TX2/RX2 are available using Serial2.
I use those extensively with an FTDI USB-Serial board for debugging.

For SPI, if you want to use Serial2 also, you can select ALT SPI in the Arduino IDE Tools menu, and then R13 and R14 are used instead of L06 and L08. Any D## pin can be used as chip select for SPI.

Any of the WU## pins can be used for deep sleep wakeup if configured as inputs and specified as wake up pins.

Any D## pin can be used with attachInterrupt to wake from normal (not deep) sleep.

L14 is a true analog output when used with analogWrite. All other pins marked with a P support analogWrite using PWM output.