# Operate MR-Buggy 3 using NavQPlus and FMURT6 ## Introduction This tutorial describes how to operate [MR-Buggy 3](https://nxp.gitbook.io/nxp-cup/mr-buggy3-developer-guide-2022/getting-started) with [Logitech Joystick](https://www.logitechg.com/en-in/products/gamepads/f310-gamepad.940-000112.html?searchclick=logi) using [NavQPlus](https://nxp.gitbook.io/8mpnavq/) and [FMURT6](https://www.nxp.com/part/RDDRONE-FMURT6#/). The [synapse](https://github.com/CogniPilot?q=synapse\&type=all\&language=\&sort=) packages from [CogniPilot](https://github.com/CogniPilot) are built on NavQPlus which will read input from the Joystick and send the appropriate commands to FMURT6 over ethernet. The [mrbuggy](https://github.com/CogniPilot/cerebri/tree/main/app/mrbuggy3) application in [CogniPilot/cerebri](https://github.com/CogniPilot/cerebri/tree/main) running on FMURT6 takes commands from NavQPlus and sends operation signals to MR-Buggy 3 servo and motor controller. ## Items Needed

S. No.	NAME	QUANTITY
1	RDDRONE-FMURT6	1
2	Pixhawk Debug Adapter	1
3	J-Link EDU Mini	1
4	JST SH 10-Pin Cable	1
5	USB-C (Male) to USB-A (Male) Cable	4
6	Micro-USB (Male) to USB-A (Male) Cable	1
7	.05" 10-Pin Ribbon Cable	1
8	MR-Buggy 3 Kit	1
9	Logitech G F310	1
10	USB-A (Female) to USB-C (Male) Adaptor	1
11	NavQPlus	1
12	Cat6a (Male) ix Industrial to RJ45 (Male) Ethernet Cable	1
13	USB-UART serial debugger	1
14	E3648A 100W Dual Output Power Supply	1
15	JST GH 1.25mm Pitch 2 Pin Cable (Female to Female)	1
16	JST GH 1.25mm Pitch 6 Pin Cable (Female to Female)	1

## Hardware Procedure

Block Diagram of the Complete Hardware Setup

Pixhawk Debug Adaptor and J-Link EDU Mini

#### Power Supply Setup 1. Press "Power" Button. 2. Press "Output On/Off" Button. 3. Select "Voltage" from "Voltage/Current" Button. 4. Set the Voltage to 7.4 V from the "Tuning Nob." 5. Connect the output wires to XT60 M1 on buggy.

## FMURT6 Software Procedure (on host machine) #### Prerequisites 1. Unrestricted network connection 2. [Ubuntu 22.04](https://releases.ubuntu.com/jammy/) on native machine 3. Setup ssh keys ``` sudo apt update sudo apt upgrade sudo apt install git ``` #### Software Setup ``` mkdir -p ~/git/cognipilot/ cd ~/git/cognipilot/ git clone git@github.com:CogniPilot/helmet.git cd helmet ./scripts/install.sh -f dream/mrbuggy3.yaml ``` {% hint style="info" %} Type "y" + "enter" when required. {% endhint %} ``` source ~/.bashrc source ~/.profile ``` #### Building and Flashing ``` cd ~/git/cognipilot/ws/cerebri/app/mrbuggy3 west build -b mimxrt1062_fmurt6 -p ``` {% hint style="info" %} Download and install Jlink from: {% endhint %} ``` west flash ``` {% hint style="warning" %} If you get an error with "west flash," make sure J-Link EDU Mini is directly connected to your machine. If that doesn't work then unplug and re-plug the FMURT6 board. {% endhint %} ## NavQPlus Software Procedure (on navq+ board) #### Prerequisites 1. [Ubuntu 22.04.3 Humble Image](https://github.com/rudislabs/navqplus-create3-images/releases/tag/v22.04.3) 2. Unrestricted network connection 3. Setup ssh keys {% hint style="info" %} NavQ+ requires internet connection for the following setup. If an ethernet connection is not available, connect the board to the native ubuntu machine via ethernet and [create a network bridge from wifi to ethernet on your machine](https://amigotechnotes.wordpress.com/2019/01/25/share-usb-tethering-to-wifi-and-ethernet-devices/). {% endhint %} #### Accessing Shell ``` minicom -D /dev/ -b 115200 ``` {% hint style="info" %} username=user password=user {% endhint %} #### Software Setup ``` sudo apt update sudo apt upgrade sudo apt install ros-humble-actuator-msgs mkdir -p ~/git/cognipilot/src cd ~/git/cognipilot/src git clone git@github.com:CogniPilot/synapse_ros.git git clone git@github.com:CogniPilot/synapse_msgs.git git clone git@github.com:CogniPilot/synapse_protobuf.git git clone git@github.com:CogniPilot/synapse_tinyframe.git cd ~/git/cognipilot colcon build --symlink-install ``` {% hint style="warning" %} Comment out both the interfaces listed in \~/CycloneDDSConfig.xml; {% endhint %} #### Network Setup ```` sudo vi ~/.net.sh ``` (Add the following lines in ~/.net.sh) #!/bin/bash sudo ethtool -s eth0 master-slave forced-slave sudo ifconfig eth0 192.0.2.2 netmask 255.255.255.0 ``` ```` {% code fullWidth="false" %} ``` echo "bash /home/$USER/.net.sh" >> ~/.bashrc source ~/.bashrc ``` {% endcode %} ## Running and Demonstration #### Execution on NavQPlus {% hint style="info" %} Since, ros2 commands block the shell, we will need two shells for the following. {% endhint %} ``` ros2 run joy joy_node --ros-args -r /joy:=/cerebri/in/joy cd ~/git/cognipilot/install source setup.bash ros2 launch synapse_ros synapse_ros.launch.py ``` {% hint style="warning" %} If the TCP connection fails, reset FMURT6. {% endhint %} #### Operation from Joystick

1. Set the Joystick to X-Input Mode (from the switch behind the controller). 2. Press the mode button such that the green light next to it is turned on. 3. Press green button A (0) to select manual mode. 4. Press start button (7) to arm in the selected mode. 5. Use vertical d-pad axis (1) for acceleration/reverse. 6. Use horizontal right-stick axis (3) for steering. 7. All controls: joy axes 1 is throttle, joy axes 3 is yaw/steering, button 7 is arm, button 6 is disarm, button 1 is mode manual, button 1 is mode auto, button 2 is mode cmd\_vel.