# 4. Expansion Course-Import Custom Music

## 4.1 Objective 

In this section, you will learn how to read from and write to the robot's built-in TF card in order to play custom music while executing an action group.

## 4.2 Implementation 

:::{Note}
* During the procedure, it requires removing the four screws on the robot's back cover. After completing the operation, re-install the back cover.
* If you are using a new TF card, ensure that its capacity does not exceed 32 GB.
:::

(1) Rename your custom audio file, and the controller supports MP3/WAV formats. The filename format is: [Four-digit Action Group Number] + [Song Name] with no spaces between the number and the name. For example, if Action Group 40 will be paired with the song The Most Dazzling Folk Style, rename the file to: 0040TheMostDazzlingFolkStyle If the action group number is less than four digits, pad it with leading zeros.

(2) Locate and remove the TF card from the controller, please refer to the diagram below for position.

<img src="../_static/media/chapter_4/image1.png" class="common_img" style="width:500px;"/>

(3) To transfer the audio file, first insert the TF card into a card reader, then copy the renamed audio file into the **"MP3"** folder on the TF card. After importing, the TF card should contain files exactly as shown in the example below.

:::{Note}

Files placed in other folders or in subfolders within the **"MP3"** folder cannot be read correctly.

:::

<img src="../_static/media/chapter_4/image2.png" class="common_img" />

(4) Re-insert the TF card into the control board and re-attach the back cover. Run Action Group 40 to enjoy the robot's music and dance performance.