Editing MX13 SpaceSaver Keyboard (section)

====Pin assignments====

The Teensy is wired to the keyboard matrix and additional hardware components as defined in the following tables.
Some of these pin assignments are arbitrary, while others are based on the mapping of Teensy features to I/O pins (e.g., PWM, I2C/TWI, SPI).
Note that it is best to avoid using pin D6 for the matrix columns because the Teensy wires its on-board LED to that pin, and it may interfere with the the ability to sense that column correctly with the pin in a high impedance state.

{| class="wikitable" style="border-width:0;"
|+Teensy pin assignments
|-
! Pin
! Alt. Function
! Connection
| rowspan="27" style="width:2em; background-color:#fff; border-width:0;" |
! Pin
! Alt. Function
! Connection
| rowspan="27" style="width:2em; background-color:#fff; border-width:0;" |
! Pin
! Alt. Function
! Connection
|-
! A0 
| || Matrix row 0
! B0 
| SPI SS || Display select (CS)
! C0 
| || Matrix column 8
|-
! A1 
| || Matrix row 1
! B1 
| SPI CLK || Display clock (SCL)
! C1 
| || Matrix column 9
|-
! A2 
| || Matrix row 2
! B2 
| SPI MOSI || Display data (SDA)
! C2 
| || Matrix column 10
|-
! A3 
| || Matrix row 3
! B3 
| SPI MISO || ''No connection''
! C3 
| || Matrix column 11
|-
! A4 
| || Matrix row 4
! B4 
| OC2A (PWM) || In-key num-lock LED Green
! C4 
| OC3C (PWM) || In-key scroll-lock LED Red
|-
! A5 
| || Matrix column 3
! B5 
| OC1A (PWM) || In-key num-lock LED Red
! C5 
| OC3B (PWM) || In-key scroll-lock LED Green
|-
! A6 
| || Display data/command (DC)
! B6 
| OC1B (PWM) || In-key num-lock LED Blue
! C6 
| OC3A (PWM) || In-key scroll-lock LED Blue
|-
! A7 
| || Display reset (RES)
! B7 
| OC1C (PWM) || TrackPoint LEDs
! C7 
| || ''No connection''
|- style="background-color:#fff; border-width:0;"
| colspan="3" style="border-width:0; text-align:center;" | '''Port A'''
| colspan="3" style="border-width:0; text-align:center;" | '''Port B'''
| colspan="3" style="border-width:0; text-align:center;" | '''Port C'''
|- style="height:2em; background-color:#fff; border-width:0;"
| colspan="11" style="border-width:0;" | 
|-
! Pin
! Alt. Function
! Connection
! Pin
! Alt. Function
! Connection
! Pin
! Alt. Function
! Connection
|-
! D0 
| I2C/TWI SCL || LED controller clock (SCL)
! E0 
| || Matrix column 6
! F0 
| || Matrix column 12
|-
! D1 
| I2C/TWI SDA || LED controller data (SDA)
! E1 
| || Matrix column 7
! F1 
| || Matrix column 13
|-
! D2 
| || TrackPoint PS/2 data
| colspan="3" rowspan="2" | 
! F2 
| || Matrix column 14
|-
! D3 
| || Matrix column 1
! F3 
| || Matrix column 15
|-
! D4 
| || Matrix column 2
! E4 
| || ''No connection''
! F4 
| || Matrix column 16
|-
! D5 
| || TrackPoint PS/2 clock
! E5 
| || ''No connection''
! F5 
| || Matrix column 17
|-
! D6 
| Teensy LED || ''No connection''
! E6 
| || Matrix column 0
! F6 
| || Matrix column 18
|-
! D7 
| || Matrix column 5
! E7 
| || Matrix column 4
! F7 
| || ''No connection''
|- style="background-color:#fff; border-width:0;"
| colspan="3" style="border-width:0; text-align:center;" | '''Port D'''
| colspan="3" style="border-width:0; text-align:center;" | '''Port E'''
| colspan="3" style="border-width:0; text-align:center;" | '''Port F'''
|- style="height:2em; background-color:#fff; border-width:0;"
| colspan="11" style="border-width:0;" | 
|-
! Pin
! Alt. Function
! Connection
! Pin
! Alt. Function
! Connection
! Pin
! Alt. Function
! Connection
|-
! +5V
| || Vcc for SSII controller, LED controller, and OLED display
! RST (bot)
| || External reset switch
! AREF
| || ''No connection''
|-
! GND (mid)
| || Ground for SSII controller, LED controller, and OLED display
! GND (bot)
| || External reset switch
! ALE
| || ''No connection''
|-
! GND (end)
| || TrackPoint LED ground
! VCC (bot)
| || ''No connection''
| colspan="3" style="background-color:#fff; border-width:0; text-align:center;" | '''Others'''
|- style="background-color:#fff; border-width:0;"
| colspan="3" style="border-width:0; text-align:center;" | '''Power'''
| colspan="3" style="border-width:0; text-align:center;" | '''Bottom'''
| colspan="3" style="border-width:0;" |
|}