Servos, solenoids and actuators lesson plan
Everything that moves a thing to a place: servo pulses measured and calibrated, big servos and their supply, easing curves, solenoids with a flyback diode, linear actuators, vibration motors, and an animatronic face on a PCA9685.
Objectives and materials
By the end, students can
- Pulse widths you can predict, a window you can calibrate, a big servo’s supply, and motion that eases.
- A solenoid and the diode that saves its MOSFET, and a linear actuator placed by the clock.
- A coin vibration motor: its start voltage, a kick-start, and patterns that carry meaning.
- An animatronic face on a PCA9685 with moods, blinks, glances and a jaw that talks.
Materials for the whole unit
- Arduino Uno R3
- Battery: AA, coin cell, LiPo
- Bench power supply
- Diode
- Full-size breadboard
- Hobby servo x 4
- Linear actuator, 12 V
- MOSFET
- Motor driver module, L298N
- Potentiometer
- Pushbutton
- Resistor
- Servo driver, PCA9685 16-channel
- Servo, MG996R metal gear
- Slide potentiometer
- Solenoid
- Transistor (NPN or PNP)
- Vibration motor
Every part is already on the simulator’s bench, so there is nothing to buy or hand out. The counts are the most any one lesson uses, if you build it on real breadboards too.
Servos for real
Pulse widths you can predict, a window you can calibrate, a big servo’s supply, and motion that eases.
| Lesson | Time | What students do |
|---|---|---|
| Servo pulses: measure, predict, calibrateSend a servo any pulse width you like from the Serial Monitor, predict the angle before you press Enter, read the current it draws while it moves, and calibrate for a servo with a different window. | 50 min |
|
| Big servos: the amps are the hard partAn MG996R metal-gear servo on its own 6 V pack. The same pulses as an SG90, but a supply that has to give amps, a speed that falls with the voltage, and a servo that gives up below 4 V. | 50 min |
|
| Easing: motion that looks aliveThe same servo move three ways: linear, smoothstep and ease-out-back. Predict where each curve puts the horn at a quarter of the time, then make the move slower. | 50 min |
|
Materials
- Arduino Uno R3
- Battery: AA, coin cell, LiPo
- Bench power supply
- Full-size breadboard
- Hobby servo
- Potentiometer
- Pushbutton
- Resistor
- Servo, MG996R metal gear
- Slide potentiometer
Check for understanding
Each student finishes "Easing: motion that looks alive" on their own, without opening the hints. The simulator checks 6 of its 6 steps as they go.
Then ask each one to explain, in a sentence or two, the last thing it asked of them: "Why the servo still limits you".
Push and pull
A solenoid and the diode that saves its MOSFET, and a linear actuator placed by the clock.
| Lesson | Time | What students do |
|---|---|---|
| Solenoids and the flyback diodeA 12 V push-pull solenoid on a logic-level MOSFET. Predict the coil current from Ohm’s law, watch the diode carry the kick when the MOSFET lets go, and tap faster. | 50 min |
|
| Linear actuators and end stopsA 12 V linear actuator on an L298N. Drive it to its end switches, place it by the clock alone, and see dead reckoning come up short the moment the load changes. | 50 min |
|
Materials
- Arduino Uno R3
- Bench power supply
- Diode
- Full-size breadboard
- Linear actuator, 12 V
- MOSFET
- Motor driver module, L298N
- Solenoid
Check for understanding
Each student finishes "Linear actuators and end stops" on their own, without opening the hints. The simulator checks 6 of its 6 steps as they go.
Then ask each one to explain, in a sentence or two, the last thing it asked of them: "Feedback, current and fuses".
Feel it
A coin vibration motor: its start voltage, a kick-start, and patterns that carry meaning.
| Lesson | Time | What students do |
|---|---|---|
| Vibration motors: hapticsA coin vibration motor on a 2N2222. Predict its current, find the duty where it will not start, kick-start it, and play and tune haptic patterns. | 50 min |
|
Materials
- Arduino Uno R3
- Diode
- Pushbutton
- Resistor
- Transistor (NPN or PNP)
- Vibration motor
Check for understanding
Each student finishes "Vibration motors: haptics" on their own, without opening the hints. The simulator checks 6 of its 6 steps as they go.
Then ask each one to explain, in a sentence or two, the last thing it asked of them: "Tune the tap".
Boss build
An animatronic face on a PCA9685 with moods, blinks, glances and a jaw that talks.
| Lesson | Time | What students do |
|---|---|---|
| Boss: an animatronic faceEyes, eyelids, brows and a jaw on four servos through a PCA9685. Moods from a table, blinks and glances on millis(), a talk command, and a face you make your own. | 60 min |
|
Materials
- Arduino Uno R3
- Hobby servo x 4
- Pushbutton
- Servo driver, PCA9685 16-channel
Check for understanding
Each student finishes "Boss: an animatronic face" on their own, without opening the hints. The simulator checks 7 of its 7 steps as they go.
Then ask each one to explain, in a sentence or two, the last thing it asked of them: "Make it yours".
Teach this unit as a class
Start a class from this course and its 7 lessons are assigned in one go, in order. Students join with a six-character code or printed login cards, and each one’s work comes back to you.
The class tools are free for 30 days for one class of up to 20 students, with no card. The lessons themselves are free either way.