NORTHPOLE GEM3NFC User manual

North Pole Engineering © North Pole Engineering Inc. 2020
221 N 1st St, Minneapolis, MN 55401
www.npe-inc.com
612.305.0440
GEM3NFC
Hardware Manual
Version 1.0
August 31, 2020
NORTH POLE ENGINEERING INTELLECTUAL PROPERTY
THIS DOCUMENT IS INTENDED FOR USE BY APPLICATION DEVELOPERS TO
CREATE APPLICATIONS COMPATIBLE WITH THE NORTH POLE ENGINEERING
GEM MODULE. USE OF THE TECHNICAL INFORMATION CONTAINED IN THIS
DOCUMENT TO CREATE COMPETING HARDWARE TO THE NORTH POLE
ENGINEERING GEM MODULE IS STRICTLY PROHIBITED.

Revision History
Version
Revision Date
Change History
0.1
October 2, 2019
Initial draft
0.2
October 30, 2019
Added mechanical drawing
0.3
April 13, 2020
Added UART connection note,
added power consumption data
for different modes
1.0
August 31, 2020
Added current consumption
information and I2C interface
details

North Pole Engineering © North Pole Engineering Inc. 2020
221 N 1st St, Minneapolis, MN 55401
www.npe-inc.com
612.305.0440
Table of Contents
Revision History......................................................................................................................................2
Overview and Key Features ................................................................................................................4
Features................................................................................................................................................................ 4
Specification.............................................................................................................................................6
Specification Summary................................................................................................................................... 6
Hardware Specifications......................................................................................................................7
Block Diagrams.................................................................................................................................................. 7
GEM3NFC Overview ...............................................................................................................................9
Overview .............................................................................................................................................................. 9
Data, power, & I/O connector ...................................................................................................................... 9
Additional I/O ..................................................................................................................................................10
NFC Reader........................................................................................................................................................10
NFC Antenna.....................................................................................................................................................10
GEM3 module ...................................................................................................................................................10
Specifications........................................................................................................................................ 10
Operating Parameters...................................................................................................................................10
GEM3NFC Considerations ................................................................................................................. 12
Antenna Characteristics...............................................................................................................................12
Mechanical Information.................................................................................................................... 13
Dimensions (in mm)......................................................................................................................................13
Connecting GEM3NFC to Console MCU ......................................................................................... 13
GEM3NFC Host Protocol .................................................................................................................... 14
NFC Reader T4T card mode operation......................................................................................... 14
ISO/IEC 1444A card mode ..........................................................................................................................14
ISO/IEC 14443B card mode........................................................................................................................15
Regulatory & Standards Information........................................................................................... 15
FCC & Industry Canada.................................................................................................................................15
Federal Communication Commission (FCC) Radiation Exposure Statement: ...................15
FCC Labeling Requirements...................................................................................................................16
FCC Warning:...............................................................................................................................................16
Industry Canada (IC) Warning:.............................................................................................................17
CE ..........................................................................................................................................................................19
Bluetooth Qualification.................................................................................................................................19
Ordering Details................................................................................................................................... 20
Further Assistance .............................................................................................................................. 20

GEM3NFC Hardware Manual
Overview and Key Features
The GEM3NFC module is been designed to allow OEMs to easily add Bluetooth, ANT+, Apple
GymKit, Samsung Galaxy Active/Active 2 and NFC reader connectivity in their product
offering.
The GEM3NFC module is based on Nordic Semicondutor’s nRF52840 multi-protocol
Bluetooth and ANT+ chipset and integrates NXP’s PN7150X NFC reader controller. There is
also space on the board for the Apple authentication 3.0 coprocessor to be mounted for
applications where Apple GymKit support is needed. The GEM3NFC module offers a serial
host interface and has a maximum transmit power of +8dBm, and a sensitivity of -95dBm.
This manual is intended to assist with hardware integration of the GEM3NFC module into a
given design. Details on North Pole Engineering’s GEMHCI protocol software can be found
at http://npe-inc.zendesk.com.
Features
•-95 dBm sensitivity
•TX Power-20 to +8dBm in 4dB steps
•240m line of sight range @ +8dBm
•15 mA peak TX @ 8dB, 6.2mA @ 0dBm
•4.6 mA peak RX
•1dB dB RSSI resolution
•ARM® CortexTMM4F 32 bit processor running at 64MHz
•1MB embedded flash memory and 256 kB RAM
•Serial Host Interface
•I2C Interface
•AES HW encryption
•FCC, CE, IC certified
•Integrated Bluetooth, ANT, and NFC antennas
•RoHS compliant
•Bluetooth End Product Listed
•Integrated GEMHCI software
•Integrated support for ANT+ FE and Bluetooth FTMS
•ANT+ and BLE HRM scanning and connection

North Pole Engineering © North Pole Engineering Inc. 2020
221 N 1st St, Minneapolis, MN 55401
www.npe-inc.com
612.305.0440
•Integrated NFC tap to pair support for wearables including Apple Watch through
GymKit and Samsung Galaxy Active/Active2 Watches.

Specification
Specification Summary
Category
Feature
Implementation
RF
Bluetooth
ANT+
Frequency
Maximum Transmit Power
Minimum Transmit Power
Receive Sensitivity
Range
5.0 Single Mode Peripheral and Central
Broadcaster and receiver
2.402-2.480 GHz
+2dBm
-20dBm
-95dBm
up to 360m line of sight
NFC
Reader
Frequency
Read/Write mode
Peer to Peer mode
Card emulation mode
Tag Type 1,2,3,4,5
13.56MHz
MIFARE, FeliCA, ISO/IEC 14443 A/B,
ISO/IEC 15893
ISO/IEC 18092 target and initiator
NFC Forum T4T
Peripherals
Serial Host Interface
I2C Interface
TX, RX 115.2kbps n,8,1
I2C Master –400Kbps
FW Upgrade
North Pole Engineering
Firmware
Over the air
SWD interface
UART Interface
Control Protocol
GEMHCI
GEMHCI binary command interface
Supply Voltage
Recommended
3.3V
Power Consumption
Less than 50mA peak
Physical
40mm x 40mm
Environmental
-40 to +85C
Approvals
FCC, IC, CE, Bluetooth EPL

Software Diagram

North Pole Engineering © North Pole Engineering Inc. 2020
221 N 1st St, Minneapolis, MN 55401
www.npe-inc.com
612.305.0440
GEM3NFC Overview
Overview
The following picture provides an overview of the various hardware elements of GEM3NFC
board.
Data, power, & I/O connector
The data, power, and I/O connector provides a means to connect a supply voltage of 3.3V to
the GEM3NFC module as well as UART TX and RX lines for serial communications between
the GEM3NFC module and the fitness equipment console MCU. The GEM3NFC UART lines
are TTL level and operate at 115.2Kbps.
NOTE: External connection to the UART TX and UART RX lines should be connected as
shown below. Connect host MCU TX to pin 10 (TX) on GEM3NFC module and host MCU RX
to pin 12 (RX) on GEM3NFC module.
The connector is JST BM14B-ZPDSS-TF(LF)(SN). The mating JST connector housing is JST
ZPDR-14V-S and is available through Digi-Key and other distributors.
Data, power, and I/O connections:
GEM3
Data, Power & I/O
NFC
Reader
NFC Tag Board ConnectorNFC Antenna

NFC Tag Board Connection
The GEM3NFC module includes an additional connector to support connection of an NFC
tag board using I2C communications. Pinout of the I2C interface is shown below:
NFC Reader
The GEM3NFC module incorporates an NFC reader chip allowing for decoding of compatible
NFC tags for user identification for example. In addition, the NFC reader also supports NFC
type 4 tag emulation for tap to pair support with compatible Android and iOS applications.
NFC Antenna
The GEM3NFC module includes an integrated NFC antenna.
GEM3 module
The GEM3NFC includes North Pole Engineering’s GEM3 Bluetooth 5.0 and ANT wireless
OEM module and includes North Pole Engineering’s embedded software specifically
designed for fitness equipment mobile app, group fitness, and wearable connectivity
applications.
Specifications
Operating Parameters
Parameter
Min
Typical
Max
Supply Voltage
3.0V
3.3V
+3.6V
Operating Temperature @ 3.3V
-40C
+85C
Serial Interface
3.0
3.3V
3.6V
1
2
3
4
5
P2
NFC TAG
GND
V3R3
TAG_I2C_SCL
TAG_I2C_SDA
TAG_FD
GND
TP3
TP4
TP5
4.7uF
C4

North Pole Engineering © North Pole Engineering Inc. 2020
221 N 1st St, Minneapolis, MN 55401
www.npe-inc.com
612.305.0440
Power Consumption
Power Mode
Average (mA)
Peak (mA)
Standby
0.890
1
NFC Polling
7
135
NFC Read & Connection
37
228
Watch Connected
2
14
BLE Only
1.5
7
ANT+ Only
1
4