We are surrounded by stepper motors without even realizing it, as they are used in so many everyday items, including window blinds, 3D printers, DVD players, security cameras, and CNC machines. We're a lot closer to stepper motors than you think.
Stepper motors fall somewhere between a conventional DC motor and a servo motor. They can rotate continuously like DC motors and be positioned precisely (in discrete steps) like servo motors.
If you're just getting started with stepper motors, the 28BYJ-48 is a great choice. They typically come with a ULN2003-based driver board, making them very simple to use.
The 28BYJ-48 Stepper Motor
The 28BYJ-48 is a 5-wire unipolar stepper motor that runs on 5V. It's perfect for projects that require precise positioning, such as opening and closing a vent.
Because the motor does not use contact brushes, it has a relatively precise movement and is quite reliable.
Despite its small size, the motor delivers a decent torque of 34.3 mN.m at a speed of around 15 RPM. It provides good torque even at a stand still and maintains it as long as the motor receives power.
The only drawback is that it is somewhat power-hungry and consumes energy even when it is stationary.
Pinout
The 28BYJ-48 stepper motor has five wires.
The 28BYJ-48 has two coils, each of which has a center tap. These two center taps are connected internally and brought out as the 5th wire (red wire).
The red wire is always pulled HIGH, so when the other lead is pulled LOW, the phase is energized.
The stepper motor rotates only when the phases are energized in a logical sequence known as a step sequence.
Gear reduction ratio
According to the data sheet, when the 28BYJ-48 motor is operated in full-step mode, each step corresponds to a rotation of 11.25°. This means there are 32 steps per revolution (360°/11.25° = 32).
In addition, the motor features a 1/64 reduction gear set (actually, it is 1/63.68395, but 1/64 is a good enough approximation for most purposes).
This means that there are in fact 2038 steps (32*63.68395 steps per revolution = 2037.8864 approximately 2038 steps).
Power Consumption
The 28BYJ-48 typically draws about 240 mA.
Because the motor consumes a significant amount of power, it is preferable to power it directly from an external 5V power supply rather than from the Arduino.
It is worth noting that the motor consumes power even when it is at rest in order to maintain its position.
The ULN2003 Driver Board
Because the 28BYJ-48 stepper motor consumes a significant amount of power, it cannot be controlled directly by a microcontroller such as Arduino. To control the motor, a driver IC such as the ULN2003 is required; Therefore, this motor typically comes with a ULN2003-based driver board.
The ULN2003, known for its high current and high voltage capability, provides a higher current gain than a single transistor and allows a microcontroller's low voltage low current output to drive a high current stepper motor.
The ULN2003 consists of an array of seven Darlington transistor pairs, each of which can drive a load of up to 500mA and 50V. This board utilizes four of the seven pairs.
Additionally, there is a Molex connector that is compatible with the connector on the motor, allowing you to plug the motor directly into it.
The board includes four LEDs that indicate activity on the four control input lines. They provide a good visual indication while stepping.
There is an ON/OFF jumper on the board for disabling the stepper motor if needed.
Connect the driver board's IN1, IN2, IN3, and IN4 to Arduino digital pins 8, 9, 10, and 11, respectively. Then connect the stepper motor to the ULN2003 driver.
We are surrounded by stepper motors without even realizing it, as they are used in so many everyday items, including window blinds, 3D printers, DVD players, security cameras, and CNC machines. We're a lot closer to stepper motors than you think.
Stepper motors fall somewhere between a conventional DC motor and a servo motor. They can rotate continuously like DC motors and be positioned precisely (in discrete steps) like servo motors.
If you're just getting started with stepper motors, the 28BYJ-48 is a great choice. They typically come with a ULN2003-based driver board, making them very simple to use.
The 28BYJ-48 Stepper Motor
The 28BYJ-48 is a 5-wire unipolar stepper motor that runs on 5V. It's perfect for projects that require precise positioning, such as opening and closing a vent.
Because the motor does not use contact brushes, it has a relatively precise movement and is quite reliable.
Despite its small size, the motor delivers a decent torque of 34.3 mN.m at a speed of around 15 RPM. It provides good torque even at a stand still and maintains it as long as the motor receives power.
The only drawback is that it is somewhat power-hungry and consumes energy even when it is stationary.
Pinout
The 28BYJ-48 stepper motor has five wires.
The 28BYJ-48 has two coils, each of which has a center tap. These two center taps are connected internally and brought out as the 5th wire (red wire).
The red wire is always pulled HIGH, so when the other lead is pulled LOW, the phase is energized.
The stepper motor rotates only when the phases are energized in a logical sequence known as a step sequence.
Gear reduction ratio
According to the data sheet, when the 28BYJ-48 motor is operated in full-step mode, each step corresponds to a rotation of 11.25°. This means there are 32 steps per revolution (360°/11.25° = 32).
In addition, the motor features a 1/64 reduction gear set (actually, it is 1/63.68395, but 1/64 is a good enough approximation for most purposes).
This means that there are in fact 2038 steps (32*63.68395 steps per revolution = 2037.8864 approximately 2038 steps).
Power Consumption
The 28BYJ-48 typically draws about 240 mA.
Because the motor consumes a significant amount of power, it is preferable to power it directly from an external 5V power supply rather than from the Arduino.
It is worth noting that the motor consumes power even when it is at rest in order to maintain its position.
The ULN2003 Driver Board
Because the 28BYJ-48 stepper motor consumes a significant amount of power, it cannot be controlled directly by a microcontroller such as Arduino. To control the motor, a driver IC such as the ULN2003 is required; Therefore, this motor typically comes with a ULN2003-based driver board.
The ULN2003, known for its high current and high voltage capability, provides a higher current gain than a single transistor and allows a microcontroller's low voltage low current output to drive a high current stepper motor.
The ULN2003 consists of an array of seven Darlington transistor pairs, each of which can drive a load of up to 500mA and 50V. This board utilizes four of the seven pairs.
Additionally, there is a Molex connector that is compatible with the connector on the motor, allowing you to plug the motor directly into it.
The board includes four LEDs that indicate activity on the four control input lines. They provide a good visual indication while stepping.
There is an ON/OFF jumper on the board for disabling the stepper motor if needed.
Connect the driver board's IN1, IN2, IN3, and IN4 to Arduino digital pins 8, 9, 10, and 11, respectively. Then connect the stepper motor to the ULN2003 driver.
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