Something's cutting out on the high current spikes I think - old batteries? Not enough
decoupling to 5V supply? Stalling the motor will push the current up, this is triggering
the issue.
Thanks for the inputs, please see attached circuit diagram( pardon me for the handwriting, i tried using frizing but could not find the components that I need)
Hi, have you got the gnd of the motor batteries connected to the gnd of the arduino batteries?
If not then the control outputs, 6 7 8 9 will have go current return path, and so any line that is high will use a line that is low to act as current return.