I recently put together the Rover with blue tooth. IT came with an DFRduino IO expansion board which has servos sockets, but looking at the board it looks like i need to supply additional power for the servos as there is a “servo_pwr” screw in socket. How many volts does this need? will the lipo battery that came with the rover bt kit be able to supply enough juice for the servos and for the rover? or will i need the tripple A batteries as well?
Also I have a ultrasound with 3 pins, do i connect that to analog input digital pins?
I have V4 of the io shield. There is a jumper that says “pwr_sel” above the “servo_pwr” screw terminal, do i just pull this off to get it to be powered by the arduino board?
Depending on the version, the I/O shield should have a jumper to switch V to external power (via the screw terminals) or onboard. So long as the servo is not too big and there is not too much resistive torque (which would cause the current to spike), the Arduino should be able to provide enough current from the 5V pin to power a servo. You can use the LiPo battery, though you have the option of using both the LiPo (connected to the DFRobotShop Rover PCB) and the 4xAA battery pack (connected to the I/O shield and used for powering the servos and sensors separately). A servo takes between 4.8V and 6V, and most sensors operate at 5V.
For the ultrasonic sensor, you need to read the specifications - if the pins are GND -> V -> Signal (analog) then you can certainly connect it to an analog pin.
Having the jumper on should allow you to power the 5V line from the 5V output (however, wit hthe newest version of the board, it may be reversed, so the easy way to check is to light up an LED or test it with a small servo).
