The Electron is a tiny development kit for creating cellular-connected electronics projects and products. It comes with a SIM
card (Nano 4FF) and an affordable data plan for low-bandwidth things. Plus it's available for more than 100 countries
worldwide!
It also comes with Particle's development tools and cloud platform for managing and interacting with your new connected
hardware.
Electron Datasheet(v005)
Functional description
OVERVIEW
FEATURES
U-blox SARA-U260/U270 (3G) and G350 (2G) cellular module
STM32F205RGT6 120MHz ARM Cortex M3 microcontroller
1MB flash, 128KB RAM
BQ24195 power management unit and battery charger
MAX17043 fuel gauge
RGB status LED
30 mixed-signal GPIO and advanced peripherals
Open source design
Real-time operation system (RTOS)
FCC, CE and IC certified
Interfaces
BLOCK DIAGRAM
The Electron can be powered via the VIN (3.9V-12VDC) pin, the USB Micro B connector or a LiPo battery.
Most USB ports can supply only a maximum of 500mA, but the u-Blox GSM module on the Electron alone can consume a
peak of 800mA to 1800mA of current during transmission. In order to compensate of this deficit, one must connect the LiPo
battery at all times when powering from a traditional USB port. The Electron will intelligently source power from the USB most
of the time and keep the battery charged. During peak current requirements, the additional power will be sourced from the
battery. This reduces the charge-discharge cycle load on the battery, thus improving its longevity.
The input voltage range on VIN pin is 3.9VDC to 12VDC. When powering from the VIN pin alone, make sure that the power
supply is rated at 10W (for example 5VDC at 2Amp). If the power source is unable to meet this requirement, you'll need
connect the LiPo battery as well. An additional bulk capacitance of 470uF to 1000uF should be added to the VIN input when
the LiPo Battery is disconnected. The amount of capacitance required will depend on the ability of the power supply to
deliver peak currents to the cellular modem.
When powered from a LiPo battery alone, the power management IC switches off the internal regulator and supplies power
to the system directly from the battery. This reduces the conduction losses and maximizes battery run time. The battery
provided with the Electron is a Lithium-Ion Polymer battery rated at 3.7VDC 2000mAh. You can substitute this battery with
another 3.7V LiPo with higher current rating. Remember to never exceed this voltage rating and always pay attention to the
polarity of the connector.
Typical current consumption is around 180mA and up to 1.8A transients at 5VDC. In deep sleep mode, the quiescent current
is 130uA (powered from the battery alone).
This pin is internally tied to the positive terminal of the LiPo battery connector. It is intentionally left unpopulated. Please note
that an incorrect usage of this pin can render the Electron unusable.
Li+ pin serves two purposes. You can use this pin to connect a LiPo battery directly without having to use a JST connector or
it can be used to connect an external DC power source (and this is where one needs to take extra precautions). When
powering it from an external regulated DC source, the recommended input voltage range on this pin is between 3.6V to
4.4VDC. Make sure that the supply can handle currents of at least 2 Amps.
POWER
USB
VIN
LIPO BATTERY
LI+
This is the most efficient way of powering the Electron since the PMIC by-passes the regulator and supplies power to the
Electron via an internal FET leading to lower quiescent current.
This pin is internally connected to USB supply rail and will output 5V when the Electron is plugged into an USB port. It is
intentionally left unpopulated. This pin willNOToutput any voltage when the Electron is powered via VIN and/or the LiPo
battery.
This pin is the output of the on-board 3.3V switching regulator that powers the microcontroller and the peripherals. This pin
can be used as a 3.3V power source with a max load of 800mA. Unlike the Photon or the Core, this pinCANNOTbe used
as an input to power the Electron.
Supply to the internal RTC, backup registers and SRAM when 3V3 is not present (1.65 to 3.6VDC). The Pin is internally
connected to 3V3 supply via a 0 ohm resistor. If you wish to power VBAT via an external supply, you'll need to remove this
resistor with a desoldering iron. Contact us if you wish to request trays of electrons with this jumper depopulated.
The most forgiving way to power the Electron without a battery is via the VIN inputsee VIN above. Power may also be applied
separately to the Li+ pin or LiPo JST connectorsee Li+ above.
Antenna Type Manufacturer MFG. Part # Gain
PCB antenna Taoglas PC104.07.0165C 1dBi ~ 2.39dBi
Peripheral Type Qty Input(I) / Output(O) FT / 3V3
Digital 30 I/O FT/3V3
Analog (ADC) 12 I 3V3
VUSB
3V3 PIN
VBAT
POWERING THE ELECTRON WITHOUT A BATTERY
FCC APPROVED ANTENNAS
PERIPHERALS AND GPIO
[1] [2]
Peripheral Type Qty Input(I) / Output(O) FT / 3V3
Analog (ADC)
Analog (DAC) 2 O 3V3
UART 3 I/O 3V3
SPI 2 I/O 3V3
I2S 1 I/O 3V3
I2C 1 I/O FT
CAN 2 I/O 3V3
USB 1 I/O 3V3
PWM 13 O 3V3
Notes: 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.
3V3 = 3.3V max pins.
PWM is available on D0, D1, D2, D3, B0, B1, B2, B3, A4, A5, WKP, RX, TX with a caveat: PWM timer peripheral is
duplicated on two pins (A5/D2) and (A4/D3) for 11 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.
Technically these pins are 5.0V tolerant, but since you wouldn't operate them with a 5.0V transceiver it's proper to classify
them as 3.3V.
Pin D3 through D7 are JTAG interface pins. These can be used to reprogram your Electron 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.
Electron Pin JTAG SWD STM32F205RGT6 Pin Default Internal
D7 JTAG_TMS SWD/SWDIO PA13 ~40k pull-up
D6 JTAG_TCK CLK/SWCLK PA14 ~40k pull-down
D5 JTAG_TDI PA15 ~40k pull-up
D4 JTAG_TDO PB3 Floating
D3 JTAG_TRST PB4 ~40k pull-up
3V3 Power
GND Ground
[4]
3
[1]
[2]
[3]
[4]
JTAG AND SWD
[1]
RST Reset
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.)
Bootloader (16 KB)
DCD1 (16 KB), stores keys, mfg info, system flags, etc..
DCD2 (16 KB), swap area for DCD1
EEPROM emulation bank 1 (16 KB)
EEPROM emulation bank 2 (64 KB)
System firmware (512 KB) [256 KB comms + 256 KB hal/platform/services]
Factory backup, OTA backup and user application (384 KB) [3 x 128 KB]
The DCD 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.
DCD layout in
release/stable
found here in firmware.
Region Offset Size
system flags 0 32
version 32 2
device private key 34 1216
device public key 1250 384
ip config 1634 120
feature flags 1754 4
country code 1758 4
claim code 1762 63
claimed 1825 1
ssid prefix 1826 26
device code 1852 6
version string 1858 32
Memory Map
STM32F205RGT6 FLASH LAYOUT OVERVIEW
DCD LAYOUT
Region Offset Size
version string 1858 32
dns resolve 1890 128
reserved1 2018 64
server public key 2082 768
padding 2850 2
flash modules 2852 100
product store 2952 24
antenna selection 2976 1
cloud transport 2977 1
alt device public key 2978 128
alt device private key 3106 192
alt server public key 3298 192
alt server address 3490 128
device id 3618 12
radio flags 3630 1
mode button mirror 3631 32
led mirror 3663 96
led theme 3759 64
reserved2 3823 435
Note:Writing 0xFF to offset 3106 (DEFAULT key used on Electron) will cause the device to re-generate a new private
UDP/ECC key on the next boot. TCP keys are currently unsupported on the Electron but would be located at offset 34. You
should not need to use this feature unless your keys are corrupted.
Region Start Address End Address Size
Bootloader 0x8000000 0x8004000 16 KB
DCD1 0x8004000 0x8008000 16 KB
DCD2 0x8008000 0x800C000 16 KB
MEMORY MAP (COMMON)
// Regenerate Alternate Keys (Default)
echo -e "\xFF" > fillbyte && dfu-util -d 2b04:d00a -a 1 -s 3106 -D fillbyte
// Regenerate TCP Keys (Unsupported)
echo -e "\xFF" > fillbyte && dfu-util -d 2b04:d00a -a 1 -s 34 -D fillbyte
EEPROM1 0x800C000 0x8010000 16 KB
EEPROM2 0x8010000 0x8020000 64 KB
Before 0.6.0 firmware
Region Start Address End Address Size
System Part 1 0x8020000 0x8040000 128 KB
System Part 2 0x8040000 0x8060000 128 KB
Application 0x8080000 0x80A0000 128 KB
Factory Reset/Extended Application 0x80A0000 0x80C0000 128 KB
OTA Backup 0x80C0000 0x80E0000 128 KB
Decompress region 0x80E0000 0x8100000 128 KB
Since 0.6.0 firmware
Region Start Address End Address Size
System Part 2 0x8020000 0x8040000 128 KB
System Part 3 0x8040000 0x8060000 128 KB
System Part 1 0x8060000 0x8080000 128 KB
Application 0x8080000 0x80A0000 128 KB
Factory Reset/Extended Application 0x80A0000 0x80C0000 128 KB
OTA Backup 0x80C0000 0x80E0000 128 KB
Decompress region 0x80E0000 0x8100000 128 KB
Region Start Address End Address Size
Firmware 0x8020000 0x8080000 384 KB
Factory Reset 0x8080000 0x80E0000 384 KB
Unused (factory reset modular) 0x80E0000 0x8100000 128 KB
MEMORY MAP (MODULAR FIRMWARE - DEFAULT)
MEMORY MAP (MONOLITHIC FIRMWARE - OPTIONAL)
Pin and button definition
PIN MARKINGS:
Pin Description
VIN This pin can be used as an input or output. As an input, supply 5VDC to 12VDC to power the Electron. When the Electron is powered via
the USB port, this pin will output a voltage of approximately 4.8VDC due to a reverse polarity protection series Schottky diode between
VUSB and VIN. When used as an output, the max load on VIN is 1Amp.
RST Active-low reset input. On-board circuitry contains a 10k ohm pull-up resistor between RST and 3V3, and 0.1uF capacitor between RST
and GND.
VBAT Supply to the internal RTC, backup registers and SRAM when 3V3 is not present (1.65 to 3.6VDC). The Pin is internally connected to 3V3
supply via a 0 ohm resistor. If you wish to power VBAT via an external supply, you'll need to remove this resistor with a desoldering iron.
Contact us if you wish to request trays of electrons with this jumper depopulated.
3V3 This pin is the output of the on-board regulator. When powering the Electron via VIN or the USB port, this pin will output a voltage of
3.3VDC. The max load on 3V3 is 800mA. It should not be used as an input to power the Electron.
WKP Active-high wakeup pin, wakes the module from sleep/standby modes. When not used as a WAKEUP, this pin can also be used as a
digital GPIO, ADC input or PWM . Can be referred to as A7 when used as an ADC.
DAC 12-bit Digital-to-Analog (D/A) output (0-4095), referred to as DAC or DAC1 in software. Can also be used as a digital GPIO or ADC.
Can be referred to as A6 when used as an ADC.
RX Primarily used as UART RX, but can also be used as a digital GPIO or PWM .
TX Primarily used as UART TX, but can also be used as a digital GPIO or PWM .
PIN DESCRIPTION
[1]
[1]
[1]
TX Primarily used as UART TX, but can also be used as a digital GPIO or PWM .
D0-
D7
Digital only GPIO. D0, D1, D2, D3 can also be used as PWM outputs.
A0-
A7
12-bit Analog-to-Digital (A/D) inputs (0-4095), and also digital GPIOs. A6 and A7 are code convenience mappings, which means pins are
not actually labeled as such but you may use code like analogRead(A7) . A6 maps to the DAC pin and A7 maps to
the WKP pin. A3 is also a second DAC output used as DAC2 or A3 in software. A4 and A5 can also be used as PWM outputs.
B0-
B5
B0 and B1 are digital only while B2, B3, B4, B5 are 12-bit A/D inputs as well as digital GPIOs. B0, B1, B2, B3 can
also be used as PWM outputs.
C0-
C5
Digital only GPIO. C4 and C5 can also be used as PWM outputs.
VUSB This pin is internally connected to USB supply and will output 5V when the Electron is plugged into an USB port. It is intentionally left
unpopulated.
Li+ This pin is internally connected to the positive terminal of the LiPo battery. It is intentionally left unpopulated.
Notes:
PWM is available on D0, D1, D2, D3, B0, B1, B2, B3, A4, A5, WKP, RX, TX with a caveat: PWM timer peripheral is
duplicated on two pins (A5/D2) and (A4/D3) for 11 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.
State Description
ON Charging in progress
OFF Charging complete
Blink at 1Hz Fault condition
Rapid blinking Battery disconnected
Notes:
A fault condition can occur due to several reasons, for example, battery over/under voltage, temperature fault or safety
timer fault. You can find the root cause by reading the fault register of the power management IC in firmware.
You can stop this behavior by either plugging in the LiPo battery or by disabling charging using firmware
command: PMIC().disableCharging(); .
[1]
[1]
[1]
[1]
[1]
[1]
LED STATUS
CHARGE STATUS LED
[1]
[2]
[1]
[2]
For a detailed explanation of different color codes of the RGB system LED, please take a lookhere.
You can download a high resolution pinout diagram in aPDF version here.
Parameter Symbol Min Typ Max Unit
Supply Input Voltage V +17 V
SYSTEM RGB LED
PINOUT DIAGRAM
Technical Specifications
ABSOLUTE MAXIMUM RATINGS[1]
IN-MAX
Parameter Symbol Min Typ Max Unit
Supply Input Voltage V +17 V
Supply Output Current I 1 A
Battery Input Voltage V +6 V
Supply Output Current I 800 mA
Storage Temperature T -30 +75 °C
ESD Susceptibility HBM (Human Body Mode) V 2 kV
Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are
stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under
recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods
may affect device reliability.
Parameter Symbol Min Typ Max Unit
Parameter Symbol Min Typ Max Unit
Supply Input Voltage V +3.88 +12 V
Supply Output Voltage V +4.8 V
Supply Output Voltage V +3.3 V
LiPo Battery Voltage V +3.6 +4.4 V
Supply Input Voltage V +1.65 +3.6 V
Supply Input Current (VBAT) I 19 uA
Operating Current (uC on, Cellular ON) I 180 250 mA
Peak Current (uC on, Cellular ON) I 800 1800 mA
Operating Current (uC on, Cellular OFF) I 47 50 mA
Sleep Current (4.2V LiPo, Cellular OFF) I 0.8 2 mA
Deep Sleep Current (4.2V LiPo, Cellular OFF) I 110 130 uA
Operating Temperature T -20 +60 °C
Humidity Range Non condensing, relative humidity 95 %
Notes:
IN-MAX
IN-MAX-L
LiPo
3V3-MAX-L
stg
ESD
[1]
RECOMMENDED OPERATING CONDITIONS
VIN [1]
VIN
3V3
LiPo
VBAT
VBAT
VIN avg
VIN pk [2] [3]
VIN avg
Qs
Qds
op
The minimum input voltage is software defined with a user selectable range of 3.88V to 5.08V in 80mV increments. Out of
the box, the minimum input voltage is set to 4.36V in order for the LiPo battery to be able to properly charge.
3G operation
2G operation
The Electron is available in three different versions: A 2G version based on u-blox G350 cellular module, and two 3G versions
based on U260 and U270 modules. The difference between the 3G versions is their operating frequency band which differs
based on the country. All of these cellular modules are GSM only and do not support CDMA networks.
Electron
3G
Module Compatible Countries
U260 United States, Australia, Argentina, Brazil, Canada, Chile, Colombia, Costa Rica, Dominican Republic, El Salvador, Guatemala,
Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, Venezuela
U270 Austria, Bahrain, Belarus, Belgium, Bulgaria, China, Congo, Croatia, Cyprus, Czech Republic, Denmark, Ecuador, Egypt, Estonia,
Finland, France, Germany, Ghana, Gibraltar, Greece, Hong Kong, Hungary, Iceland, India, Indonesia, Ireland, Israel, Italy, Japan, Jersey,
Kenya, Republic of Korea, Latvia, Lithuania, Luxembourg, Republic of Macedonia, Malaysia, Republic of Moldova, Republic of
Montenegro, Netherlands, New Zealand, Nigeria, Norway, Pakistan, Philippines, Poland, Portugal, Qatar, Reunion, Romania, Russian
Federation, Rwanda, Saudi Arabia, Republic of Serbia, Seychelles, Sierra Leone, Singapore, Slovakia, Slovenia, South Africa, Spain,
Sri Lanka, Swaziland, Sweden, Switzerland, Taiwan, United Republic of Tanzania, Thailand, Turkey, Uganda, Ukraine, United Arab
Emirates, United Kingdom, Uruguay, Zambia
Please be sure to order a board that works in the country where you want to deploy your project.
Parameter SARA-U260 SARA-U270 SARA-G350
Protocol
stack
3GPP Release 7 3GPP Release 7 3GPP Release 99
MS Class Class B Class B Class B
Bands GSM 850 MHz PCS 1900 MHz E-GSM 900 MHz DCS 1800 MHz GSM 850 MHz E-GSM 900 MHz DCS 1800
MHz PCS 1900 MHz
Power
Class
Class 4 (33 dBm) for 850 band Class 1
(30 dBm) for 1900 band
Class 4 (33 dBm) for 900 band Class 1
(30 dBm) for 1800 band
Class 4 (33 dBm) for 850/900 bands Class 1 (30
dBm) for 1800/1900 bands
[1]
[2]
[3]
RADIO SPECIFICATIONS
2G CELLULAR CHARACTERISTICS FOR G350, U260, AND U270 MODULES:
Parameter SARA-U260 SARA-U270
Protocol stack 3GPP Release 7 3GPP Release 7
UE Class Class A Class A
Bands Band V (850 MHz) Band II (1900 MHz) Band VIII (900 MHz) Band I (2100 MHz)
Power Class Class 3 (24 dBm) for all bands Class 3 (24 dBm) for all bands
These specifications are based on the STM32F205RGT6 datasheet, with reference to Electron pin nomenclature.
Parameter Symbol Conditions Min Typ Max Unit
Parameter Symbol Conditions Min Typ Max Unit
Standard I/O input low level voltage V -0.3 0.28*(V -2)+0.8 V
I/O FT input low level voltage V -0.3 0.32*(V -2)+0.75 V
Standard I/O input high level voltage V 0.41*(V -2)+1.3 V +0.3 V
I/O FT input high level voltage V V > 2V 0.42*(V -2)+1 5.5 V
V V ≤ 2V 0.42*(V -2)+1 5.2 V
Standard I/O Schmitt trigger voltage hysteresis V 200 mV
I/O FT Schmitt trigger voltage hysteresis V 5% V mV
Input leakage current I GND ≤ V ≤ V GPIOs ±1 µA
Input leakage current I R V = 5V, I/O FT 3 µA
Weak pull-up equivalent resistor R V = GND 30 40 50 k Ω
Weak pull-down equivalent resistor R V = V 30 40 50 k Ω
I/O pin capacitance C 5 pF
DAC output voltage (buffers enabled by default) V 0.2 V -0.2 V
DAC output resistive load (buffers enabled by default) R 5 k Ω
DAC output capacitive load (buffers enabled by default) C 50 pF
Notes:
3G CELLULAR CHARACTERISTICS FOR U260, AND U270 MODULES:
I/O CHARACTERISTICS
IL 3V3
[1] IL 3V3
IH 3V3 3V3
[1] IH 3V3 3V3
IH 3V3 3V3
[2] hys
[2] hys 3V3[3]
[4] lkg io 3V3
[4] lkg PU io
[5] PU io
[5] PD io 3V3
IO
DAC 3V3
DAC
DAC
FT = Five-volt tolerant. In order to sustain a voltage higher than V +0.3 the internal pull-up/pull-down resistors must be
disabled.
Hysteresis voltage between Schmitt trigger switching levels. Based on characterization, not tested in production.
With a minimum of 100mV.
Leakage could be higher than max. if negative current is injected on adjacent pins.
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).
Width = 0.8"
Height = 0.65"
Length = 2.05"
Weight = 10 grams
The Electron can be mounted with (qty 2) 18-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 Electron:
Description MFG MFG Part Number Distributor
18-pin 0.1" (2.54mm) Female Header (Tin) Sullins Connector Solutions PPTC181LFBN-RC DigiKey
18-pin 0.1" (2.54mm) Female Header (Tin) 3M 929974-01-18-RK DigiKey
18-pin 0.1" (2.54mm) Female Header (Tin) Harwin M20-7821846 Mouser
You may also use other types, such as reverse mounted (bottom side SMT) female headers, low profile types, etc..
The Electron can be mounted with 0.1" 18-pin female header receptacles using the following PCB land pattern:
[1] 3V3
[2]
[3]
[4]
[5]
Mechanical Specifications
DIMENSIONS AND WEIGHT
MATING CONNECTORS
RECOMMENDED PCB LAND PATTERN
An Electron part for EAGLE can be found in theParticle EAGLE library
All of the Electron hardware design files are open source and available under a Creative Commons Public License. The
schematic and PCB designs were made using EAGLE CAD. You can access these fileshere.
Note:Clone or Download the complete repository as a ZIP file to avoid corrupted data in Eagle files.
Schematic
USB
The USB data lines are terminated with 22 Ohm resistors. These data pins are also exposed via small through holes next to
the USB connector and are labeled D+ and D-. The VBUS (+5VDC VCC of the USB port) is fed to the PMIC via a 3Amp
Schottky diode (SS3P3). The VBUS pin is also available via the unpopulated header hole on the top-right side of the
Electron.
PMIC (POWER MANAGEMENT INTEGRATED CIRCUIT)
The Electron uses TI'sBQ24195as the power management and charging unit. This PMIC intelligently sources power from
either the VIN pin, the USB port and/or the LiPo battery. When all the power sources as connected, the unit tries to source
power from the USB or VIN as default and continues to charge the LiPo battery. When the battery is completely charged, the
power is then sourced from USB/VIN alone. If there is a power deficit (which generally occurs during cellular radio
transmission), the additional power is then sourced from the battery as required. The unit can also seamlessly switch back to
the battery when other sources of power are suddenly removed.
The DP data pin of the USB is used by the PMIC to detect the presence of a USB power source. It then adjusts the charge
current and the limit based on the type of USB power source it detects. This does not always happen successfully since
there are a lot of USB hubs and chargers out there that do not meet the USB design guidelines. If the detection is
unsuccessful, the PMIC defaults to a 500mA current limit. A user can always adjust these parameters via software.
The microcontroller communicates with the PMIC via an I2C interface (pins PC9 and PA8). This interface allows the
microcontroller to read the status of the PMIC and set its various parameters.
MICROCONTROLLER
The Electron uses ST Microelectronics'sSTM32F205RGT6ARM Cortex M3 microcontroller running at 120MHz.
U-BLOX CELLULAR MODULE
The u-blox cellular module talks to the microcontroller over a full-duplex USART interface using a standard set of AT
commands. The SIM (Nano 4FF) card is directly connected to the u-blox. The power to the SIM card is also provided by the
cellular module.
BUFFERS
Since u-blox module's communication interface operates at 1.8VDC, while the STM32F205RGT6 microcontroller operates at
3.3VDC, we need voltage translators in-between them. This is achieved with twoSN74AVC4T245non-inverting buffers. The
default state of the USART pins is set with the help of pull-up and pull-down resistors, and the unused input pins are tied to
GND.
3.3V REGULATOR AND FUEL GAUGE
The output (3.8V net) of the PMIC is fed directly to the u-blox cellular module and a 3.3VDC high efficiency switching
regulator (TPS62290). This 3.3VDC regulator helps power the microcontroller, fuel gauge and the buffers.
The Electron employs aMAX17043fuel gauge to monitor the LiPo battery voltage and it's state of charge. The
microcontroller communicates with it over an I2C interface (same channel as the PMIC).
The Electron uses a four layer circuit board. Top layer consists of a signal layer followed by ground (GND), 3.3V power (3V3),
and bottom signal.
Layout
QTY Device Value Package Designator Manufacturer MFG. Part #
14 CAPACITOR 0.1uF, 6.3V,
10%
0402 C14, C17, C18, C19, C2, C20, C21,
C22, C29, C30, C31, C6, C8, C9
Fenghua 0402B104K160NT
2 CAPACITOR 10nF, 6.3V,
10%
0402 C1,C38 Fenghua 0402B103K500NT
5 CAPACITOR 10uF, 6.3V,
10%
0603 C23, C24, C27, C40, C41 Yageo CC0603KRX5R5BB106
2 CAPACITOR 12pF, 6.3V,
10%
0402 C33, C34 Fenghua 0402CG120J500NT
1 CAPACITOR 15pF, 6.3V,
10%
0402 C16 Fenghua 0402CG150J500NT
2 CAPACITOR 1uF, 6.3V,
10%
0402 C37, C39 Fenghua 0402X105K6R3NT
1 CAPACITOR 1uF, 25V,
10%
0603 C4 Yageo CC0603KRX5R8BB105
2 CAPACITOR 2.2uF, 6.3V,
10%
0402 C32, C35 Yageo CC0402KRX5R5BB225
2 CAPACITOR 20pF, 6.3V, 0402 C26, C28 Fenghua 0402CG200J500NT
Bill of Materials
QTY Device Value Package Designator Manufacturer MFG. Part #
2 CAPACITOR 20pF, 6.3V,
10%
0402 C26, C28 Fenghua 0402CG200J500NT
1 CAPACITOR 22uF, 6.3V,
10%
0603 C5 Samsung CL10A226KQ8NRNE
1 CAPACITOR 220uF, 6.3V,
10%
2312 (6032
metric)
C3 AVX TAJC227K006
1 CAPACITOR 4.7uF, 6.3V,
10%
0402 C36 Samsung CL05A475KQ5NRNC
1 CAPACITOR 4.7uF, 6.3V,
10%
0603 C25 Yageo CC0603KRX5R5BB475
1 CAPACITOR 47nF, 6.3V,
10%
0402 C7 Fenghua 0402B473K160NT
4 CAPACITOR 47pF, 6.3V,
10%
0402 C10, C11, C12, C13 Fenghua 0402CG470J500NT
1 CAPACITOR 68pF, 6.3V,
10%
0402 C15 Fenghua 0402CG680J500NT
1 CONNECTOR 2-pin SMD, 2-pin,
Vertical
JP4 Kaweei CW2001-02T-M01-D
1 CONNECTOR 1x18 1x18, 0.1"
pitch"
JP1 Kaweei CP25411-18G-S116A-A
1 CONNECTOR 1x18 1x18, 0.1"
pitch"
JP2 Kaweei CP25411-18G-S116B-A
1 CONNECTOR USB-MICROB-
SLOT-HOLE
X1 Kaweei CMCUSB-5BFM2G-01-D
1 CONNECTOR SMD J2 Kaweei P1163-0140R
1 CONNECTOR 10mm x
12.3mm
J1 Kaweei CSIM2545-06S-D
1 CRYSTAL 26MHz,
<±20ppm
4-SMD, 5.0 x
3.2mm
Y2 Song Ji SJSMD5026M00018F20
1 CRYSTAL 32.768KHz,
<±20ppm
2-SMD, 1.5 x
3.2mm
Y1 Song Ji SJ FC1332K012F520P
1 DIODE 30V, 3A DO-220AA U$3 Vishay SS3P3-M3/84A
2 IC - Buffer SC-70-5 U5, U6 Texas
Instruments
SN74LVC1G07DCKR
1 IC - Fuel
Gauge
TDFN-8 U4 Maxim MAX17043G+T
1 IC - Cell
Module
16 x 26 x 3mm U1 u-blox SARA-G350SARA-
U260SARA-U270
2 IC - Buffer 16-UQFN U2, U8 Texas
Instruments
SN74AVC4T245RSVR
1 IC -
Microcontroller
LQFP64 U3 ST
Microelectronics
STM32F205RGT6
1 IC - PMIC 24VQFN U$1 Texas
Instruments
BQ24195RGER
1 IC - MOSFET SC70-5 U9 Texas
Instruments
TPS22942DCKR
QTY Device Value Package Designator Manufacturer MFG. Part #
1 IC - 3V3 Reg 1A 6-SON (2x2) U$5 Texas
Instruments
TPS62291DRVR
1 INDUCTOR 2.2uH, 1.5A,
20%
3.0 mm x 3.0
mm
U$6 Taiyo Yuden NR3015T2R2M
1 INDUCTOR 2.2uH, 4A 4.45mm x
4.06mm
U$4 Bourns, Inc. SRP4020TA-2R2M
1 LED Blue 0603 LED1 Everlight 19-217/BHC-
ZL1M2RY/3T
1 LED Red 0603 LED3 Everlight 19-217/R6C-
AL1M2VY/3T
1 LED RGB 4-PLCC (3.2
mm x 2.8mm)
LED2 Cree CLMVB-FKA-
CFHEHLCBB7A363
1 RESISTOR 0R, 1/16W 0201 R32 Fenghua
1 RESISTOR 100k, 1/16W,
5%
0402 R1 Fenghua RC-02W104JT
14 RESISTOR 10K, 1/16W,
5%
0402 R3, R8, R15, R16, R17, R19, R21, R24,
R25, R27, R28, R29, R30, R31
Fenghua RC-02W103JT
1 RESISTOR 150R,1/4W,
1%
0603 R22 Vishay CRCW0603150RFKEAHP
1 RESISTOR 1K, 1/16W,
5%
0603 R23 Fenghua RC-03K102JT
4 RESISTOR 1K, 1/16W,
5%
0402 R10, R11, R12, R9 Fenghua RC-02W102JT
1 RESISTOR 2.2K, 1/16W,
5%
0402 R4 Fenghua RC-02W222JT
2 RESISTOR 22R, 1/16W,
1%
0402 R5, R6 Fenghua RC-02W22R0FT
1 RESISTOR 330R,
1/16W, 1%
0402 R2 Fenghua RC-02W3300FT
2 RESISTOR 4K7, 1/16W,
5%
0402 R13, R14 Fenghua RC-02W472JT
1 RESISTOR 5.49K,
1/16W, 1%
0402 R18 Fenghua RC-02W5491FT
2 SWITCH 160gF 3.6mm x
3.1mm
MODE, RESET Haoyu TS-1185A-C
Electrons are available fromstore.particle.ioin single quantities in 2G, and 3G versions.
Ordering information
The Electron contains highly sensitive electronic circuitry and is an Electrostatic Sensitive Device (ESD). Handling a Electron
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 Electrons. ESD
precautions should be implemented on the application board where the Electron is mounted. Failure to observe these
precautions can result in severe damage to the Electron!
There are three connectors on the Electron that will get damaged with improper usage. The JST connector on the circuit
board, where you plug in the LiPo battery, is very durable but the connector on the battery itself is not. When unplugging the
battery, take extra precaution toNOTpull the connector using the wires, but instead hold the plug at its base to avoid putting
stress on the wires. This can be tricky with bare hands - nose pliers are your friend here.
Product Handling
ESD PRECAUTIONS
CONNECTORS
The micro B USB connector on the electron is soldered on the PCB with large surface pads as well as couple of through
hole anchor points. Despite this reinforcement, it is very easy to rip out the connector if too much stress is put on in the
vertical direction.
The u.FL antenna connector is a very fragile piece of hardware ( and is fancy too with all the gold plating). The connector was
not designed to be constantly plugged and unplugged. Care must be taken not to put stress on it at any time (yes, swinging
the Electron by the antenna is a very bad idea, this is not your cat). The antenna pin is also the most static sensitive and you
can destroy the radio with improper handling. If you are feeling adventurous, we highly recommend putting a tiny dab of glue
(epoxy, rubber cement, liquid tape or hot glue) on the connector to securely hold the plug in place.
The breadboard provided with the Electron is specifically designed to require low insertion force. This makes it easy to plug
the Electron in and out of the breadboard. If you end up using a different breadboard, remember that it may require more
force. In this case, always remember to pinch-hold your precious Electron by the sides (along the header pins) when
plugging-unplugging andnotby the USB connector (don't be this person).
The Electron comes pre-programmed 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.
BREADBOARDING
Default settings
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 tool chain 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.
Term Definition
SMPS Switch Mode Power Supply
SIM Subscriber Identity Module (Size: Nano 4FF)
RF Radio Frequency
SMT Surface Mount Technology (often associated with SMD which is a surface mount device).
LED Light Emitting Diode
RGB LED Red green and blue LEDs combined and diffused in one package.
USB Universal Serial Bus
Quiescent current Current consumed in the deepest sleep state.
FT Five-tolerant; Refers to a pin being tolerant to 5V.
3V3 +3.3Volt; The regulated +3.3V supply rail. Also used to note a pin is only 3.3V tolerant.
PMIC Power Management Integrated Circuit
LiPo Lithium-ion Polymer Battery
GSM Global System for Mobile Communications
CDMA Code Division Multiple Access
OTA Over The Air; describing how firmware is transferred to the device.
uC Microcontroller
Federal Communication Commission Interference StatementThis 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
Glossary
FCC IC CE Warnings and End Product Labeling Requirements
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.
End Product LabelingThe final end product must be labeled in a visible area with the following:
Contains FCC ID:
XPYSARAG350 (For 2G Electron using the G350 module)
XPYSARAU260 (For 3G Electron using the U260 module)
XPYSARAU270 (For 3G Electron using the U270 module)
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:
8595A-SARAG350 (For 2G Electron using the G350 module)
8595A-SARAU260 (For 3G Electron using the U260 module)
8595A-SARAU270 (For 3G Electron using the U270 module)
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.
The end user manual shall include all required regulatory information/warning as shown in this manual.
For an in-depth review on certifications, please clickhere.
Revision Date Author Comments
v001 20-
Jan-
2016
MB Initial release
v002 24-
March-
2016
MB Added: Memory map, DAC limits, SIM card size, SWD pin locations. Updated: Power section, pin diagram, block
diagram, operating conditions.
v003 12- BW Error in Cellular off operating current, changed from 2-15mA to 47-50mA. Also qualified these current readings with
Revision history
v003 12-
Sept-
2016
BW Error in Cellular off operating current, changed from 2-15mA to 47-50mA. Also qualified these current readings with
uC on/off. Updated the Pin Description section. Updated Mating connectors section.
v004 27-
Oct-
2016
BW Replaced one STM32F205RGY6 with STM32F205RGT6, and replaced all STM32 mentions with full part number
STM32F205RGT6
v005 14-
Aug-
2017
BW Updated DCD layout and Memory Map, renamed SPI1*/SPI3* to match Particle API instead of STM32 pin names to
avoid confusion (now SPI, SPI1 and SPI2), updated the Pin Description section and added high resolution pinout
PDF, updated LED Status section, VBAT info, added Power the Electron without a battery section
We are trackingknown errata with this datasheet here. These issues/errors in the datasheet will be resolved in subsequent
revisions.
Web
https://www.particle.io
Community Forums
https://community.particle.io
Email
https://support.particle.io
Known Errata
Contact