SmartWheels

Set up the Raspberry Pi

1. Download Raspbian Jessie from here.
2. Mount the image onto an SD card using these instructions.
3. Follow the on-screen instructions to set up Raspberry Pi.
4. Run sudo raspi-config and set locale, timezone, keyboard (GB => US).
5. Update packages with sudo apt-get update followed by sudo apt-get upgrade.
6. Install git with sudo apt-get install git.

R-NET Setup

Clone Stephen Chavez's repository

git clone https://github.com/redragonx/can2RNET

Install can-utils

sudo apt-get install can-utils

Add the following lines to /boot/config.txt

dtparam=spi=on
dtoverlay=mcp2515-can0,oscillator=16000000,interrupt=25
dtoverlay=spi-bcm2835

Add the following lines to /etc/network/interfaces

allow-hotplug can0
iface can0 can static
    bitrate 125000
    up /sbin/ip link set $IFACE down
    up /sbin/ip link set $IFACE up

Add these kernel modules to /etc/modules

mcp251x
can_dev

Boot with everything connected and run

python3 JoyLocal.py

SSH to Raspberry Pi

1. Connect the computer to a WiFi network. Since CalVisitor doesn't support local SSH and AirBears2 is difficult to set up on the Raspberry Pi, we use enable a Personal Hotspot on an iPhone (Settings > Personal Hotspot) to use as our local WiFi network.
2. Connect Raspberry Pi to the same WiFi network using these instructions.
3. SSH using these instructions.
4. (Optional) Set up a permanent IP address for the Raspberry Pi using either this link or the second comment in this link. Not sure which one did the trick.
5. (Optional) Enable password-less SSH by copying the contents of the computer's id_rsa.pub file to the Raspberry Pi's ~/.ssh/authorized_keys file.

AprilTags on iPhone to Raspberry Pi

1. Download the AprilTag application on the iPhone.
2. Tap the yellow text on the top left corner to go to settings, enter the Raspberry Pi's IP address into the "UDP Transmit Addr" field, and turn on the "UDP Transmit Enabled" switch.
3. Receive the UDP packets on port 7709 according to the AprilTags wiki. See their example decoder written in Java here.

Discontinued Instructions

AprilTags on Raspberry Pi

RaspiCam

Install OpenCV so that RaspiCam compiles with OpenCV compatibility

sudo apt-get install libopencv-dev

Clone repository (fixes BGR issues from original SVN repository)

git clone https://github.com/6by9/raspicam-0.1.3

Following these instructions...

cd raspicamxx
mkdir build
cd build
cmake ..

Verify that -- CREATE OPENCV MODULE=1 in the output, then run

make
sudo make install
sudo ldconfig

AprilTags

Following these instructions...

Install dependencies

sudo apt-get install subversion cmake libopencv-dev libeigen3-dev libv4l-dev

Clone repository

git clone https://github.com/ysshah/SmartWheels.git

Compile and run

cd SmartWheels
make
./build/bin/apriltags_demo

Installing OpenCV and Python

Follow this OpenCV guide and then this Python with camera guide.