How to Make an Automatic Speed Controller for Electric Bike using Arduino

 

Introduction

Building an automatic speed controller for an electric bike using Arduino offers a cost-effective way to enhance your e-bike's performance and functionality. This comprehensive guide will walk you through the process of creating a sophisticated speed controller system, from component selection to final testing and troubleshooting.

Required Components

Hardware Components

Component
Specification
Quantity
Purpose
Arduino Nano/Uno
ATmega328P
1
Main controller
Hall Effect Sensor
3144/3144E
1
Speed sensing
MOSFET
IRF3205
1
Motor control
LCD Display
16x2 I2C
1
User interface
Voltage Regulator
LM7805
1
5V power supply
Current Sensor
ACS712
1
Motor current monitoring
Throttle
Hall Effect
1
Speed control input
Push Buttons
Momentary
2
User input
Heat Sink
TO-220
2
MOSFET cooling
PCB
Custom
1
Component mounting

Additional Materials

Material
Specification
Purpose
Wire
18-22 AWG
Connections
Heat Shrink
Various sizes
Wire insulation
Project Box
IP65 rated
Housing
Mounting Hardware
M3/M4 screws
Assembly
Thermal Paste
Silicon-based
Heat transfer

Circuit Design

Power Management

Component
Input
Output
Maximum Current
Battery Input
24-48V
-
30A
Voltage Regulator
24-48V
5V
1A
Logic Level
5V
3.3V/5V
200mA
Motor Control
24-48V
PWM
30A

Pin Connections

Arduino Pin
Connection
Purpose
D2
Hall Sensor
Speed sensing
D3
PWM Output
Motor control
A0
Throttle
Speed input
A1
Current Sensor
Current monitoring
A4/A5
LCD (I2C)
Display interface
D7/D8
Push Buttons
User interface

Assembly Instructions

PCB Assembly

1. Component Placement
2. Soldering Process
3. Quality Checks

Step
Action
Quality Check
1
Place components
Orientation
2
Solder pins
Joint quality
3
Clean board
No residue
4
Visual inspection
No bridges

Mechanical Assembly

Component
Mounting Location
Considerations
Control Box
Handlebar
Weather protection
Hall Sensor
Wheel hub
Magnet alignment
Display
Handlebar
Visibility
MOSFET
Heat sink
Thermal paste

Testing and Calibration

Initial Testing

Test
Procedure
Expected Result
Power Up
Apply power
Display activates
Sensor Check
Rotate wheel
Speed registers
Throttle
Apply throttle
Motor responds
Safety Checks
Emergency stop
System shuts down

Calibration Process

1. Speed Calibration
2. Current Limit Setting
3. Throttle Response Adjustment

Safety Features

Protection Systems

Feature
Trigger
Action
Overcurrent
>30A
PWM reduction
Overspeed
>25km/h
Speed limiting
Voltage Protection
<20V
System shutdown
Temperature
>80°C
Power reduction

Troubleshooting Guide

Problem
Possible Cause
Solution
No Display
Power issue
Check connections
No Speed Reading
Sensor alignment
Adjust magnet
Motor Cuts Out
Overcurrent
Check load
Erratic Behavior
EMI
Improve shielding

Frequently Asked Questions

Q1: What is the maximum speed this controller can handle?

A1: The controller is designed for speeds up to 25 km/h (15.5 mph), which is the legal limit in many countries for electric bikes. However, the speed limit can be adjusted in the code according to local regulations and safety requirements.

Q2: How much power can this controller handle?

A2: With the specified components (IRF3205 MOSFET and proper heat sinking), the controller can handle up to 30A continuous current at 48V, which equates to approximately 1440W. However, it's recommended to operate at 80% of this rating for reliability.

Q3: What modifications are needed for different voltage systems?

A3: For different voltage systems (24V, 36V, 48V), you'll need to:

• Adjust the voltage divider for battery monitoring
• Select an appropriate voltage regulator
• Update the voltage constants in the code
• Ensure all components are rated for the target voltage

Q4: How accurate is the speed measurement?

A4: The speed measurement accuracy depends on several factors:

• Proper calibration of wheel circumference
• Correct number of magnets on the wheel
• Proper positioning of the Hall effect sensor With proper setup, accuracy within ±2% can be achieved.

Q5: What maintenance is required for the controller?

A5: Regular maintenance includes:

• Checking all connections for tightness
• Inspecting the heat sink for dust and debris
• Verifying sensor alignment
• Updating calibration if wheel size changes
• Checking waterproof seals

Conclusion

Building an Arduino-based speed controller for an electric bike is a rewarding project that offers customization and learning opportunities. While the initial setup requires attention to detail, the result is a reliable and flexible control system that can be adapted to various e-bike configurations.