User Manual

Mini Maestro 12 power pins.
Mini Maestro 18 power pins.
Mini Maestro 24 power pins.
The processor and the servos can have separate power
supplies.
Processor power must come either from USB or from
an external 5–16V power supply connected to the VIN
and GND inputs on the left side of the board. It is safe to
have an external power supply connected at the same
time that USB is connected; in that case the processor
will be powered from the external supply. Note that if the
external supply falls below 5 V, correct operation is not
guaranteed, even if USB is also connected.
Servo power connections are provided in the lower right
corner of the Mini Maestro board. On the Mini Maestro
18 and 24, you can make servo power connections via a
2-pin terminal block or a 2-pin 0.1″ header; the Mini
Maestro 12 only has a 2-pin 0.1″ header for connecting
servo power. Servo power is passed directly to the
servos without going through a regulator, so the only
restrictions on your servo power supply are that it must
be within the operating range of your servos and provide
enough current for your application. Please consult the
datasheets for your servos to determine an appropriate
servo power source, and note that a ballpark figure for
the current draw of an average straining servo is 1 A.
You can power the Maestro’s processor and servos from
a single power supply by connecting the positive power
line to both VIN and the servo power ports (only one
ground connection is needed because all ground pins on
the board are connected). The recommended way to do
this is to connect your power supply to the dedicated
servo power pins in the corner of the board and use the
included blue shorting block to connect the pins labeled
“VSRV=VIN”.
The 5V (out) power output allows you to power your own
5V devices from the 100mA on-board regulator or directly from USB. The on-board regulator is used
whenever VIN is powered; in this case, since the Maestro requires 50 mA, there is about 50 mA
available to power other devices.
Pololu Maestro Servo Controller User’s Guide © 2001–2017 Pololu Corporation
1. Overview Page 15 of 99