Page 31 - Programming the Photon Getting Started With the Internet of Things

Solid white Factory reset has completed and the Photon is resetting.

Flashing magenta The Photon is updating the firmware.
Solid magenta The Photon may have lost connection to the Particle cloud; by

pressing RESET the Photon board will attempt to update the firmware once more.

Although these LED statuses give us a good, clear indication as to what the Photon board
is doing, it is also useful when things don’t go so well. The RGB also flashes errors with a
red LED flash. These errors may include the following:

Two red flashes Connection failure due to a bad Internet connection.

Three red flashes There is an Internet connection but the Particle cloud is
inaccessible. Visit the Particle website for an up-to-date status of the cloud.

Flashing yellow/red The Wi-Fi credentials provided to the Photon board are
incorrect and as such cannot connect to the local Wi-Fi.

The Photon has 24 header pins that are clearly visible from underneath; each pin is also
clearly labeled on the silk screen (top). These pins are clearly labeled with the following:

VIN Indicated as voltage input; connect an unregulated power source to this pin
with a voltage between 3.6 V and 6 V (max) to power the Photon.

NOTE When powering the Photon through the USB port, the VIN pin should not be used.

3V3 This pin, as the name suggests, gives a regulated output voltage of 3.3 V that
can be used to power your circuits. This pin can also be used to power the Photon if

you have a regulated 3.3-V power source.

NOTE Powering the Photon using the 3.3-V rails is not recommended. Any overvoltage
may cause permanent damage to the board.

VBAT Supply to the internal Real Time Clock (RTC), back registers, and Static
Random Access Memory (SRAM) when the 3V3 is not present (1.65 to 3.6 V).

RST This pin allows you to reset your Photon when you connect it to one of the
ground pins on the Photon board.

GND The GND, or ground, pins are used to connect any positive voltage to ground.

D0 to D7 These pins represent a digital input/output value from an electronic circuit
or device. These pins are essentially your world. They cannot read any analog
inputs/outputs from components such as sensors. Some of the digital pins also have

additional features, such as support for peripherals such as Serial Peripheral
Interface (SPI) or JTAG.

A0 to A5 In contrast to the digital pins, there are an additional six GPIO pins; these
pins are the same as D0 to D7 except they are analog pins, which means they can