RC-Robot_NovaGlide

A modular robot control system for ESP32-C3 with wireless control (ESP-NOW), telemetry (MQTT), and comprehensive sensor integration.

🏗️ Project Structure

ESP-IDF_NovaGlide/
├── main/
│   ├── ESP-IDF_NovaGlide.c    ✅ Main application entry point
│   ├── system_init.c/h        # System initialization (NVS)
│   ├── scheduler.c/h          ✅ Unified subsystem update loop based on FreeRTOS scheduler
│   └── control_task.c/h       ✅ RC Robot control task (joystick → motors)
│
└── subsystems/
    ├── motors/                # Motor PWM control
    │   ├── motors.c/h
    │   └── CMakeLists.txt
    │
    ├── adc/                   # Joystick ADC reading
    │   ├── adc.c/h
    │   └── CMakeLists.txt
    │
    ├── sensors/               # All sensor drivers
    │   ├── temp_sensor.c/h        # ESP32-C3 internal temperature
    │   ├── ina219_sensor.c/h      # Battery voltage/current monitor
    │   ├── ultrasonic_sensor.c/h  # Distance sensor
    │   └── CMakeLists.txt
    │
    ├── connectivity/          # Wireless communication
    │   ├── wifi_sys/              # WiFi initialization
    │   ├── espnow_sys/            ✅ ESP-NOW wireless control
    │   └── mqtt_sys/              # MQTT telemetry
    │
    ├── controls/              # Control algorithms
    │   ├── joystick.c/h           # Joystick mixing algorithm
    │   └── CMakeLists.txt
    │
    └── ui/                    # User interface (LED, buttons)
        ├── ui.c/h
        └── CMakeLists.txt

RC-Robot 🔑 Key Components

Motors Subsystem

Location: subsystems/motors/

Purpose: Controls 4 DC motors using PWM (left/right, forward/reverse, spin left/right)

Key Functions:

motor_system_init() - Initialize LEDC timers and channels
motor_set_pwm(left, right) - Set signed PWM values (-8191 to +8190)
motor_update() - Apply PWM to hardware (called by scheduler)

GPIO Pins:

Motor 1 (Left-side Forward): GPIO 6
Motor 2 (Right-side Forward): GPIO 5
Motor 3 (Left-side Reverse): GPIO 4
Motor 4 (Right-side Reverse): GPIO 7

ESP-NOW Subsystem

Location: subsystems/connectivity/espnow_sys/

Purpose: Receives wireless joystick data from remote control

Key Functions:

espnow_system_init() - Initialize ESP-NOW
espnow_recv_cb() - Callback when data received
Data structure: sensors_data_t struct with x_axis, y_axis values

MQTT Subsystem

Location: subsystems/connectivity/mqtt_sys/

Purpose: Publishes robot telemetry to MQTT broker

MQTT Topics:

/bitrider/temp - Internal temperature (°C)
/bitrider/battery_voltage - Battery voltage (V)
/bitrider/sys_current - System current (mA)
/bitrider/sys_power - System power (mW)
/bitrider/pwm_left - Left motor PWM value
/bitrider/pwm_right - Right motor PWM value

Configuration:

Broker: mqtt://techquadbit.net
WiFi SSID: IoT_bots
Password: 208208208

Joystick Control

Location: subsystems/controls/joystick.c

Purpose: Converts joystick X/Y values to differential motor PWM

Algorithm:

joystick_mix(x_raw, y_raw, &pwm_left, &pwm_right)

Normalizes joystick input to [-1, +1]
Applies differential steering (k = 0.4)
Outputs signed PWM values for each motor side

Sensors

Temperature Sensor

Type: ESP32-C3 internal sensor
Update Rate: Every 5 seconds
Range: 10°C to 50°C

INA219 Power Monitor

Interface: I2C (GPIO 3: SDA, GPIO 2: SCL)
Measures: Battery voltage, current, power
Update Rate: Every 2.5 seconds
Shunt Resistor: 100mΩ

Ultrasonic Distance Sensor

GPIO Pins: Trigger: GPIO 4, Echo: GPIO 5
Update Rate: Every 1 second
Max Range: 400 cm

UI Subsystem

Location: subsystems/ui/

Features:

LED blinking (GPIO 10) - 500ms interval
Button interrupt handling (GPIO 8)

🔄 System Architecture

Initialization Flow

System Init - NVS flash initialization
WiFi Init - Connect to WiFi network
Subsystem Init - Initialize all components
Task Creation - Start control and telemetry tasks
Scheduler Start - Begin main update loop

Main Tasks

Scheduler Task (50ms / 20Hz)

Updates all subsystems periodically
Calls update() function for each component
Priority: 10

Control Task (100ms / 10Hz)

Reads joystick data from ESP-NOW
Applies mixing algorithm
Updates motor PWM values
Priority: 15

Telemetry Task (1000ms / 1Hz)

Collects sensor data
Publishes to MQTT broker
Priority: 5

📊 Data Flow

Remote Control (ESP-NOW)
    ↓
ESP-NOW Subsystem → sensors_data_t (x, y)
    ↓
Control Task → joystick_mix()
    ↓
Motor Subsystem → PWM
    ↓
Motors (Physical Hardware)

Sensors → Scheduler (periodic updates)
    ↓
Telemetry Task
    ↓
MQTT Broker → Monitoring Dashboard

🔧 Configuration

Motor PWM Configuration

Frequency: 7000 Hz
Resolution: 13-bit (0-8191)
Range: -8191 (full reverse) to +8190 (full forward)

WiFi Configuration

Edit subsystems/connectivity/wifi_sys/wifi_sys.h:

#define WIFI_SSID "your_ssid"
#define WIFI_PASSWORD "your_password"

MQTT Configuration

Edit subsystems/connectivity/mqtt_sys/mqtt_sys.h:

#define MQTT_BROKER_URI "mqtt://your_broker_ip"

🐛 Debugging

Enable Component Logging

Each subsystem has a TAG for logging:

ESP_LOGI(TAG, "Message");  // Info
ESP_LOGW(TAG, "Warning");  // Warning
ESP_LOGE(TAG, "Error");    // Error

Monitor Motor PWM Values

Motors log PWM values every second:

I (1234) MOTORS: PWM L/R: 4000/3500 | M1:4000 M2:3500 M3:0 M4:0

Check Sensor Readings

I (5678) TEMP_SENSOR: Temperature: 32.50°C
I (9012) INA219: VBUS: 7.40V, I: 850.00mA, P: 6290.00mW
I (3456) ULTRASONIC: Distance: 45.23 cm

📝 Adding New Subsystems

Create directory: subsystems/your_subsystem/
Add source files: your_subsystem.c/h

Create CMakeLists.txt:

idf_component_register(
    SRCS "your_subsystem.c"
    INCLUDE_DIRS "."
    REQUIRES freertos)

Add to root CMakeLists.txt:

set(EXTRA_COMPONENT_DIRS 
    ...
    "subsystems/your_subsystem")

Include in main/scheduler.h and wire to scheduler

📚 Dependencies

ESP-IDF Components

freertos
esp_wifi
esp_netif
nvs_flash
mqtt
esp_driver_ledc
esp_driver_gpio
esp_adc

External Libraries (Managed Components)

esp-idf-lib/i2cdev - I2C device library
esp-idf-lib/ina219 - INA219 power monitor
esp-idf-lib/ultrasonic - HC-SR04 ultrasonic sensor

👥 Authors

Alexander Bobkov

NovaGlide RC Robot

ESP32 IoT gadgets by Alexander B

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