Links to resources about Alter Dog :

        project address:https://github.com/adeept/alter

 RobotGit:https://github.com/adeept/alter.git

20.1 Parts list

Electrical parts:

Copper pillar:

Screw:

Nut:

Wire:

Tool:

Own parts:

Screw color description:

In order to make the structural assembly process more intuitive, we dye the screws used in the product. During the assembly process, you can refer to the color of the fasteners in the tutorial to determine which type of screws and nuts to use.

The actual color of the product is subject to the product, and the actual screws are not colored.

Among them, the screws of M1.4x6 and M3x25 are very different, so we use silver in the tutorial without dyeing.

Name of aluminum alloy parts:

20.2Alter Dog Assembly Guide

1. Use M2x8 source screw and M2 nut to install AD002 servo to A02.

Install the rocker arm of AD002 servo. (You need to refer to the content of the assembly precautions to turn the servo gear to the middle position before installing the servo rocker arm. The rocker arm installation angle is approximately as shown in the figure. We will introduce the servo fine-tuning in the following chapters.)

    2. Use M3x6 countersunk screws and M3 nuts to install the battery box.

3. Use M2.5x8 screws and the self-tapping screws in the servo package to install L01 to the servo arm.

4. Use M3x8 screws and M3 locknuts to connect L02 and L01.

Use M3x12 screws and M3 locknuts to install L03 between L02 and L01.

Use M2.5x4 screws to install M2.5x6+6 copper pillars to A02.

Use M2x8 screws and M2 nuts to install the WS2812 LED to A02.

5. Install two small warm light LED to A02.

6. Use M2.5x14 copper pillars to install the Raspberry Pi to A02.(If the Raspberry Pi cannot be installed or the holes are not aligned, the reason is that the structure of the A02 is bent. You need to remove the battery box, and then use both hands to restore the bent and deformed A02 until it can be adjusted to fit the Raspberry Pi driver board.)

Use M2.5x10+6 copper posts to install the Robot HAT driver board on the Raspberry Pi.(The Raspberry Pi is not included in the kit.)

7. Use M1.4x6 tapping screws to install the blue ultrasonic module to A01.

8. Use M2x8 screws and M2 nuts to install the OLED screen to A01.

Use M2.5x10+6 copper pillars to install A01 to A02.

9. Use M2.5x4 screws to install A03 on A01.

Use M3x8 screws and M3 nuts to install C01 on A03.

10. Use M2x8 screws and M2 nuts to install the camera on C01.

11. Assembly is complete.

20.3 Wiring method

1. If you don't know how to connect the camera, you can refer to the official documentation of the Raspberry Pi camera.

2. There are four servos on the left side of Alter Dog's forward direction. The first servo from the front is connected to PWM-0.The second servo is connected to PWM-1. The third servo is connected to PWM-2. And the fourth servo is connected to PWM- 3; There are four servos on the right side of the forward direction. From the front to the back, the first servo is connected to PWM-4, and the second servo is connected to PWM-5, and the third servo is connected to PWM-6, and the fourth servo is connected to PWM-7.

3. The ultrasonic module is connected to the Ultrasonic port with a 4pin cable. Never connect the ultrasonic module to the IIC port, which will cause permanent damage to the ultrasonic module.

4. The WS2812 light bar is connected to the WS2812 port using a 3pin wire. It should be noted that the signal to control the light is sent by the Raspberry Pi and sent to the WS2812 light bar with the 3PIN wire by the driver board. It needs to be connected from the light bar with a white stripe (the interface text on the back of this end is marked with IN).

5. The OLED screen is connected to the IIC port of the driver board with a 4PIN wire.

6. MPU6050 is inserted into the 8PIN DuPont port on the front of the driver board.

7. Connect the power supply to the VIN port.

20.4 Tips for Structural Assemblage

Since many servos are used in the product, the servo installation is critical for the robot. Before installing the rocker arm to the servo, you need to connect the servo to power and make the servo shaft rotate to the central position, so the rocker arm installed at the designated degree will be in the central position.   

    Generally Raspberry Pi will auto run `webServer.py` when booting, when `webServer.py` will control all the ports connected to servos to send a signal of rotating to the central position. When assembling the servo, you can connect it to any servo port anytime. After connecting the servo to the port, the gears will rotate to the central position; assemble the rocker arm to the servo, disconnect the servo from the port, and insert more servos to repeat rocker arm assembly (all servos will be in the central position).  

    When the servo is connected to power, try moving the rocker arm. If it can't be moved, it indicates the program for the servo works; otherwise there's error for the servo program. Run the line `[RobotName]/initPosServos.py` (replace `[RobotName]` with the folder name of your robot's program) to make the servo rotate to the central position.  

    When booting (it may take 30-50s), it takes a while for the Raspberry Pi to control PCA9685 to set signal of all servo ports for central position rotating.

All the servo rocker arm installation angles shown in the document are the middle position of the servo. When the servo is turned on to the middle position, we install the servo rocker arm according to the angle shown in the document.

Note: All lock nuts involved in this document should not be tightened.

20.5 Tips for Power Provision

When you install the software, assemble the structure and debug the program, you can use a USB cable to power the raspberry pi. If the raspberry pi is installed with Motor HAT, you can connect the USB cable to the USB interface on the Motor HAT. Motor HAT will supply power to the raspberry pi through the GPIO interface.

The demand of different raspberry pi for electric current is different. For example, the raspberry pi 3B needs at least 2A of current to start up, and the raspberry pi 4 needs 3A to start up normally. You can check the specifications on your power adapter before you use the power adapter to power the raspberry pi.

When Motor HAT is connected to a load (such as connecting to a motor or multiple servos), you need to use a power supply that supports high current to connect to Vin on Motor HAT. You can use two 18650 batteries that support high current to power Motor HAT. Our product will provide a dual 18650 battery box with 2pin interface, you can directly connect it to Motor HAT.

When you use the USB interface on Motor HAT to supply power, Motor HAT's switch does not control whether to supply power, Motor HAT's switch can only control the power supply of Vin.

Do not use the USB interface and Vin on the Motor HAT to supply power at the same time. If you need to debug the program for a long time and do not want to remove the battery, you can set the switch on the Motor HAT to OFF. So, when using a USB cable to connect Motor HAT, Motor HAT is powered by USB.

If your robot restarts automatically after starting up or the robot disconnects and restarts suddenly when it starts moving after been started up normally, it is most likely because your power supply does not output enough current. When the robot is starting up, it will automatically run the program to put all the servos in the neutral position. The voltage drop caused by this process causes the raspberry pi to restart.

We have tested that when using 7.4V power supply, the peak current of the robot is about 3.75A, so you need to use a battery that supports 4A output.

You can also use a power lithium battery to power Motor HAT. Motor HAT supports the power supply that is below 15V.

You can use a USB cable to supply power to Motor HAT when the installing the rocker arm of the servo during structural assembly. After the robot software is installed, the raspberry pi will control Motor HAT to set all servo ports to output the neutral signal after it is started up. At this time, you can connect the servo to any servo port, the servo gear will turn to the neutral position, and then you can install the rocker arm of the servo according to the specified angle. After the rocker arm is installed, the servo can be disconnected from Motor HAT. When you need to install the rocker arm of the second servo, you only need to connect the second servo to any servo port on the drive board.

20.6 Alter Dog servo initial position adjustment

As Alter Dog's servo is used in a large number and has strict requirements on the initial angle of the servo, we need to adjust the center position of the Alter Dog servo. The previous installation process does not need to be installed strictly according to the angle, because the servo swing range in our program is only about 100°.

When we open the robot's WEB application, we find the following PWM INIT SET window. Here is the module we use to set the position of the servo.

When the mouse moves to the PWM box, there will be two up and down arrows. You can click these two arrows to select the servo you need to correct: the number shown is the servo connected to the corresponding PWM interface.

After selecting the servo to be adjusted, click "<" and ">" to change the angle of the corresponding servo. Since the numerical change in the program is relatively small, you may need to click multiple times to see the obvious servo rotation. When the servo swings vertically downward (as shown in the figure below),we click SETPWM to save the settings. After saving the settings, we adjust the next servo, and so on, until all the servos 0 to 7 are adjusted.

As shown in the figure above,Press "<"AND">" to swing its rocker arm to the vertical position, and then click SETPWM, and the No. 0 servo is adjusted. You need to adjust all 8 servos from No. 0 to No. 7 to be vertical. After restarting the robot, Alter Dog can move normally.

The last gear icon means to return all servo settings to the initial default values.