Motor Driver

A motor driver is an electronic device or circuit that is used to control the operation of
motors. It acts as an interface between the microcontroller (or another control system) and
the motor itself, allowing the low-power control signals from the microcontroller to control
the higher power required to drive the motor. Motor drivers typically manage the direction,
speed, and sometimes the torque of the motor.
Key Functions of a Motor Driver:
 Amplification: It amplifies the low-current control signals from a microcontroller to
higher currents required by the motor.
 Direction Control: Allows the motor to spin in either direction by controlling the
polarity of the voltage applied to the motor.
 Speed Control: Often uses Pulse Width Modulation (PWM) to control the speed of
the motor.
 Protection: Protects the motor and the control circuit from damage due to
overcurrent, overheating, or other faults.

Types of Motor Driver-

1. H-Bridge Motor Drivers
2. MOSFET-Based Motor Drivers
3. Stepper Motor Drivers
4. Brushless DC Motor (BLDC) Driver

For our self Balancing bot, we choose stepper Motor Drivers because of its stability,
microstepping, precision and accuracy, torque control, low speed performance etc…

Stepper Driver
Stepper Motor Drivers Overview
A stepper motor driver is a circuit that controls the operation of a stepper motor, managing
the current and voltage supplied to the motor's coils to ensure precise movement. The
driver translates low-power control signals (from a microcontroller, for example) into the
higher power required by the motor.
Key Features of Stepper Motor Drivers:
 Micro stepping: Allows for finer control of the motor's position by dividing each full
step into smaller steps, resulting in smoother motion and higher resolution.
 Current Control: Regulates the current flowing through the motor coils, helping
manage heat and power efficiency.
 Direction and Step Control: The driver typically has inputs for step and direction;
each pulse on the step pin moves the motor by one step, and the direction pin
controls the direction of rotation.
 Enable/Disable Function: Some drivers have an enable pin to activate or deactivate
the motor, allowing it to hold its position or be powered down to save energy.

Popular Stepper Motor Drivers for Your Project

Here are some stepper motor drivers that would work well with a 1.8-degree
stepper motor:
1. A4988

o Current Capacity: Up to 2A per coil with proper cooling.

o Micro stepping: Up to 1/16th micro stepping.
o Supply Voltage: 8V to 35V.
o Features: Adjustable current control, over-temperature shutdown,
crossover-current protection.
o Use Case: Suitable for small to medium-sized stepper motors, often
used in 3D printers and small CNC machines.
2. DRV8825

o Current Capacity: Up to 2.5A per coil with proper cooling.

o Micro stepping: Up to 1/32nd micro stepping.
o Supply Voltage: 8.2V to 45V.
o Features: Higher current capacity than the A4988, similar features with
improved performance.
o Use Case: A good choice for more demanding applications or if you need finer
micro stepping resolution.
3. TB6600

o Current Capacity: Up to 4.5A per coil.

o Micro stepping: Up to 1/32nd micro stepping.
o Supply Voltage: 9V to 42V.
o Features: Higher current capacity, ideal for larger stepper motors.
o Use Case: Suitable for more powerful stepper motors in CNC machines, larger
3D printers, or robotics.
 4. TMC2208/TMC2209

o Current Capacity: TMC2208 up to 1.4A per coil (up to 2A peak); TMC2209 up to

2A per coil (up to 2.8A peak).
o Micro stepping: Up to 1/256th micro stepping.
o Supply Voltage: 4.75V to 36V.
o Features: Ultra-quiet operation, stall detection, advanced current control,
Stealth Chop and Spread Cycle modes for smooth motion.
o Use Case: Ideal for applications where noise and smoothness are critical, such
as 3D printers and precision robotics.

We used TB6600 stepper motor driver for our self balancing bot, because of high current
capability, smooth microstepping, stable operation and many more features which
collectively contribute to better performance in maintaining the balance and control of the
bot.

Integration with AccelStepper Library

  Driver Selection: The AccelStepper library supports various driver types, including
those listed above. When using the library, you'll need to initialize the stepper motor
with the correct driver type.
 Dynamic Control: With drivers like the DRV8825 or TMC series, you can dynamically
adjust speed and acceleration using the library, allowing for more flexible motion
control in your project.

Accelstepper commands:
 .run():
Step the motor(once per loop)
If a step is required based on the current speed and time since the last step
it steps the motor as per maxspeed and acceleration
 .runspeed():
Steps the motor as per constant speed
 Set current position():
It resets the current position to zero
 Set maxspeed():
Sets the maximum possible speed in steps per second
(for example, for 400 microstep 200 max speed)
 Set acceleration
Set acceleration in steps per second 2
 Moveto():
Sets the target position if the motor is at current position zero and also
recalculates the speed for the next step
i.e., if x steps were already taken then
steps taken=steps required-x;
 Move():
Sets the target position
 Stop():
Stops the motor

Motors
A motor is a device that converts electrical energy into mechanical energy through
rotational movement. It operates by creating a magnetic field that interacts with the
motor's components to produce motion. Motors are widely used in various applications,
from powering appliances and vehicles to driving industrial machinery.
Key function of motors:
 Converting Energy: Transforms electrical energy into mechanical energy,
enabling movement.
 Generating Motion: Produces rotational motion , which drives mechanical
components.
 Driving Loads: Powers machinery, vehicles, and devices by providing the
necessary force to move or operate them.
 Controlling Speed and Direction: Allows precise control over the speed and
direction of the rotational movement.
 Providing Torque: Delivers the rotational force required to perform work or
overcome resistance.

Types of motors
 DC motors
 Stepper motors
 Servo motors
 Brushless DC motors(BLDC)
 Universal motors

1.Direct Current (DC) Motors

Operation:
Convert electrical energy into mechanical motion using a magnetic field created by direct
current.
Components: Rotor (armature), stator, commutator, and brushes.
Characteristics:
  Speed Control: Speed is adjusted by varying the voltage.
 Torque Control: Directly proportional to current.
 Applications: Used in applications requiring variable speed, such as toys, fans, and
small appliances.

2. Stepper Motors

Operation:
Move in discrete steps, each step corresponding to a fixed angle.
Components: Rotor with permanent magnets and stator windings.
Characteristics:
 Precision: High precision with discrete movement.
 Microstepping: Allows finer control by subdividing each step into smaller increments.
 Applications: Common in 3D printers, CNC machines, and robotics where precise
positioning is required.

3. Servo Motors

Operation:
Provide precise control of angular position using feedback mechanisms like potentiometers
or encoders.
Components: Motor, feedback sensor, and control circuit.
Characteristics:
 Precision Control: High accuracy in position, speed, and torque.
 Built-In Control: Integrated electronics simplify control.
 Applications: Used in robotics, RC vehicles, and industrial automation for accurate
positioning.

5. Brushless DC Motors (BLDC)

Operation:
Use electronic commutation instead of brushes, which reduces friction and wear.
Components: Rotor with permanent magnets and stator windings, controlled by an
electronic speed controller (ESC).
Characteristics:
 Efficiency: Higher efficiency and reliability due to the lack of brushes.
 Longevity: Longer lifespan with fewer moving parts.
 Applications: Suitable for drones, electric vehicles, and high-performance fans.

6. Universal Motors

Operation:
 Can operate on both AC and DC power, similar to brushed DC motors but designed for
versatility.
Components: Similar to DC motors but adapted for AC operation.
Characteristics:
 High Speed: Can achieve high speeds and provide good torque at low speeds.
 Versatility: Operate with both AC and DC supplies.
 Applications: Found in household appliances like vacuum cleaners and power
tools.

Stepper motors are used in our bot , because they provide precise control and
predictable movement, essential for accurate balancing. Their ability to deliver consistent
torque at low speeds and smooth motion through microstepping makes them ideal for
maintaining stability and reliable performance.

Circuit:

Circuit connection of motor and motor driver