Debugging WiFi

To rule out the obvious, make sure you are on ut-wpa2 (has to be this one) and that your internet connection is functioning. Make sure to allow the robot at least one full minute to complete the boot process and connecto to ut-wpa2.

First and foremost, reboot the robot. While the underlying issue can usually be something specific, this often fixes some of the basic problems.

USB shell

If this step doesn't work, you will need to shell in through the USB connector. Shelling in through Ethernet will not work because an Ethernet connection prevents WiFi from attempting to initialize. To shell in through USB, follow these steps:

1. Power down the robot through the clean shutdown procedure (https://github.com/utk-robotics-2016/utk-robotics-2016/wiki/Beaglebone#clean-shutdown)
2. Flip up the suction syringe to easily access the BBB.
3. Remove the BBB barrel jack that it uses for power.
4. Grab a USB A to Mini-B cable and use a pair of needle nose pliers to insert the USB plug into the socket on the underside of the BBB's board.
5. WITHOUT PLUGGING IN THE BBB TO YOUR COMPUTER, power on the rest of the robot through the hardware switch. You should see most lights turn on with the notable exception of the BBB, which will get power in the next step
6. Plug in the BBB's usb cable to your computer.
7. SSH in through the IP address: 192.168.7.2

Debugging

We can now begin the debugging process. If we run lsusb, the following line should be present:

Bus 001 Device 007: ID 148f:7601 Ralink Technology, Corp.

If this line is not present, it is likely that we have a power issue. The USB WiFi dongle most likely is not receiving adequate power. Power down the robot and try to correct this issue.

If this line is present, see below:

The next step is to run wicd-curses. Now, ideally we should see that a list of WiFi networks was detected and that it is currently connected to ut-wpa2. This is probably not the case since we were having problems before, but if it is, great! We can hopefully leave the USB shell (see below) and connect through WiFi normally on the next power cycle.

If the status line at the bottom reads, "Not Connected", follow these steps:

Using the arrow keys, navigate to the upper-most ut-wpa2 line and press SHIFT-C. After 30 seconds, the status line should show that we are now connected to ut-wpa2. At this point we should leave the USB shell and reboot. If not, we likely have a WiFi configuration issue and this issue should be addressed by asking someone on the Flowdock.

Leaving the USB shell

1. Follow the clean shutdown procedure (https://github.com/utk-robotics-2016/utk-robotics-2016/wiki/Beaglebone#clean-shutdown)
2. Remove the USB cable using needle-nose pliers.
3. Replace the DC barrel jack.
4. Flip down the suction syringe.

Note that it is not possible to hot-switch from USB power to DC barrel jack power.