Gunnar

Gunnar and a sample map generated with Gmapping.

Gunnar is a differential-drive rover with LIDAR as its primary sense. It uses Robot Operating System (ROS) to provide messaging between components, and important algorithms such as particle filter simultaneous localization and mapping (SLAM).

To make the SD card:

1. Download and extract Raspbian Jessie image (e.g. 2016-05-27-raspbian-jessie.img, which I torrented from raspberrypi.org; see /data/).

2. Create config script makeconfig.mk. Mine looks like this:

    IMGPATH = /home/tsbertalan/workspace/gunnar/2016-05-27-raspbian-jessie.img
    MNTPOINT = /mnt/img
    USER = pi
    SDX = /dev/sdc
   

   Here, the MNTPOINT is where the image will be mounted for modification, and the USER is the username to be used on that system (I don't know why it wouldn't be pi). THE SDX MUST BE THE SD CARD YOU WILL BE OVERWRITING. If you don't get this right, you might OVERWRITE YOUR INTERNAL HARD DRIVE with the Raspbian image.

3. Mount image, alter it to contain our backdoor, and unmount (script mountAndAlterSD.sh).

4. Write image (make targets flash and verify). This takes about 3 minutes on my machine, with a 32 GB Samsung

5. Insert SD into Raspberri Pi. Boot and wait for the script to install things and self-reboot. This sometimes takes more than an hour on my Pi 3B v1.2 with 62 Mbps wifi download speeds, mostly in the "Unpacking libboost1.55-dev:armhf" stage. However, 20 minutes is a more likely duration. Monitor the process on the HDMI output--if there's an immediate kernel panic, reflash the card. Try using tail -f /var/log/syslog | grep bootInstall to monitor progress or diagnose errors.

6. If you're able to SSH in, test functionality by roslaunch gunnar gunnar_hardware.launch

Here's a video of Gunnar autonomously navigating to user-selected waypoints, mapping along the way.

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