Helium ‘Atom’
Helium Systems INC., IEEE 802.15.4 Module
Preliminary Datasheet
OVERVIEW
The Atom is a dual band FCC, ETSI and IC certified
IEEE 802.15.4 module. It operates in the 2.4GHz and
915MHz bands in North America and 2.4GHz and
868Mhz bands in Europe. The module is also capa-
ble of supporting China frequencies.
The module is designed to provide wireless con-
nectivity to the Helium network infrastructure via
modular certification into an end customers applica-
tion. This allows for ease of integration for connect-
ing devices to the internet. It is perfect as a drop-
in module to add certified wireless capability to an
end product or as a stand-alone wireless device. The
module contains one chip antenna for each oper-
ational band within it’s allowed region. Those chip
antennas for 868MHz/915MHz bands have a gain of
-1.0dBi and the chip antenna for 2.4GHz has a gain
of -0.5dBi. The Atom also supports U.FL connec-
tors for external antenna connections for use with
any choice of antenna provided their performanc-
es don’t exceed the certified dipole antenna gains
of 3dBi (868MHz/915MHz) and 2.3dBi (2.4GHz). The
system exhibits -110 dBm sensitivity in the 863MHz-
870MHz and 902Mhz-928MHz bands using BPSK
modulation at 40kbps and -104 dBm sensitivity in
the 2.405GHz-2.480GHz band using O-QPSK at
250kbps. The Atom-AM is FCC/IC certified for TX
power up to +25dBm in the 915MHz band offering 10
channels and +14 dBm in the 2.4GHz band offering
15 channels for North America. The Atom-EU is ETSI
certified for TX power up to +8 dbm in the 868Mhz
band offering 8 channels and +7 dBm in the 2.4Ghz
band offering 15 channels for Europe.
The RF sections (IEEE802.15.4 transceivers) of the
module are powered by Atmel’s integrated Cor-
tex-M0+ ATSAMR21G18A (which integrates an
AT86RF233 die), AT86RF212B and SkyWorks FEMs
(PA/LNAs). This combination of radios, microcon-
troller and FEMs marries the best of the available
technologies to derive the best RF performance,
power, current consumption and cost into a 20x20
mm agency-certified module.
The module comes with pre-programmed firmware,
allowing easy setup and deployment on the Helium
wireless network. User interface is via standard UART
interface, with a well-defined and simple API.
© Helium Systems Inc. USA 2015 01/2015
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Features
Certifications
Modular certification
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ETSI (this is a different part number from the FCC/IC version)
FCC (Modular certification)
IC (Modular certification)
CE / RoHS compliant
Operational Bands
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2.4 GHz IEEE802.15.4 (all regions)
915MHz IEEE802.15.4 (North America version)
868MHz IEEE802.15.4 (European version)
780MHz IEEE802.15.4 (China WPAN version)
TX Power
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ETSI
o
TX Power 2.4GHz +10 dBm
o
TX Power 868 MHz +13.9 dBm
FCC/IC
o
TX Power 2.4GHz +14 dBm
o
TX Power 915MHz +27 dBm
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RX Sensitivity
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-104 dBm, 2.4GHz band
-110 dBm, 868/915MHz bands
Current Consumption
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RX current
o 39 mA, both radios active
o 24 mA, 2.4GHz Band only
o 23 mA, sub-GHz Band only
TX current
o 85 mA @ +10 dBm (2.4GHz, ETSI)
o 155 mA @ +13.9 dBm (868MHz, ETSI)
o 100 mA @ +14 dBm (2.4GHz, FCC/IC)
o 380 mA @ +27 dBm (915MHz, FCC/IC)
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Voltage Range
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2.0 to 3.6 V (3.3V typical; 2.4V recommended minimum for full TX power at 915MHz)
Temperature Range
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-40° to +85°C
Interfaces
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UART command interface
SWD (Serial Wire Debug) for loading user-defined firmware
One 12-bit ADC channel
Up to 13 digital GPIO
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Table of Contents
1. Introduction
1.1 Module Interface
1.2 Circuit Description
1.3 Power Management
2. Pin Configuration
3. Specifications
4. Product Development
5. System Integration
6. Electrical Characteristics
7. Operating Conditions
8. Soldering Information
9. Package Drawing - 40LGA
10. Placement on the PCB
11. Ordering Information
Appendix A Additional Information
A.1 Modular Collocation Approval
A.2 End Product Labeling
A.2.1 Countries Covered by ETSI (EU)
A.2.2 USA and Canada
A.2.3 Note
A.3 FCC Interference Statement
FCC Cautions
A.4 IC Statements
A.5 OEM Responsibilities to comply with FCC and Industry Canada Regulations
A.6 RoHS Compliance
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1. Introduction
The Atom™ is a low cost, easy to use, dual-band RF communication module for
IoT-enabled wireless products. It enables designers to easily and quickly add
wireless connectivity simply by supplying 3.3V and a UART port, and leveraging
the compact Helium Systems API. Since the module is already FCC, ETSI and IC
certified, there are no complex RF compliance issues to deal with. Its dual-band
support ensures that your product can reach the Helium network under almost all
operating conditions.
1.1 Module Interface
The primary interface to the embedded designer is through the UART. The UART
settings are 115.2K baud, 8N1. Set up your UART for either polling or interrupt on
data, and the module will effortlessly deliver received frames to your host proces-
sor.
When powered on, the module will automatically establish a secure connection
to the Helium network. No commissioning procedure is needed, and security is
hardware-based for robustness.
1.2 Circuit Description
The Atom™ incorporates the Atmel SAM R21 processor, which is an ARM Cor-
tex-M0+ class processor running at up to 48MHz. This processor includes a
stacked-die Atmel AT86RF233 2.4GHz IEEE 802.15.4 radio. An external SkyWorks
front-end chip (PA/LNA/switch) is used to permit internal/external antenna selec-
tion and to boost RF performance. An Atmel AT86RF212B 780/868/915MHz IEEE
802.15.4 radio chip is also connected to the processor, along with an additional
SkyWorks front-end chip. On-board chip antennas are supplied for each band,
as well as U.FL connectors for external antennas. All controllable aspects of radio
performance are managed by firmware in the processor. Several I/O signals
are available for interfacing to the user’s system, primarily for communicating
commands and data but also permitting general-purpose analog and/or digital
interfacing. No control signals that could directly affect the radios are available
externally.
A separate hardware security chip is also available to the processor. This chip
securely stores encryption keys as well as permanent device configuration details
(serial number, operating bands, model number, MAC addresses, etc.) and also
provides secure authentication and random number generation.
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1.3 Power Management
There are a number of factors which contribute to power consumption by the
module. Almost all of these can be controlled via firmware in order to minimize
power consumption. Here is a list of the factors:
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Transmit power setting
LNA enable/disable (may not be needed if the received signal is strong)
Both vs only one radio being active
Use of external antenna(s) (potentially higher gain than the chip antennas)
Use of module I/O signals (no pins left floating, not driving high-current
loads, etc)
CPU power management (bus/clock speeds, peripheral use, Sleep mode use,
etc)
Helium-supplied firmware endeavors to minimize power consumption both in the
CPU configuration choices and by automatically managing the radio system pow-
er, taking advantage of the network’s ability to monitor and adjust both inbound
and outbound RF path characteristics.
2. Pin Configuration
There are several GPIO signals available to the embedded designer. The figure
below shows a top side view of the module with the relative placement of the ma-
jor IO and components. (Note: the pads shown below indicate relative position,
but are on the bottom of the PCB.)
© Helium Systems Inc. USA 2015 01/2015
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RF/无线
