[Myro-users] IPRE Fluke Firmware Version

[Jay Summet]

>  A couple of the groups  
> immediately begin experiencing problems with the Scribbler's forward/ 
> motors functions.  The robot would hang on these movement functions,  
> never to return.  This behavior appeared non-deterministic, since even  
> those groups whose robots initially seemed to be functioning correctly  
> eventually encountered the same issue.

This sounds very much like the "low battery causing bluetooth to fail"
problem.  What happens is that a robot has medium to low batteries,
which provide enough voltage to run the fluke and bluetooth radio. The
computer connects successfully, but as soon as the user issues a
movement command (forward, turn, etc) the motors turn on, which take a
lot more current. This extra current draw lowers the voltage, and the
bluetooth radio (and/or fluke) shut down. (once this happens, the robot
keeps doing the last thing it was told, which is typically to move
forward/turn, etc....

The fix: New or re-charged batteries.


>It turns out that her class never upgraded their fluke's  
> firmware and were still running version 2.7.4 (while mine were all set  
> to use 2.7.9).  Both her robots and my own were using version 2.8.1 of  
> the Scribbler firmware.
> 

I can think of no reason why a firmware upgrade would cause the behavior
you have mentioned. We use the latest firmware and although I have seen
a lot of students have the problem you describe, putting in new
batteries has always fixed it.


> After downgrading my fluke's firmware to 2.7.8 (the only available  
> release before this appears to be 2.6.4), my robot started to return  
> from its movement functions without incident.

I suppose it is possible that one firmware somehow taxes the hardware a
bit more than others, requiring a slightly higher voltage, but I must
ask, did you change robots, batteries, or charge batteries while
debugging and/or programming flukes with different firmware versions?

If you can reproduce this problem with fresh batteries Georgia Robotics
may want to swap out your fluke so they can examine it.

Note: The "getBattery()" function call will tell you the current battery
voltage level.

Jay