Automama EV – Electrical & Control Stack (Documentation)

Vehicle concept 3D model.

This repository documents the drive-by-wire electrical and control architecture of the Automama EV platform.
The system is designed for research, experimentation, and future autonomous driving integration.

The vehicle is fully electronic — no mechanical steering column or brake linkage is used.

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1. System Overview

Jetson Nano (Orin Super) — high-level host.

ESP32-S3 dev board — low-level real-time controller.

Layer	Hardware	Role
High-Level Host	Jetson Nano / Laptop	Sends control commands
Low-Level Real-Time Controller	ESP32-S3	Executes steering, braking, and throttle

The ESP32-S3 is always actuator master.
Jetson/Laptop only issues setpoints.

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2. Power Architecture

Electrical Power Flow Diagram

Electrical power flow diagram showing the 48V → 24V → 5V distribution and propulsion path.

48V Battery Pack
 ├──> BLDC Motor Controller → Propulsion
 ├──> 48→24V Buck (600W) → Steering & Brake Actuators
 └──> 24→5V Buck → ESP32-S3, Sensors, Display

600W 48V→24V buck converter (actuator supply).

LM2596 24V→5V buck converter (logic supply).

Example 10A buck converter.

Battery Example:

Example 12V battery cell (pack uses multiple in series for 48V).

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3. Actuation Systems

3.1 Steering System

BTS7960 H-bridge motor driver used for steering motor control.

Component	Description
Motor	380 kg·cm DC Gear Motor
Driver	BTS7960 high-current driver
Feedback	Rotary Encoder

380 kg·cm DC gear motor (steering actuator).

Rotary encoder for steering angle feedback.

Control Logic:

error = target_angle - encoder_angle

if |error| > deadband:
    drive motor toward target
else:
    stop motor

Recommended deadband: ±1.5° to ±3°

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3.2 Brake System (Drive-By-Wire)

24V linear actuator used for drive-by-wire braking.

Feedback Sensor:

Slide potentiometer (10k) for brake position feedback.

brake_level (0–100%)
     ↓
desired actuator stroke
     ↓
measured via slide potentiometer feedback

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3.3 Propulsion System

1000W 48V BLDC motor for propulsion.

BLDC motor controller (throttle analog input interface).

Throttle command:

PWM (ESP32) → Analog Throttle Input (BLDC Controller)

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4. Control Architecture

(Keyboard / Bluetooth / Jetson)
               ↓ Serial UART
             ESP32-S3
     ┌──────────┬──────────┬──────────┐
 Steering     Brake      Throttle
(Encoder)   (Slide Pot)   (PWM Out)

Optional Perception Module

Raspberry Pi camera.

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5. Serial Command Interface

Command	Example	Meaning
S<x>	S30	Set steering angle to +30°
B<x>	B75	Apply 75% braking
T<x>	T120	Set throttle PWM to 120
STOP	STOP	Emergency stop

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6. Firmware Structure (Automama_control_test/)

File	Purpose
Automama_control_test.ino	System main control loop
steering_control.ino	Steering control logic
brake_operation.ino	Brake actuator control
throttle.ino	Propulsion PWM control
read_data.ino	Encoder / potentiometer readings
serial_communication.ino	Serial command parser
manual_steering.ino	Local test/override mode
preference_manager.ino	Calibration & limits

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7. Wiring (ESP32-S3 DevKitC)

ESP32-S3 Pin	Name	Device	Notes
GPIO14	STEER_PWM	BTS7960	Motor speed control
GPIO15	STEER_DIR	BTS7960	Direction control
GPIO36	ENC_A	Rotary Encoder	Input
GPIO39	ENC_B	Rotary Encoder	Input
GPIO4	BRAKE_PWM	Actuator Driver	Speed control
GPIO5	BRAKE_DIR	Actuator Driver	Extend / Retract
GPIO34	BRAKE_FEEDBACK	Slide Pot	ADC input
GPIO16	THROTTLE_PWM	BLDC Controller	Throttle PWM
GPIO1 / GPIO3	UART TX/RX	Jetson / Laptop / BT Module	Command input
5V	Logic Power	LM2596	Must be stable
GND	Ground	All devices	Common ground required

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8. Safety & Failsafes

• No control signal >200ms → Throttle = 0 + Brake engaged
• Startup → Neutral Safe Mode
• Hard-limit travel protection in software
• Physical 48V emergency kill switch

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9. System Visuals

Vehicle During Real-World Testing

Vehicle during field testing.

Onboard Display View

Onboard display and monitoring interface.

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10. Contributors

Name	Profile
Nainaiu Rakhaine	GitHub
Ad-Deen Mahbub	GitHub

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11. License

Open for research and educational use.
Contact for commercial or industrial usage.