[Dprglist] another wireless networking issue - headless Raspberry Pi

Clayton Timmons ctimmons at ieee.org
Mon May 14 16:13:46 PDT 2018

RoboRama was great!   So much fun talking with fellow robot enthusiasts and
seeing cool robots in action.

I cobbled together my Raspberry Eye robot right before the contest and ran
into a wireless networking issue.    My robot uses a Raspberry Pi however
it is "headless"  with no onboard keyboard, screen, or buttons of any
type.    It was pre-programmed to connect to my home WiFi and then I would
use a laptop also connected to my home WiFi to sever as the interface to
the robot.   I connect via VNC.

The setup worked great at my house but when I brought the robot to the
Makerspace the problem was obvious.   My robot would try to connect to my
home WiFi which is not available at the Makerspace and being totally
headless there is no easy way to re-program it to do anything different.

I had anticipated this problem and tried one solution but it was not
reliable.   I spoke with Ron Grant and he said - just bring your own access
point.   Thankfully Ron let me use his access point and I was able to get
things running.

I'm seeking the wisdom of the club for solutions to this problem.    Here
are some ideas I have.

1)  Setup Raspberry Pi as an access point -  Then anyone can login to my
robot with correct password.  I saw this as an option but it looked tricky
to setup.

2) Setup Laptop as access point -  I tried this and it worked, sort of.
 Windows 10 was easy to setup as an access point.   It worked but for some
reason was flakey.   Really hard to debug why robot would connect sometimes
and not others to the laptop but reliable connect to my home WiFi.

3) Use Ethernet cable.    I tried to run a cable from robot to hub and
another from laptop to hub.   Hoping I could VNC directly to static IP
address of robot.   This did not work.   I suspect it would work if I
plugged both into a router (not just a hub).   This would give me temporary
remote access via cable rather than wireless.  With cabled remote access I
could re-program the robot to use any available WiFi.   Adafruit sells a
USB to serial interface that is supposed to provide a back door to SSH into
the Raspberry Pi - will have to try that also.

4) add keyboard / screen to robot -   The headless robot is really not a
robust setup since robot is pretty much dead in the water if you can't
connect to it.

5)  Pull microSD card and re-program it.  -   This is what I ended up
doing.   I plugged the microSD card from the robot into a backup Raspberry
Pi with screen and keyboard.   Then I switched the WiFi network name from
my home WiFi to one that was available (Ron's access point).

Any ideas / comments on a solution?


-Clay Timmons-
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