290 PLC Based Electric Vehicle Motor Control System :: Quicker, easier and cheaper to make your own chip!

EV Motor Control System

A comprehensive electric vehicle motor control system implemented on Tiny Tapeout, featuring dual-mode operation (PLC/HMI), motor speed control with PWM, temperature monitoring, and various vehicle subsystems control.

How it works

This EV motor control system provides a complete solution for managing electric vehicle operations through a single ASIC. The design implements:

Core Architecture

The system operates on a state-machine based architecture with an 8-operation selector that controls different subsystems:

Operation 000: Power Control System
Operation 001: Headlight Management
Operation 010: Horn Control
Operation 011: Right Indicator Control
Operation 100: Motor Speed Calculation
Operation 101: PWM Generation for Motor Drive
Operation 110: Temperature Monitoring
Operation 111: System Reset/Status

Dual Control Interface

The system supports dual-mode operation:

PLC Mode (mode_select = 0): Industrial control via Programmable Logic Controller
HMI Mode (mode_select = 1): Human-Machine Interface for direct operator control

All control signals use XOR logic between PLC and HMI inputs, ensuring only one source can control each function at a time, preventing conflicts.

Motor Control System

Speed Calculation:

Takes 4-bit accelerator and brake inputs
Calculates speed as: speed = max(0, accelerator - brake)
Scales result to 8-bit motor speed output
Implements safety cutoff when brake > accelerator

PWM Generation:

Generates variable duty cycle PWM based on calculated speed
PWM frequency derived from main clock through divider
Automatic shutdown during temperature faults
8-bit resolution for smooth motor control

Safety Systems

Temperature Monitoring:

Simulates realistic temperature rise during motor operation
Triggers fault at 110°C with 5°C hysteresis (clears at 105°C)
Automatic speed reduction (50%) during overheating
Real-time temperature tracking with cooling simulation

Fault Protection:

System-wide shutdown capability
Temperature-based motor protection
Power-off safety for all subsystems

Input/Output Mapping

Dedicated Inputs (ui_in[7:0]):

[2:0]: Operation selector (8 operations)
[3]: PLC power control
[4]: HMI power control
[5]: Mode selector (PLC/HMI)
[6]: PLC headlight control
[7]: HMI headlight control

Bidirectional I/O (uio_in[7:0] input, uio_out[7:0] output):

uio_in[0]: PLC horn control
uio_in[1]: HMI horn control
uio_in[2]: PLC right indicator
uio_in[3]: HMI right indicator
uio_in[7:4]: 4-bit accelerator/brake data (time-multiplexed)
uio_out[7:0]: 8-bit motor speed output

Dedicated Outputs (uo_out[7:0]):

[0]: Power status LED
[1]: Headlight output
[2]: Horn output
[3]: Right indicator output
[4]: Motor PWM signal
[5]: Overheat warning LED
[7:6]: System status LEDs (enable, fault)

How to test

Basic Functionality Test

Power-Up Sequence:

- Set ena = 1, rst_n = 0
- Wait 10 clock cycles
- Set rst_n = 1
- Set operation_select = 3'b000
- Set either power_on_plc = 1 OR power_on_hmi = 1 (not both)
- Verify uo_out[0] = 1 (power status)

Headlight Test:

- Ensure system is powered on
- Set operation_select = 3'b001
- Set headlight_plc = 1, headlight_hmi = 0
- Verify uo_out[1] = 1 (headlight on)

Motor Speed Test:

- Set operation_select = 3'b100
- Set uio_in[7:4] = 4'd12 (accelerator)
- Wait 2 clock cycles for data_select toggle
- Set uio_in[7:4] = 4'd4 (brake)  
- Wait 5 clock cycles
- Verify uio_out = 8'd128 (expected: (12-4)<<4 = 128)

PWM Generation Test:

- Set operation_select = 3'b101
- Monitor uo_out[4] for multiple clock cycles
- Verify PWM signal toggles between 0 and 1
- Duty cycle should correspond to motor speed

Advanced Testing

Temperature Fault Testing:

Run motor at high speed (accelerator = 15, brake = 0) for extended time
Monitor uo_out[5] for overheat warning
Verify automatic speed reduction during fault

Mode Switching:

Test both PLC mode (mode_select = 0) and HMI mode (mode_select = 1)
Verify XOR logic prevents simultaneous control from both sources

Edge Cases:

Test brake > accelerator (should result in zero speed)
Test power-off behavior (all outputs should be disabled)
Test system reset (operation_select = 3'b111)

Test Sequence Example

# Complete test sequence in cocotb
await reset_sequence()
await test_power_control()
await test_headlight_control()  
await test_horn_control()
await test_motor_speed_calculation()
await test_pwm_generation()
await test_temperature_monitoring()
await test_mode_selection()
await test_edge_cases()

External hardware

The following external hardware components are recommended for a complete EV motor control implementation:

Required Components

Motor Drive Circuit:

3-Phase BLDC Motor (rated for vehicle application)
Motor Driver IC (e.g., DRV8305, DRV8323) - connects to PWM output (uo_out[4])
Gate Driver Circuit for high-current switching
Current Sense Resistors (0.01Ω, 2W) for overcurrent protection

Power Supply:

12V/24V Vehicle Battery connection
5V Regulator (LM7805 or switching regulator) for logic power
Power MOSFETs (IRFZ44N or similar) for high-current switching

Interface Connectors:

DB9 or DB15 Connector for PLC interface connection
Touch Screen HMI Panel (7" recommended) for operator interface
CAN Bus Interface (MCP2515 + MCP2551) for vehicle network communication

Recommended PMODs

PMOD Connectors for Easy Integration:

PMOD Motor - PWM motor control board
- Connects to uo_out[4] (PWM signal)
- Provides buffered outputs for motor drivers
PMOD LED8 - Status indicator array
- Connects to uo_out[7:0] for visual status display
- Shows power, headlight, horn, indicator, PWM, fault, and system status
PMOD Switch - Manual input controls
- Connects to ui_in[7:0] for manual operation mode
- Provides physical switches for testing
PMOD Thermocouple - Real temperature sensing
- Can replace simulated temperature monitoring
- Provides actual motor temperature feedback

Vehicle Integration Hardware

Lighting Systems:

Headlight Relays (12V automotive relays) - controlled by uo_out[1]
Horn Relay and Horn Assembly - controlled by uo_out[2]
LED Indicator Lights - controlled by uo_out[3]

Sensors and Feedback:

Hall Effect Accelerator Pedal - provides analog input for uio_in[7:4]
Brake Pressure Sensor - provides brake input data
Temperature Sensors (DS18B20 or thermistors) for motor and controller monitoring

Safety Systems:

Emergency Stop Switch - hardware override for immediate shutdown
Cooling Fan - controlled by overheat warning (uo_out[5])
Fuses and Circuit Breakers for overcurrent protection

Connection Diagram

TinyTapeout Chip
├── ui_in[7:0] → Input switches/PLC interface
├── uo_out[7:0] → LED indicators/Relays/PWM output
├── uio_in[7:4] → Accelerator/Brake sensors
├── uio_out[7:0] → Motor speed display/CAN interface
└── Power: 5V regulated, GND

External Power: 12V/24V vehicle battery
Motor: 3-phase BLDC + driver circuit
HMI: 7" touchscreen panel
PLC: Industrial controller interface

Safety Considerations

Isolated Power Supplies for logic and motor circuits
Optical Isolation for PLC/HMI interfaces
Emergency Stop Circuits with hardware override capability
Thermal Management for high-power motor control
EMI Filtering for automotive electromagnetic compatibility

This hardware setup provides a complete, production-ready EV motor control system suitable for small electric vehicles, e-bikes, or prototype electric car applications.

#	Input	Output	Bidirectional
0	operation_select[0]	power_status	horn_plc (input)
1	operation_select[1]	headlight_out	horn_hmi (input)
2	operation_select[2]	horn_out	right_ind_plc (input)
3	power_on_plc	right_indicator	right_ind_hmi (input)
4	power_on_hmi	motor_pwm	motor_speed[0] (output)
5	mode_select	overheat_warning	motor_speed[1] (output)
6	headlight_plc	status_led[0]	motor_speed[2] (output)
7	headlight_hmi	status_led[1]	motor_speed[3] (output)

290 PLC Based Electric Vehicle Motor Control System