RoboScope

System Diagram

Network Configuration

Method 1 - Connect through a Router

• Both Grasshopper computer and Raspberry Pi connect to a router.
• Check IP address of the Raspberry Pi.

Method 2 - Connect through Ethernet cable

• Connect Grasshopper computer and Raspberry Pi via a Ethernet cable directly and follow the cofiguration below to set up a network:

  Device	IP	Mask	Gateway
  Grasshopper computer	192.168.0.2	255.255.255.0	0.0.0.0
  Raspberry Pi	192.168.0.1	255.255.255.0	0.0.0.0

Rhino Grasshopper

Install Plugin

1. Networking plugin: gHowl can be downloaded from here. And check this instruction to install the plugin.

Set up Raspberry Pi IP address on Grasshopper

Here we assume that Raspberry Pi is hosted at 10.100.2.97

CanbusController (run at Raspberry Pi)

Installation

sudo apt-get install can-utils
cd CanbusController
pip3 install -r requirements.txt

Quick Start

1. Plug in CANDO and start interface.

   sudo ip link set can0 up type can bitrate 1000000

2. Start UdpServer2CANbus.py service.

   Here, we assume the ip of Raspberry Pi is 192.168.0.1, and the ip address of Grasshopper computer is 192.168.0.2

   ./UdpServer2CANbus.py -i 192.168.0.1 -p 5005 -gi 192.168.0.2 -gp 5005 -c can0

3. You can see CAN bus raw data by:

   candump can0

4. Drag slider bars (in Grasshopper) then you will see something similar to this:

   

Record CAN bus message

1. Setup SocketCAN interface on can0 with bitrate 1 Mbps.

   sudo ip link set can0 up type can bitrate 1000000

2. Record CAN log.

   candump -L can0 > can.log

UDP data format

We use JSON format to transmit data between Grasshopper and Raspberry Pi.

{
    "data": [
        {
            "position": {
                "x": 0, // row 
                "y": 0  // column
            },
            "height": 10
        },
        {
            "position": {
                "x": 0,
                "y": 1
            },
            "height": 20
        }
    ]
}

CAN Bus ID and Filter setting

ID mapping

A row-major order is adapted in this system. A ID in a $n\times n$ matrix system can be calculated with: $$ID = nx+y+\theta$$ $\theta$ is the offset of CAN ID (default $\theta=$ 0x100)

Filter setting

Device	ID	Mask
Raspberry Pi	0x000	0xF00

Component Testing

Send JSON to Grasshopper through UDP

We assume the ip address of Grasshopper computer is 192.168.0.2.

cd CanbusController/test
./Json2UdpClient.py -i 192.168.0.2 -f grasshopper_output.json

Send recorded CAN bus data to Grasshopper through UDP

1. Start service

   cd CanbusController
   ./Json2UdpClient.py -i 192.168.0.2 -f grasshopper_output.json -c vcan0

2. Play recorded CAN bus data on vcan0.

   cd CanbusController/test
   canplayer vcan0=vcan0 -I ./CanbusController/test/can2udp.log

Send recorded CAN bus data to control RoboScope

1. Setup SocketCAN interface on can0 with bitrate 1 Mbps.

   sudo ip link set can0 up type can bitrate 1000000

2. Play CAN log.

   canplayer can0=vcan0 -I ./CanbusController/test/udp2can.log