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Particle Photon with Headers
PRODUCT ID: 2721
DESCRIPTION
The Photon is a tiny Wi-Fi development kit for creating connected projects and products for the
Internet of Things. It's easy to use, it's powerful, and it's connected to the cloud.
The tools that make up the Photon's ecosystem (and come along with the board) are designed
to let you build and create whether you're an embedded engineer, web developer, Arduino
enthusiast or IoT entrepreneur. You'll be able to write your firmware in our web or local IDE,
deploy it over the air, and build your web and mobile apps with ParticleJS and our Mobile SDK.
The board itself uses a Broadcom WICED Wi-Fi chip (one that can be found in Nest Protect, LIFX,
and Amazon Dash) alongside a powerful STM32 ARM Cortex M3 microcontroller. It's like the
Spark Core, but better! The WICED chipset is much faster than the original CC3000 in the 'Core
and also supports SSL and Soft-AP mode.
This is the Photon with breadboard headers connected.
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TECHNICAL DETAILS
Particle P0 Wi-Fi module
Broadcom BCM43362 Wi-Fi chip
STM32F205 120Mhz ARM Cortex M3
1MB flash, 128KB RAM
802.11b/g/n
Soft AP setup
FCC/CE/IC certified
Height (w/ headers): 12mm
Product Dimensions: 38.0mm x 21.0mm x 3.0mm / 1.5" x 0.8" x 0.1"
Product Weight: 5.0g / 0.2oz
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Photon Datasheet (v014)
Model number: PHOTONH, PHOTONNOH
Functional description
OVERVIEW
Particle's Internet of Things hardware development kit, the Photon, provides everything you need to
build a connected product. Particle combines a powerful ARM Cortex M3 micro-controller with a
Broadcom Wi-Fi chip in a tiny thumbnail-sized module called the PØ (P-zero).
To get you started quickly, Particle adds a rock solid 3.3VDC SMPS power supply, RF and user
interface components to the PØ on a small single-sided PCB called the Photon. The design is open
source, so when you're ready to integrate the Photon into your product, you can.
The Photon comes in two physical forms: with headers and without. Prototyping is easy with headers
as the Photon plugs directly into standard breadboards and perfboards, and may also be mounted
with 0.1" pitch female headers on a PCB. To minimize space required, the Photon form factor
without headers has castellated edges. These make it possible to surface mount the Photon directly
onto your PCB.
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FEATURES
Particle PØ Wi-Fi module
o Broadcom BCM43362 Wi-Fi chip
o 802.11b/g/n Wi-Fi
o STM32F205RGY6 120Mhz ARM Cortex M3
o 1MB flash, 128KB RAM
On-board RGB status LED (ext. drive provided)
18 Mixed-signal GPIO and advanced peripherals
Open source design
Real-time operating system (FreeRTOS)
Soft AP setup
FCC, CE and IC certified
Interfaces
BLOCK DIAGRAM
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POWER
Power to the Photon is supplied via the on-board USB Micro B connector or directly via the VIN pin.
If power is supplied directly to the VIN pin, the voltage should be regulated between 3.6VDC and
5.5VDC. When the Photon is powered via the USB port, VIN will output a voltage of approximately
4.8VDC due to a reverse polarity protection series schottky diode between V+ of USB and VIN.
When used as an output, the max load on VIN is 1A.
Typical average current consumption is 80mA with 5V @ VIN with Wi-Fi on. Deep sleep quiescent
current is typically 80uA (Please refer to Recommended Operating Conditions for more info). When
powering the Photon from the USB connector, make sure to use a quality cable to minimize IR drops
(current x resistance = voltage) in the wiring. If a high resistance cable (i.e., low current) is used,
peak currents drawn from the Photon when transmitting and receiving will result in voltage sag at the
input which may cause a system brown out or intermittent operation. Likewise, the power source
should be sufficient enough to source 1A of current to be on the safe side.
RF
The RF section of the Photon is a finely tuned impedance controlled network of components that
optimize the efficiency and sensitivity of the Wi-Fi communications.
An RF feed line runs from the PØ module into a SPDT RF-switch. Logic level control lines on the PØ
module select which of the two ports of the RF-switch is connected to the RF feed line. A 100pF
decoupling capacitor is located on each control line. One port is connected to a PCB ceramic chip
antenna, and the other is connected to a u.FL connector for external antenna adaptation. The default
port will be set to the chip antenna.
Additionally, a user API is available to switch between internal, external and even an automatic
mode which continuously switches between each antenna and selects the best signal. All three RF
ports on the RF-switch have a 10pF RF quality DC-blocking capacitor in series with them. These
effectively pass 2.4GHz frequencies freely while blocking unwanted DC voltages from damaging the
RF-switch. All RF traces are considered as tiny transmission lines that have a controlled 50 ohm
impedance.
The chip antenna is impedance matched to the 50 ohm RF feed line via a Pi network comprised of
three RF inductors (1 series, 2 shunt). These values are quite specific to the Photon due to the PCB
construction and layout of the RF section. Even if the Photon's layout design is copied exactly, to
achieve the best performance it would be worth re-examining the Pi network values on actual
samples of the PCB in question.
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FCC APPROVED ANTENNAS
PERIPHERALS AND GPIO
The Photon has ton of capability in a small footprint, with analog, digital and communication
interfaces.
Notes:
[1] FT = 5.0V tolerant pins. All pins except A3 and DAC are 5V tolerant (when not in analog mode). If
used as a 5V input the pull-up/pull-down resistor must be disabled.
[2] 3V3 = 3.3V max pins.
[3] PWM is available on D0, D1, D2, D3, A4, A5, WKP, RX, TX with a caveat: PWM timer peripheral is
duplicated on two pins (A5/D2) and (A4/D3) for 7 total independent PWM outputs. For example:
PWM may be used on A5 while D2 is used as a GPIO, or D2 as a PWM while A5 is used as an
analog input. However A5 and D2 cannot be used as independently controlled PWM outputs at the
same time.
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JTAG AND SWD
Pin D3 through D7 are JTAG interface pins. These can be used to reprogram your Photon
bootloader or user firmware image with standard JTAG tools such as the ST-Link v2, J-Link, R-Link,
OLIMEX ARM-USB-TINI-H, and also the FTDI-based Particle JTAG Programmer. If you are short on
available pins, you may also use SWD mode which requires less connections.
Notes: [1] Default state after reset for a short period of time before these pins are restored to GPIO (if
JTAG debugging is not required, i.e. USE_SWD_JTAG=y is not specified on the command line.)
A standard 20-pin 0.1" shrouded male JTAG interface connector should be wired as follows:
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EXTERNAL COEXISTENCE INTERFACE
The Photon supports coexistence with Bluetooth and other external radios via the three gold pads on
the top side of the PCB near pin A3. These pads are 0.035" square, spaced 0.049" apart. This
spacing supports the possibility of tacking on a small 1.25mm - 1.27mm pitch 3-pin male header to
make it somewhat easier to interface with.
When two radios occupying the same frequency band are used in the same system, such as Wi-Fi
and Bluetooth, a coexistence interface can be used to coordinate transmit activity, to ensure optimal
performance by arbitrating conflicts between the two radios.
When these pads are programmed to be used as a Bluetooth coexistence interface, they're set as
high impedance on power up and reset.
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Memory Map
STM32F205RGY6 FLASH LAYOUT OVERVIEW
Bootloader (16 KB)
DCT1 (16 KB), stores Wi-Fi credentials, keys, mfg info, system flags, etc..
DCT2 (16 KB), swap area for DCT1
EEPROM emulation bank 1 (16 KB)
EEPROM emulation bank 2 (64 KB) [only 16k used]
System firmware (512 KB) [256 KB Wi-Fi/comms + 256 KB hal/platform/services]
Factory backup, OTA backup and user application (384 KB) [3 x 128 KB]
DCT LAYOUT
The DCT area of flash memory has been mapped to a separate DFU media device so that we can
incrementally update the application data. This allows one item (say, server public key) to be
updated without erasing the other items.
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Note: Writing 0xFF to offset 34 (DEFAULT) or 3106 (ALTERNATE) will cause the device to re-
generate a new private key on the next boot. Alternate keys are currently unsupported on the Photon
but are used on the Electron as UDP/ECC keys. You should not need to use this feature unless your
keys are corrupted.
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MEMORY MAP (COMMON)
MEMORY MAP (MODULAR FIRMWARE - DEFAULT)
MEMORY MAP (MONOLITHIC FIRMWARE - OPTIONAL)
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Pin and button definition
PIN MARKINGS
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PIN DESCRIPTION
In addition to the 24 pins around the outside of the Photon, there are 7 pads on the bottom the
Photon PCB that can be used to connect to extra signals: RGB LED outputs, SETUP button, SMPS
enable line and USB D+/D-. Photon Pins #25-31 are described in the Pin out diagrams. Also refer to
the Recommended PCB land pattern photon without headers section for their location on the bottom
of the Photon.
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PIN OUT DIAGRAMS
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Technical specification
ABSOLUTE MAXIMUM RATINGS
RECOMMENDED OPERATING CONDITIONS
[1] These numbers represent the extreme range of short peak current bursts when transmitting and receiving in
802.11b/g/n modes at different power levels. Average TX current consumption in will be 80-100mA.
[2] These are very short average current bursts when transmitting and receiving. On average if minimizing
frequency of TX/RX events, current consumption in powersave mode will be 18mA
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WI-FI SPECIFICATIONS
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I/O CHARACTERISTICS
These specifications are based on the STM32F205RGY6 datasheet, with reference to Photon pin
nomenclature.
Notes:
[1] FT = Five-volt tolerant. In order to sustain a voltage higher than V3V3+0.3 the internal pull-up/pull-
down resistors must be disabled.
[2] Hysteresis voltage between Schmitt trigger switching levels. Based on characterization, not tested
in production.
[3] With a minimum of 100mV.
[4] Leakage could be higher than max. if negative current is injected on adjacent pins.
[5] Pull-up and pull-down resistors are designed with a true resistance in series with switchable
PMOS/NMOS. This PMOS/NMOS contribution to the series resistance is minimum (~10% order).
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Mechanical specifications
DIMENSIONS AND WEIGHT
MATING CONNECTORS
The Photon (with headers) can be mounted with (qty 2) 12-pin single row 0.1" female headers.
Typically these are 0.335" (8.5mm) tall, but you may pick a taller one if desired. When you search for
parts like these it can be difficult to navigate the thousands of parts available online so here are a
few good choices for the Photon:
You may also use other types, such as reverse mounted (bottom side SMT) female headers, low
profile types, etc..
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RECOMMENDED PCB LAND PATTERN (PHOTON WITHOUT HEADERS)
The Photon (without headers) can be surface mounted directly in an end application PCB using the
following PCB land pattern:
In addition to the 24 pins around the outside of the Photon, there are 7 pads on the bottom the
Photon PCB that can be used to connect to extra signals: RGB LED outputs, SETUP button, SMPS
enable line and USB D+/D-. Photon Pins #25-31 are described in the Pin out diagrams.
Solder mask around exposed copper pads should be 0.1mm (4 mils) larger in all directions. E.g., a
0.08" x 0.10" pad would have a 0.088" x 0.108" solder mask.
A Photon without headers part for EAGLE can be found in the Particle EAGLE library
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Schematic
SCHEMATIC - USB
SCHEMATIC - POWER
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SCHEMATIC - USER I/O
SCHEMATIC - RF
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SCHEMATIC - PØ WI-FI MODULE
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PHOTON V1.0.0 TOP LAYER (GTL)
PHOTON V1.0.0 GND LAYER (G2L)
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PHOTON V1.0.0 3V3 LAYER (G15L)
PHOTON V1.0.0 BOTTOM LAYER (GBL)
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Recommended solder reflow profile
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Bill of Materials
BUILD YOUR OWN DESIGN BASED ON THE PHOTON!
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Qualification and approvals
Photon with Headers
Model Number: PHOTONH
RoHS
CE
FCC ID: 2AEMI-PHOTON
IC: 20127-PHOTON
Photon without Headers
Model Number: PHOTONNOH
RoHS
CE
FCC ID: 2AEMI-PHOTON
IC: 20127-PHOTON
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Product handling
PACKAGING
The Photon comes in two primary styles of packaging: Matchbox and Kit Box. The matchbox
packaging contains the bare essentials to get you started, while the Photon Kit contains a
breadboard, Micro B USB cable, sticker, prototyping card and a couple sensors to build your first
Internet connected project!
Photons without headers in matchbox packaging are also available in JEDEC style trays for
automated pick and place machines. Request more details from us on this in the Contact section
below.
MOISTURE SENSITIVITY LEVELS
The Moisture Sensitivity Level (MSL) relates to the packaging and handling precautions required.
The PØ module on the Photons dominate the MSL requirements and are rated level 3. In general,
this precaution applies for Photons without headers. If reflowing a Photon directly onto an application
PCB, increased moisture levels prior to reflow can damage sensitive electronics on the Photon. A
bake process to reduce moisture may be required.
For more information regarding moisture sensitivity levels, labeling, storage and drying see the MSL
standard see IPC/JEDEC J-STD-020 (can be downloaded from www.jedec.org).
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ESD PRECAUTIONS
The photon contains highly sensitive electronic circuitry and is an Electrostatic Sensitive Device
(ESD). Handling a photon without proper ESD protection may destroy or damage it permanently.
Proper ESD handling and packaging procedures must be applied throughout the processing,
handling and operation of any application that incorporates photons. ESD precautions should be
implemented on the application board where the photon is mounted. Failure to observe these
precautions can result in severe damage to the photon!
Default settings
The Photon comes preprogrammed with a bootloader and a user application called Tinker. This
application works with an iOS and Android app also named Tinker that allows you to very easily
toggle digital pins, take analog and digital readings and drive variable PWM outputs.
The bootloader allows you to easily update the user application via several different methods, USB,
OTA, Serial Y-Modem, and also internally via the Factory Reset procedure. All of these methods
have multiple tools associated with them as well.
You may use the online Web IDE Particle Build to code, compile and flash a user application OTA
(Over The Air). Particle Dev is a local tool that uses the Cloud to compile and flash OTA as well.
There is also a package Spark DFU-UTIL for Particle Dev that allows for Cloud compiling and local
flashing via DFU over USB. This requires dfu-util to be installed on your system. 'dfu-util' can also
be used with Particle CLI for Cloud compiling and local flashing via the command line. Finally the
lowest level of development is available via the GNU GCC toolchain for ARM, which offers local
compile and flash via dfu-util. This gives the user complete control of all source code and flashing
methods. This is an extensive list, however not exhaustive.
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Glossary
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FCC IC CE Warnings and End Product Labeling Requirements
Federal Communication Commission Interference Statement This equipment has been tested and
found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules.
These limits are designed to provide reasonable protection against harmful interference in a
residential installation. This equipment generates, uses and can radiate radio frequency energy and,
if not installed and used in accordance with the instructions, may cause harmful interference to radio
communications. However, there is no guarantee that interference will not occur in a particular
installation. If this equipment does cause harmful interference to radio or television reception, which
can be determined by turning the equipment off and on, the user is encouraged to try to correct the
interference by one of the following measures:
Reorient or relocate the receiving antenna.
Increase the separation between the equipment and receiver.
Connect the equipment into an outlet on a circuit different from that to which the receiver is
connected.
Consult the dealer or an experienced radio/TV technician for help.
FCC Caution: Any changes or modifications not expressly approved by the party responsible for
compliance could void the user's authority to operate this equipment. This device complies with Part
15 of the FCC Rules. Operation is subject to the following two conditions:
1. This device may not cause harmful interference, and
2. This device must accept any interference received, including interference that may cause
undesired operation.
FCC Radiation Exposure Statement: This equipment complies with FCC radiation exposure limits set
forth for an uncontrolled environment. This transmitter module must not be co-located or operating in
conjunction with any other antenna or transmitter. This End equipment should be installed and
operated with a minimum distance of 20 centimeters between the radiator and your body.
IMPORTANT NOTE: In the event that these conditions can not be met (for example certain laptop
configurations or co-location with another transmitter), then the FCC authorization is no longer
considered valid and the FCC ID can not be used on the final product. In these circumstances, the
OEM integrator will be responsible for re-evaluating the end product (including the transmitter) and
obtaining a separate FCC authorization.
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End Product Labeling The final end product must be labeled in a visible area with the following:
Contains FCC ID: 2AEMI-PHOTON
Manual Information to the End User The OEM integrator has to be aware not to provide information
to the end user regarding how to install or remove this RF module in the user’s manual of the end
product which integrates this module.
Canada Statement This device complies with Industry Canada’s licence-exempt RSSs. Operation is
subject to the following two conditions:
1. This device may not cause interference; and
2. This device must accept any interference, including interference that may cause undesired
operation of the device.
Le présent appareil est conforme aux CNR d’Industrie Canada applicables aux appareils radio
exempts de licence.
L’exploitation est autorisée aux deux conditions suivantes:
1. l’appareil ne doit pas produire de brouillage;
2. l’utilisateur de l’appareil doit accepter tout brouillage radioélectrique subi, même si le
brouillage est susceptible d’en compromettre le fonctionnement.
Caution Exposure: This device meets the exemption from the routine evaluation limits in section 2.5
of RSS102 and users can obtain Canadian information on RF exposure and compliance. Le
dispositif répond à l'exemption des limites d'évaluation de routine dans la section 2.5 de RSS102 et
les utilisateurs peuvent obtenir des renseignements canadiens sur l'exposition aux RF et le respect.
The final end product must be labelled in a visible area with the following: The Industry Canada
certification label of a module shall be clearly visible at all times when installed in the host device,
otherwise the host device must be labelled to display the Industry Canada certification number of the
module, preceded by the words “Contains transmitter module”, or the word “Contains”, or similar
wording expressing the same meaning, as follows:
Contains transmitter module IC: 20127-PHOTON
This End equipment should be installed and operated with a minimum distance of 20 centimeters
between the radiator and your body. Cet équipement devrait être installé et actionné avec une
distance minimum de 20 centimètres entre le radiateur et votre corps.
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The end user manual shall include all required regulatory information/warning as shown in this
manual.
Revision history
Contact
Web
https://www.particle.io
Community Forums
https://community.particle.io
Email
hello@particle.io
