It seems you need to isolate the problem area - batteries/motors/driver/PIC
etc.
Can you measure the battery and motor currents & figure out if the motors
are being driven to the same extent (nearly) as when then are connected
directly to the battery - or is the current being bled away elsewhere? - If
an alternative path is draining the batteries to the extent you describe,
the battery lifetime must be very much reduced & there may even be smoke!

Can you lash up a trial using separate supplies for the PIC & the motors?
Just to be 100% sure that the motor hash is not resetting/upsetting the
PIC. Inadequate bypassing on the power supply is the cause of many problems
brought  up on this list.

The Suggestion re the saturation voltage of the drivers had merit also -
can you hard wire the driver chips ON and then try the beast without the
PIC altogether?


Richard P




Hi,
I posted this under EE, but then found a big discussion from
12/2000 about the tamiya twin motor drives.  I still have the same
question, the FA-130 motors are rated 3v@800ma stalled.
snip....................

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