Vibration Motor

What it is

A coin vibration motor and the circuit that drives it. The motor is 10 mm across, lies flat on the board on its own tape, and spins an off-centre weight at about fifteen thousand rpm. The rest of the board is its driver: a MOSFET that switches it, a 10 kΩ that keeps it off when nothing drives SIGNAL, a 3.3 V regulator that feeds it, a diode that takes the kick when it stops, and an LED that lights while it is driven.

SIGNAL HIGH closes the MOSFET and the motor runs; LOW opens it and the motor coasts to a stop. analogWrite sets the strength, down to about 178 of 255 from rest; below that, start it at full power and then drop. The motor's current, about 54 mA running and up to 120 mA starting, never passes through your board's pin, which only drives the MOSFET's gate.

The page this replaces left the regulator out, and suggested a separate supply and a large capacitor for the motor. On this board the motor already has its own supply, the regulator, and VCC can be 5V or 3V3 on every board.

VCC feeds the regulator, and nothing else

5V on VCC beside a 3.3 V board is safe here: VCC reaches only the regulator and its capacitor, and SIGNAL reaches only the MOSFET's gate. The motor is a 3.0 V part rated for 2.7 to 3.3 V, and the regulator holds it at 3.3 V. VCC on 3V3 gives it about 3.3 V too, measured on a board, so on a battery with no 5 V pin, or whenever 3V3 is nearer, use 3V3.

Which pin is which

Parts up, header at the bottom, reading left to right:

The back prints TK30 VIBRATION MOTOR and, along the bottom, VIBRATES WHEN THE INPUT IS HIGH, STOPS WHEN IT'S LOW, but no pin names. Turned over, the square pad is on the right, and it is still GND.

Wiring, in three lines

1. GND to your board's GND.
2. VCC to 5V: an Uno's 5V, the 5V pin of an ESP32 or ESP32-S3 board on USB, or a Pico's VBUS. 3V3 works as well: the motor gets the same 3.3 V.
3. SIGNAL to a PWM pin: D9 on an Uno, GPIO 4 on an ESP32 or ESP32-S3, GP15 on a Pico.

Leave NC unconnected.

Example

// A PWM pin. Uno: 9. ESP32: 4. ESP32-S3: 4. Pico: 15.
const int MOTOR_PIN = 9;
const int KICK_MS = 50;   // full power first, so low levels start

void buzz(int level, int ms) {
  analogWrite(MOTOR_PIN, 255);      // kick: sure to start
  delay(KICK_MS);
  analogWrite(MOTOR_PIN, level);    // then the strength you want
  delay(ms);
  analogWrite(MOTOR_PIN, 0);
}

void setup() {
  pinMode(MOTOR_PIN, OUTPUT);
}

void loop() {
  buzz(255, 300);   // strong
  delay(700);
  buzz(150, 300);   // gentler
  delay(700);
}

import time
from machine import Pin, PWM

# A PWM pin. ESP32: 4. ESP32-S3: 4. Pico: 15.
motor = PWM(Pin(4), freq=1000)
motor.duty_u16(0)
KICK_MS = 50              # full power first, so low levels start

def buzz(level, ms):
    motor.duty_u16(65535)             # kick: sure to start
    time.sleep_ms(KICK_MS)
    motor.duty_u16(level * 257)       # then the strength you want
    time.sleep_ms(ms)
    motor.duty_u16(0)

while True:
    buzz(255, 300)        # strong
    time.sleep_ms(700)
    buzz(150, 300)        # gentler
    time.sleep_ms(700)

Where to start

The handbook below is ten short articles, each with a working figure. The first buzz is the whole build in three wires and a few lines, and why VCC can be 5V is the one page that explains the wiring.

For strength, read strength is a duty cycle and a kick to start. For haptic feedback on a button, patterns you can feel. If it will not buzz, when it does not buzz.