GEM 2 Module Hardware Integration Guide
Version 0.1
Wahoo Fitness
7
90 West Wieuca Road, Suite 110
Atlanta, GA 30342
www.wahoofitness.com
1‐877‐978‐1112
Pin Definitions
Pin number
Pin Name
Function
Comment
0
GND
Connect to GND Plane
1
GND
Connect to GND Plane
2
SPI Enable
SPI mode enable
3
LED
GPIO to trigger LED for
pairing/connection
indication
Active High
4
Programmable I/O
ADC or GPIO
5
Programmable I/O
ADC or GPIO
6
Programmable I/O
ADC or GPIO
7
Programmable I/O
ADC or GPIO
8
NC
9
NC
RESERVED
Reserved for 32kHz
crystal if a real time
clock is needed during
module sleep
10
NC
RESERVED
Reserved for 32kHz
crystal if a real time
clock is needed during
module sleep
11
NC
12
PAIR
GPIO to trigger
advertising
Active low
13
UART TX/SPI MISO
Host interface
14
UART RX/SPI MOSI
Host interface
15
NFC1
NFC antenna input 1
16
NFC2
NFC antenna input 2
17
GND
Module Power Ground
18
VCC
Module Power Supply
19
UART CTS/SPI Slave
Event
Flow control
20
UART RTS/SPI SS
Flow control
21
GPIO/SPI SCLK
GPIO or SPI Clock
22
RESET/SWDIO
Debug Interface
23
SWCLK
Debug Interface
24
Wake
Wakes module from sleep
25
RESET
Module Reset
26
GND
Connect to GND Plane