Steps to assemble the APP4MC Racecar
#####################################


This document provides the steps to assemble and mount the components on Traxxas based RC car chassis to realize APP4MC Racecar.

Remove the default ESC
=======================

Firstly, remote the mounted radio-controlled unit and the default ESC mounted on the chassis.
Replace the front spring with the stiffer springs.
Also, remove the nerf connectors available on either side of the RC car.

.. image:: ../../images/traxxas1.jpg
        :align: center
        :scale: 15 %

Place the LiPo battery in the slot provided on the Traxxas chassis.


Mount standoffs on chassis
===========================

Mount 50 mm and 45 mm standoffs as shown in figure below.
Make use of 6 mm M3 screws to mount them on the chassis.

.. image:: ../../images/traxxas2.png
        :align: center
        :scale: 80 %


Mounting sensors on upper deck
===============================

Take the front section of the upper deck platform and mount the ZED2 camera using 10mm M3 screws.
Next, mount the RPLiDAR on 30 mm M3 standoffs.
The standoffs can then be fixed with the upper deck using 10 mm M3 screws.
The top view of the assembled sensors on upper deck platform is shown below: 

.. image:: ../../images/traxxas3.jpg
        :align: center
        :scale: 10 %


The side view is depicted in the below figure:

.. image:: ../../images/traxxas3_1.png
        :align: center
        :scale: 100 %

Lower deck Assembly
====================

The lower deck platform consists of VESC, Nvidia AGX Xavier and Beaglebone AI.

* Step 1 - Mount the VESC at the bottom side of the lower deck platform using 30 mm M3 screws.
* Step 2 - Fix the cable headers for connecting VESC with servo motor and Beaglebone AI.


.. image:: ../../images/traxxas4.jpg
        :align: center
        :scale: 15 %

The top view of the front section of

* Step 3 - Fix the support platform with the help of 25mm M3 grub screws.
* Step 4 - Mount the Beaglebone AI using 5mm M3 standoffs and 30 mm M3 screws.

The final version of front section of lower deck platform is shown below:

.. image:: ../../images/traxxas4_1.png
        :align: center
        :scale: 80 %

* Step 5 - Remove the 30 mm screws used to mount the Nvidia Xavier AGX developer kit on a platform.
* Step 6 - Place the rear section of the lower deck on the assembled lower deck platform consisting of Beaglebone AI and VESC.
* Step 7 - Mount the Nvidia AGX xavier using 40 mm screws.

The entire lower deck platform with the mounted components is displayed below:

.. image:: ../../images/traxxas4_2.png
        :align: center
        :scale: 80 %

Also add the 50 mm standoffs to the front section of lower deck in order to support the uppwer deck.
Additional a 35 mm standoff is added on the front section of the chassis. 
The next step is to mount the lower deck on the chassis.
This can be done by fixing the standoffs on the chassis with the M3 screws on the M3 holes provided on lower platform deck.


.. image:: ../../images/traxxas4_3.jpg
        :align: center
        :scale: 15 %

* Step 8 - Establish the wire connections between Beaglebone AI, VESC, Servo motor, Jetson AGX Xavier and BLDC motor.

.. list-table:: Pin connection between Beaglebone AI and VESC
   :align: center
   :widths: 300 700
   :header-rows: 1

   * - Beaglebone AI
     - VESC
   * - P9.13(UART Tx)
     - RX
   * - P9.11(UART Rx)
     - TX
   * - P9.2(GND)
     - GND


* Step 9 - Mount the Waveshare SN65HVD230 on either side of the platform deck and fix them using zip ties.

.. list-table:: Pin connection between Beaglebone AI and VESC
   :align: center
   :widths: 450 300 300
   :header-rows: 1

   * - Waveshare SN65HVD230
     - Beaglebone AI
     - Nvidia Jetson AGX Xavier
   * - CAN TX
     - P9.26(CAN TX)
     - Pin 31
   * - CAN RX
     - P9.24(CAN RX)
     - Pin 29
   * - GND
     - P9.1(GND)
     - Pin 30
   * - VCC(3.3 V)
     - P9.3(3.3 V)
     - Pin 1


Mounting the upper deck
========================

* Step 1 - Mount the front section of the upper deck on the lower deck platform
* Step 2 - Mount the standoff on the rear section of the upper deck.
* Step 3 - Fix the the Patona power bank to battery mount using double sided tape.
* Step 4 - Mount the active USB hub at the slot provided on upper deck. 
* Step 5 - Mount the battery mount on the rear section of the upper deck.

The final assembled APP4MC Racecar is shown in below figure.

.. image:: ../../images/traxxas5.jpg
        :align: center
        :scale: 15 %

A TypeC-to-TypeA USB converter is used to power the Beaglebone AI from active USB hub.
The active USB is powered from the 5V USB port available on Patona power bank.
The power bank also comes with a set of connectors that is used to power the Nvidia AGX Xavier.
The ZED2 camera is directly powered using the Nvidia AGX Xavier whereas the RPLiDAR is connected to AGX Xavier using a TypeC-to-TypeA female converter.
Additionally, the RPLiDAR is powered on using the active USB hub.
The cable management is done using zip ties around the holes and grooves created on the platform deck.