> For the complete documentation index, see [llms.txt](https://cavedu.gitbook.io/linkit-7697/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cavedu.gitbook.io/linkit-7697/linkit-7697-development-guide-for-arduino-ide/developer-guide/fota-update.md).
# FOTA Update
**FOTA** stands for Firmware Over the Air, allowing you to update the on-board sketch binary using Wi-Fi.
The **LHTTPUpdate** library allows you to download a **FOTA binary** from a given **HTTP** URL, and apply it to LinkIt 7697.
### Example
* Upgrade your LinkIt 7697 Arduino BSP to **v0.10.5** or later version.
* Select **LinkIt 7697** from **Tools > Board** menu.
* Open **Examples > LHTTPUpdate > LHTTPUpdate**
* Change the **ssid** and **pass** according to your Wi-Fi AP setting:
```
char ssid[] = "yourapssid"; // your WPA2 network SSID (AP name)
char pass[] = "yourpassword"; // your WPA2 network password
```
* Click **Upload** to upload the sketch to LinkIt 7697
* After upload, open the **Serial Monitor**
* You should see the following message:
```
HTTPUpdate example begins.
Attempting to connect to SSID: yourssid
Connected to wifi
Begin downloading new firmware
Press RST key to reboot to updated firmware version.
After reboot, it may take a while to update the firmware.
The USR LED lights up during the update process.
```
This means the example is now downloading the new binary from the URL
* Press **RST** button to reboot and replace on-board binary with the downloaded sketch binary(fota\_example.bin)
* It may take sometime for the update process to complete. After complete, the board starts blinking - and the on-board sketch binary is now updated.\
### How It Works
The sketch downloads the "**FOTA binary**" from , using the following call:
```
fotaUpdater.update(fotaBinaryURL);
```
The **FOTA binary** is a processed sketch binary. It is compressed and checksum to ensure that corruptions can be detected during the update process.
During the **update()** method, the FOTA binary is written in to the **FOTA region** of the on-board flash. The on-board flash layout is shown below:
After finish downloading the **FOTA** **binary**, the **update()** method flags the **FOTA** **region** as ready to update.
After the system reboots, the **bootloader** detects new binaries in the FOTA region, uncompress and verifies it, and write the new binary to the **CM4 firmware** region.
And completes the FOTA operation.
### How to Generate FOTA Binary
As we mentioned, the **FOTA binary** is a processed sketch binary. You can follow these steps to generate the FOTA binary:
* Download the **FOTA ROM Package** tool from .
* Export your sketch binary by selecting **Sketch > Export Compiled Binary** from the IDE menu.
* Follow the instruction of the **FOTA ROM Package** to process the sketch binary. We show the instructions of the Windows version below.
#### Windows FOTA ROM Package Tool
We denote the FOTA ROM Package root folder as **$FOTA\_ROOT**.
* Copy **$FOTA\_ROOT\\\_ini\template\mt7697\FOTARomPacker.ini** to **\_ini**
* Modify **$FOTA\_ROOT\\**\_ini\FOTARomPacker.ini
```
[General Setting]
Base_Directory=.\_Load\mt7697
[CM4 bin]
File=fota_example.bin
Start_Address=0x79000
Partition_Size=0x1ED000
Is_Compressed=true
```
Modify the **File** attribute.
{% hint style="danger" %}
**Do not** change the **Start\_Address**, **Partiion\_Size** and **Is\_Compressed** option. These settings must match the flash layout of LinkIt 7697.
{% endhint %}
* Copy the sketch binary to **$FOTA\_ROOT\\\_Load\mt7697**
* Execute the script **gen\_image.bat**
* The generated FOTA binary is located in the **\_Output** folder
After generating the FOTA binary, you can then host the binary in a HTTP server and use **LHTTPUpdate.update()** to download and apply the FOTA binary.