Pin Usage
=========

mk20dx256vlh7

 ----
|Keys|
 ----

* Strobe (Columns)

PTB2
PTB3
PTB18
PTB19
PTC0
PTC9
PTC10
PTC11
PTD0

* Sense (Rows)

PTD1
PTD4
PTD5
PTD6
PTD7
PTC1
PTC2
PTC3


 -----
|Clock|
 -----

PTA18 <-> PTA19


 ---
|I2C|
 ---

* IS31FL3731C

PTB0  - SCL0 (add header pin, label as SCL0)
PTB1  - SDA0 (add header pin, label as SDA0)
PTB17 - INTB Chip 1
PTB16 - SDB (tied to all Chips, hardware shutdown)



 ---
|DAC|
 ---

DAC0 (N/C)


 ----
|UART|
 ----

* Comm - For bi-directional communication between halves

PTA1 - RX0 (Master Side)
PTA2 - TX0 (Master Side)

PTD2 - RX2 (UART Debug Header)
PTD3 - TX2 (UART Debug Header)


 -----
|Debug|
 -----

* SWD - (Main reflash header)

PTA0 (Pull-down)
PTA3 (Pull-up)

* LEDs

PTA5 (LED only for PCB, not Teensy)

* UARTs

PTD2 - RX2 (UART Debug Header, label as RX2)
PTD3 - TX2 (UART Debug Header, label as TX2)


 ------
|Unused|
 ------

* GPIO

PTA4
PTA12
PTA13
PTC4
PTC5
PTC6
PTC7
PTE0
PTE1

* Analog

TODO