28BYJ-48 stepper with Teensy 4.1

Wiring for the 28BYJ-48 stepper + ULN2003 driver on the Teensy 4.1 (MIMXRT1062DVJ6B, 3.3 V logic), chosen with the same pin rules BoardPilot uses: default buses first, and no pins that are used for flash, USB, the debugger or booting.

Wiring

28BYJ-48 stepper pin	Role	Teensy 4.1 pin	Notes
IN1	Input to the part	2 (GPIO_EMC_04)
IN2	Input to the part	3 (GPIO_EMC_05)
IN3	Input to the part	4 (GPIO_EMC_06)
IN4	Input to the part	5 (GPIO_EMC_08)
-	Ground	G
+	Power	3V	Motor supply 5 V: use 3V (about 240 mA)

Check before you power it on

Supply: 3.3 V from the 3V pin.
Motors, servos, relays and LED strips can draw more current than the Teensy 4.1’s pins or USB can give. Power them separately and connect the grounds together.

Test code (Arduino)

// Library: Stepper (built in)
#include <Stepper.h>

// 2048 steps per turn; note the IN1, IN3, IN2, IN4 order for this motor
Stepper motor(2048, 2, 4, 3, 5);

void setup() {
  motor.setSpeed(10);  // rpm
}

void loop() {
  motor.step(2048);   // one turn
  delay(500);
  motor.step(-2048);  // and back
  delay(500);
}

Arduino board: teensy:avr:teensy41. Press the white program button once if the upload waits for the board.

Questions

Which Teensy 4.1 pins do I use for the 28BYJ-48 stepper?

IN1 → 2 (GPIO_EMC_04), IN2 → 3 (GPIO_EMC_05), IN3 → 4 (GPIO_EMC_06), IN4 → 5 (GPIO_EMC_08), - → G, + → 3V.

Does the 28BYJ-48 stepper work with the Teensy 4.1 at 3.3 V?

Yes: the 28BYJ-48 stepper runs at 5 V and the Teensy 4.1 uses 3.3 V signals, so no level shifting is needed.

BoardPilot checks this wiring in 3D as you build it, and finds crossed or missing wires on the real board.

Download BoardPilot

Full Teensy 4.1 pinout · 28BYJ-48 stepper + ULN2003 driver: all pins and data

The 28BYJ-48 stepper on other boards

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