Hi all.
Has anybody encountered any VERY small motors that can be controlled directly from an arduino without an H-Bridge, motor shield, or similar?
I think the max current on a pin is 40-50 mA (please correct me if I'm wrong)
I know some small pager motors draw that or less, but was wondering if there was something a little bigger that the robot community uses for small robot projects.
thanks
Something else you want to be careful of,
motors, as well as any other coil based devices, produce back emf when stopped/reversed. If you don’t have diodes in place you will let the magic smoke out of your microcontroller. I would, however, imagine that any small robots that use motors still use some kind of h-bridge. With an L293 only costing about $1, where is your problem with using one?
no problem with using
no problem with using them…it was more of a “keep it simple” thing.
can I use a mosfet instead of an h bridge? (I’m more familiar with how mosfets work)
Transistors are transistors…
Mosfet, fine, but when I think “mosfet” I think T-220 case, 40 amps and a big heat sink. At 40-60mA, you could make an H-bridge (or even just a simple on/off) with tiny little SMD 2n3904’s and 2n3906’s (or really, whatever “general purpose” transistors are handy. I think they are maybe a penny a piece on ebay. Maybe a buck or two if you are only buying 10 or so.
thats all I need to hear.
thats all I need to hear. L293D it is!
the D is “dual” right? (so I only need one for two motors)…correct?
The D is not dual, its diodes
The “D” in L293D is for “diodes”. It is these diodes that will help prevent the EMF feedback that everyone mentioned above.
