# 2 🧩 Open the Box

<figure><img src="https://2275978772-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MPQ2vWEZUH7ol6XE55o-887967055%2Fuploads%2FkDFWa0Ip8z1QiZz2MJre%2Fcompare1.jpeg?alt=media&#x26;token=7fb9cec1-5dc5-4df1-86f6-b205801c5258" alt=""><figcaption></figcaption></figure>

## 2.1 Pre-assembled Bittle

{% embed url="<https://youtu.be/C63_iGDrAro>" %}

{% hint style="info" %}
Video timeline:&#x20;

00:12 Install the neck&#x20;

01:28 Install the battery&#x20;

02:05 Bend the legs&#x20;

03:15 Open the back cover&#x20;

04:07 Insert the Bluetooth dongle (only for models with NyBoard)&#x20;

05:05 Connect the mobile app
{% endhint %}

If you received the pre-assembled Bittle, you need to insert the neck into the body and **bend the knees to natural angles**. Drag the curly wire from the knee side to the shoulder side to avoid squeezing when the knee joints rotate. Put the joints into the following posture before turning on the power.&#x20;

![Pay attention to the direction of the head and the joints](https://2275978772-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MPQ2vWEZUH7ol6XE55o-887967055%2Fuploads%2FcYp1HZIsev3wtGGLLaHs%2FBittle_Bootup_Pos_en.png?alt=media\&token=cc1ee276-09d7-475a-acab-61756c057a3a)

**Long press** the battery's button for 2\~3 seconds to power on/off. **Unplug the insulation sheet** of the infrared remote's battery, then you can [control Bittle to move](https://docs.petoi.com/infrared-remote/remote-controller). The robot will keep pausing its movements with beeping sounds when the battery is low. Then, you need to [charge the battery](https://docs.petoi.com/technical-support/battery) with a 5V micro-USB cable. Considering safety, the battery won't supply power during charging.&#x20;

![](https://2275978772-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MPQ2vWEZUH7ol6XE55o%2F-MSlETzchbkCW7zUttjH%2F-MSmyAEyBm8iJJ42uyMK%2F_B2L7991.JPG?alt=media\&token=7cad961e-3c1b-4a07-bccc-99afefd2de3e)

{% hint style="warning" %}
If your Bittle's lower leg is in the right direction but doesn't move when calibrating, you may rotate it in the right direction. You should feel moderate resistance until the joint locks at the right position. The cause is that the new gears are a little too tight, and the large bootup resistance will trigger the protection algorithm. The servo will reduce the force on the joint to avoid overcurrent, which will stop the joint from moving.
{% endhint %}

### **Buzzer beep meaning:**

{% hint style="info" %}
\[1].  The startup melody in normal mode starts at **00:13** in the video below.

\[2]. The repetitive melody starts at **00:21** in the video below.

{% embed url="<https://www.youtube.com/watch?v=DrSsbd84ryo>" %}
{% endhint %}

<table><thead><tr><th width="199.10714285714286">Sound type</th><th>Occasion</th><th>Explaination</th></tr></thead><tbody><tr><td>Short melody [1]</td><td>Power on or reboot</td><td>The program starts successfully</td></tr><tr><td>Short beep</td><td>During use</td><td>The program receives a command</td></tr><tr><td>Repetitive melody [2]</td><td>During use and pausing the movements</td><td>The battery is low or disconnected</td></tr></tbody></table>

### Mute/Unmute the buzzer beep

For the mainboard - NyBoard, you can mute/unmute the buzzer beep by serial command **b** in the serial monitor.

Please refer to [the instructions](https://docs.petoi.com/arduino-ide/upload-sketch-for-nyboard#id-6.-open-the-serial-monitor) in the Petoi Doc Center for how to open the serial monitor and input the serial command.

You can also use the serial command in the [mobile app](https://docs.petoi.com/mobile-app/controller#mute-unmute-the-buzzer-beep) by creating a single command:

<figure><img src="https://2275978772-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MPQ2vWEZUH7ol6XE55o-887967055%2Fuploads%2FbAxk2JTIVs6aDD0Lm6Gb%2F%E8%B0%83%E8%8A%82%E9%9F%B3%E9%87%8F%E5%91%BD%E4%BB%A402.jpg?alt=media&#x26;token=1ee4a2c7-1e75-4483-8203-6c743bda912f" alt=""><figcaption></figcaption></figure>

You can skip Chapter 3 **Assemble the Frame,** Chapter 4 **Connect Wires**, and Chapter 5 **Board Configuration**. Go to Chapter 6 [**Calibration**](https://bittle.petoi.com/6-calibration) directly. You may need to open Bittle's back cover to insert the Bluetooth dongle.&#x20;

{% hint style="warning" %}
**The pre-assembled Bittle is only coarse-tuned.** You still need to calibrate Bittle's joint servos and final assembly to fine-tune its joints for the best performance.&#x20;
{% endhint %}

{% hint style="warning" %}
Friction plays an important role in dynamic balancing during walking. Though the silicone toe covers (socks) can improve grip, they will also amplify the differences of the unpredictable surface of your test environment. So for regular use, we recommend running Bittle without the socks, unless you can tune the gait or need friction to perform some specific tasks.
{% endhint %}

## 2.2 Bittle Construction Kit

If you order a Bittle Robotics Kit Construction or BIttle STEM Kit Construction, you will build your robot dog. You will learn more about robotics after understanding the design logic behind Bittle. Please move to the next chapter for details.&#x20;