> For the complete documentation index, see [llms.txt](https://docs.idew.org/code-internet-of-things/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.idew.org/code-internet-of-things/tutorials/hello-world-test/2.1-start-iot-device.md).

# B-1 Start IoT Device

Let's start your Photon to verify it connects to Wi-Fi and Particle Cloud.

## Power On Photon

Start your Photon by powering on the circuit board:

* Connect a power cable into the barrel jack or Micro-USB port on the circuit board, and connect the other end of the cable to a power source (such as:  battery, computer USB port, etc.).

{% hint style="success" %}
**CHOOSE ONE:**  Only **one** power source (barrel jack or Micro-USB) needs to be connected.
{% endhint %}

{% hint style="info" %}
**REMINDER:**  The Photon circuit board does **not** have an "on/off" switch. As soon as a power source is connected to its barrel jack or Micro-USB port, the Photon will power on and start running. To turn off the Photon, you have to disconnect its power source.
{% endhint %}

Once the circuit board has power, you should see its red Power LED light turn on.

You should also see the RGB LED light turn on – it will blink green while the Photon automatically tries to connect to Wi-Fi.

Once the Photon has successfully connected to Wi-Fi and Particle Cloud, the RGB LED will be cyan (light blue) and "breathing" (slowly blinking).

{% hint style="warning" %}
**CONNECTION ISSUES:**  If your Photon is having issues (can't connect to Wi-Fi, etc.), you'll see a [different RGB pattern](https://docs.idew.org/code-internet-of-things/tutorials/meet-your-iot-kit/1.1-circuit-board#normal-rgb-patterns) (such as:  breathing green, breathing pink, etc.). You may have to consult with your teacher to troubleshoot your device.
{% endhint %}

## How does Photon connect to Wi-Fi?

When your Photon is powered on (or restarted), it will automatically try to connect to a Wi-Fi network.  It does this by using its saved list of Wi-Fi logins (network names and passwords). Every Photon can be programmed to store login information for up to 5 different Wi-Fi networks.

A brand new Photon will **not** have any Wi-Fi logins saved yet. However, the Photon provided to you by your teacher will most likely already have a Wi-Fi login programmed into it.

## What is Particle Cloud?

Once your Photon is connected to Wi-Fi, the Photon will automatically try to connect to Particle Cloud, which is a cloud service that Particle provides for all of its microcontroller devices. All of your Photon's internet communications are routed through Particle Cloud.

Particle Cloud can be used to:

* Code and store all your different Photon device apps (using Particle Build code editor)
* Update the app stored on your Photon device
* Update the firmware on your Photon device
* Send and receive data between your Photon device app and your web app
* Manage your Photon device remotely

![](https://content.gitbook.com/content/6i7JP4OaydCjQ76D1bQc/blobs/jYkpJc1X6C8VeTr5FFlK/particle-cloud.png)

{% hint style="info" %}
**SETUP NEW DEVICE:**  The Photon device provided to you by your teacher should **already** be setup with a Wi-Fi login and Particle account that you will use. If **not**, then the Photon will need to be [setup as a new device](https://docs.particle.io/guide/getting-started/start/photon/#connect-your-photon) by programming it with a Wi-Fi login, creating a Particle account, and adding the device to your account by claiming its device ID.
{% endhint %}