Control a continuous servo

Place the Uno beside the full size breadboard. Keep USB and the separate servo power supply disconnected while wiring. This view is interactive: drag to turn it, and scroll to zoom. The animation will guide you through each connection. Connect ground on the Uno to the upper negative rail at contact five. Later, both negative rails will share this ground reference. Keep the positive rail for servo power separate from the Uno five volt pin. This is a continuous rotation servo. It controls speed and direction, rather than moving to an exact angle. Check its cable colours: brown or black is ground, red is power, and orange or yellow is the control signal. Connect the servo ground lead to the lower negative rail at contact forty two. Connect the red power lead to the lower positive rail at contact forty one. Male to male jumpers fit into the female sockets on the servo cable. Join the upper and lower negative rails at contact thirty eight. This gives the Uno and servo a common ground. A separate regulated five volt servo supply connects to the lower positive and negative rails at contact forty nine. Leave that supply off for now. Connect digital pin nine on the Uno to the servo signal socket. The sketch uses pulses around fifteen hundred microseconds: the neutral pulse stops rotation, and pulses on either side change speed and direction. Your servo may need a small neutral adjustment. Check your wiring, then connect the square USB plug to the Uno and the other end to your computer. Keep the servo supply off while uploading the program below. Open the App, check that it is ready, then power the unloaded servo from its separate supply. Start with a modest positive speed and hold Run. Watch the horn rotate. Release Run to stop. A negative speed turns it the other way. The picture follows the commanded speed; a continuous servo does not report its exact angle.

Place the Uno beside the full size breadboard. Keep USB and the separate servo power supply disconnected while wiring. This view is interactive: drag to turn it, and scroll to zoom. The animation will guide you through each connection.

Connect ground on the Uno to the upper negative rail at contact five. Later, both negative rails will share this ground reference. Keep the positive rail for servo power separate from the Uno five volt pin.

This is a continuous rotation servo. It controls speed and direction, rather than moving to an exact angle. Check its cable colours: brown or black is ground, red is power, and orange or yellow is the control signal.

Connect the servo ground lead to the lower negative rail at contact forty two. Connect the red power lead to the lower positive rail at contact forty one. Male to male jumpers fit into the female sockets on the servo cable.

Join the upper and lower negative rails at contact thirty eight. This gives the Uno and servo a common ground. A separate regulated five volt servo supply connects to the lower positive and negative rails at contact forty nine. Leave that supply off for now.

Connect digital pin nine on the Uno to the servo signal socket. The sketch uses pulses around fifteen hundred microseconds: the neutral pulse stops rotation, and pulses on either side change speed and direction. Your servo may need a small neutral adjustment.

Check your wiring, then connect the square USB plug to the Uno and the other end to your computer. Keep the servo supply off while uploading the program below. Open the App, check that it is ready, then power the unloaded servo from its separate supply.

Start with a modest positive speed and hold Run. Watch the horn rotate. Release Run to stop. A negative speed turns it the other way. The picture follows the commanded speed; a continuous servo does not report its exact angle.