Page 177 - Programming the Photon Getting Started With the Internet of Things

There are a couple of reasons why this may occur:

You have set your module to manual or semi_automatic in your user firmware

You have called wifi.off() in your user firmware program

Listening mode This is probably the most important mode you will encounter.
When the Photon board is in Listening mode, it is waiting for your input to connect
to the Wi-Fi network. The Photon needs to be in Listening mode in order to begin
connecting with the smart phone app or over universal serial bus (USB). To put the

Photon board in Listening mode, simply hold down the SETUP button for three
seconds until the RGB LED begins to flash blue.

Wi-Fi network reset To erase the Wi-Fi network on the Photon board, hold down
the SETUP button for about 10 seconds until the RGB LED rapidly flashes blue.
Alternatively, you can hold down the SETUP button and tap the RESET button
while doing so until the RGB LED turns white.

Safe mode Safe mode connects the device to the cloud but does not run any

application firmware program. This mode is one of the most useful for development
or for troubleshooting. If something has gone wrong with the app or firmware you
have loaded onto your Photon board, you can set your device to Safe mode. This
runs the device’s system firmware but doesn’t execute any application code, which
can be useful if the application code contains bugs that stop the device from

connecting to the cloud. The Photon board indicates that it is in Safe mode when the
LED blinks magenta. To put your Photon board in Safe mode, hold down both
buttons in the board and release the RESET button while keeping the SETUP button

held down until it flashes magenta release the setup button. The Photon board will
then enter Safe mode if there is no application code flashed to the board or when the
application firmware is invalid.

Device firmware upgrade If you want to program your Photon board with a custom
firmware through USB, you will need to use this mode. This mode triggers the on-
board bootloader that accepts firmware binary files through the dfu utility program.

To enter the Device Firmware Upgrade mode, you need to hold down both buttons
and release the RESET button while keeping the SETUP button held down. Wait
until the LED starts flashing yellow and then release the SETUP button.

Troubleshooting Modes

Wi-Fi module not connected If the Wi-Fi module is on but not connected to the

network, your Photon with blink blue. This will be a dark blue, not a cyan color.
Cloud not connected When the device is connected to a Wi-Fi network but not to

the cloud, it will blink green.
Bad public key When the server public key is bad, the Photon board will flash

alternating colors of cyan and red. A red flashing LED can indicate the following