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Resolved Resolved by DJ Sures!

Ezb V4 Disconnect Question

Good Morning,

Last night i was playing with my robot, and i think that it went out of wifi range. I could not stop my robot and it ran into a shelf and broke one of my wife's coffee mugs. I know on the version 3 board if you went out of bluetooth range the board stopped everything. On this version 4 board it is supposed to do the same thing?

Thoughts?

(P.S. My wife would love to know also!)

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Synthiam
#1  
What motor controller are you using?... The sabertooth continues based on the last command given to it (in serial mode, anyway).. Not sure if there is a setting to change that... Also, are you sure it was out of wifi range or something else (no offence, maybe bad coding and this has happened to me so that's why I am asking) that might of happened to cause a disconnect?.. I use to get disconnects all the time until I upgraded my crappy router...
PRO
Synthiam
#2  
@WayneA the EZ-B v4 would stop servos and float all I/o pins after disconnection. This is not possible with the EZ-B v4. If you are building a large robot capable of seeking and destroying coffee mugs, it is a good idea to install a safety switch.:)

Large robots should have a safety switch for more reasons than your wife's unfortunate coffee mug incident. Specifically when there are children or if the robot is being used in public.

Generally, wifi is very stable and there shouldn't be a problem. On the rare occurrence of an issue, the safety switch will come in handy.
United Kingdom
#4  
If the motor controller remains powered after the EZ-B disconnects and floats all IO pins you could always wire in a relay to power the motor controller only if the EZ-B is connected.

The EZ-B V3 would drop all IO pins to ground on disconnect, which was useful as you could do things like this...


I presume the V4 works in the same way.

You can take this to the next level and wire in a TIP122 based switching circuit which would energise a relay which then enables power to the motor controller.
User-inserted image


This should then act as a failsafe should disconnection occur, basically put it will kill the power to the drivetrain so the robot should stop on the spot and therefore avoid any demolition, maiming or breaking of coffee cups or people.
#5  
Thank You all for your help and feedback. My wife is now happy!
#6  
Yup seen this problem myself. EZB4 Controlling robo claw motor controller (serial mode control) , 2 wheel chair motors, .... wifi disconnect, could not re-connect, robot pushed couch with 3 children on it till it ran into fireplace. I had to yank a battery wire off. No injuries. Lesson learned!

Chris