# Hardware Overview

## Introduction

The Milieu Babel tank was recently upgraded in order to continue testing our multi-agent networking solutions. Currently, the hardware consists of:

* SEEED ODYSSEY - X86J4105800
* YDLIDAR G2B
* Intel Realsense D435i 

## Initial Benchmarks

The initial benchmarks for this device were determined by measuring the frequency of the node messages locally on the board. These measurements were obtained by using the `rostopic hz` command while remotely connected to the board. As such, these measurements do not reflect the amount of time it took to broadcast them to other devices on the LAN. Based off of a replay of a `rosbag` file recorded locallly on the robot, we can see that the stream from the camera is recorded at about 30 fps.

| Topic Name               | Type                   | Description                                     | Average Hz |
| ------------------------ | ---------------------- | ----------------------------------------------- | ---------- |
| /scan                    | sensor\_msgs/LaserScan | Laser Scans from the LIDAR Sensor               | 10.136     |
| /camera/color/image\_raw | sensor\_msgs/Image     | The RGB Camera Stream from the Realsense Camera | 29.765     |
| /camera/gyro/sample      | sensor\_msgs/Imu       | The odometry information from the gyroscope     | 399.908    |
| /camera/accel/sample     | sensor\_msgs/Imu       | The odometry information from the accelerometer | 255.985    |

### Camera Startup Instructions

With a ROS Master already running on the board, run this command:

```bash
roslaunch realsense2_camera rs_camera.launch enable_accel:=true enable_gyro:=true
```