Control a servo with distance

We’re making a distance-controlled servo. Move an object closer to slow it down, or further away to speed it up. This unloaded demonstration uses U S B power through the Uno. Leave U S B disconnected while wiring. Connect five volts from the Uno to the upper positive rail, and ground to the upper negative rail. These shared connections will supply both the sensor and the servo. This ultrasonic sensor measures distance using its two silver transducers. Face them towards the object you want to detect, with the four header pins accessible for the jumper wires. Connect the sensor’s power pin to the upper positive rail, then its ground pin to the upper negative rail. Red carries five volts; black provides the return to ground. Connect digital pin seven to trigger, then digital pin six to echo. The Uno sends a brief trigger pulse and times the returning echo to work out the distance. This servo turns continuously. Our program controls its speed and direction, rather than choosing an angle. Keep the horn clear so the motor can turn freely during this demonstration. Connect the servo’s red power lead to the upper positive rail. Connect its brown or black ground lead to the lower negative rail. The remaining lead carries the control signal. Join the upper and lower negative rails with a black jumper. That completes the servo’s return path to the Uno, so the sensor, servo and controller share the same ground. Connect digital pin nine to the servo’s signal lead. The Servo library sends timed pulses: around fifteen hundred microseconds stops the motor, while shorter or longer pulses change its speed and direction. Check the wiring, then connect U S B to the Uno and upload the program below. Keep the servo unloaded. If the board resets or the motor struggles, unplug U S B and stop the test. Choose distance sensor mode and hold Run. Bring an object closer to slow the servo; at fifteen centimetres it stops. Move away to speed up again. Release Run to stop the motor.

We’re making a distance-controlled servo. Move an object closer to slow it down, or further away to speed it up. This unloaded demonstration uses U S B power through the Uno. Leave U S B disconnected while wiring.

Connect five volts from the Uno to the upper positive rail, and ground to the upper negative rail. These shared connections will supply both the sensor and the servo.

This ultrasonic sensor measures distance using its two silver transducers. Face them towards the object you want to detect, with the four header pins accessible for the jumper wires.

Connect the sensor’s power pin to the upper positive rail, then its ground pin to the upper negative rail. Red carries five volts; black provides the return to ground.

Connect digital pin seven to trigger, then digital pin six to echo. The Uno sends a brief trigger pulse and times the returning echo to work out the distance.

This servo turns continuously. Our program controls its speed and direction, rather than choosing an angle. Keep the horn clear so the motor can turn freely during this demonstration.

Connect the servo’s red power lead to the upper positive rail. Connect its brown or black ground lead to the lower negative rail. The remaining lead carries the control signal.

Join the upper and lower negative rails with a black jumper. That completes the servo’s return path to the Uno, so the sensor, servo and controller share the same ground.

Connect digital pin nine to the servo’s signal lead. The Servo library sends timed pulses: around fifteen hundred microseconds stops the motor, while shorter or longer pulses change its speed and direction.

Check the wiring, then connect U S B to the Uno and upload the program below. Keep the servo unloaded. If the board resets or the motor struggles, unplug U S B and stop the test.

Choose distance sensor mode and hold Run. Bring an object closer to slow the servo; at fifteen centimetres it stops. Move away to speed up again. Release Run to stop the motor.