Multi-Drone Mesh Network

Overview

Multi-drone communication network is the foundation of drone swarm collaboration. In this project, you will learn how to build multi-drone communication networks.

What You’ll Learn

• Mesh network principles
• ESP-NOW protocol
• Network topology design
• Information sharing mechanisms

Materials Needed

Step 1: Understand Mesh Networks

Mesh network is a decentralized network topology where each node can communicate directly with other nodes.

Advantages of mesh networks:

• High reliability
• Good scalability
• Self-healing capability

Step 2: Network Topology Design

Design star topology or mesh topology, determine communication protocols and data formats.

Step 3: Code Implementation

Configure ESP-NOW for each drone, set peer list:

void mesh_init(void) {
    // 1. Initialize ESP-NOW
    esp_now_init();
    
    // 2. Add all drone MAC addresses to peer list
    uint8_t peer_macs[3][6] = {
        {0x11, 0x22, 0x33, 0x44, 0x55, 0x66}, // Drone 1 MAC
        {0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF}, // Drone 2 MAC
        {0x00, 0x11, 0x22, 0x33, 0x44, 0x55}  // Drone 3 MAC
    };
    
    for (int i = 0; i < 3; i++) {
        esp_now_add_peer(peer_macs[i], ESP_NOW_ROLE_COMBO, 0, NULL, 0);
    }
    
    // 3. Register data send/receive callback functions
    esp_now_register_send_cb(on_data_sent);
    esp_now_register_recv_cb(on_data_recv);
}

void mesh_broadcast_position(float x, float y, float z) {
    PositionData data;
    data.x = x;
    data.y = y;
    data.z = z;
    data.timestamp = esp_timer_get_time();
    
    // Broadcast to all drones
    esp_now_send(NULL, (uint8_t*)&data, sizeof(data));
}

Step 4: Compile, Flash and Test

1. Flash code to three drones separately
2. Power on and test, observe if drones can share position information

Troubleshooting

Communication fails

• Check if MAC addresses are correct
• Confirm ESP-NOW is initialized

Data loss

• Add data retransmission mechanism
• Increase communication frequency

Achievement

Congratulations! You have built multi-drone communication network, which is the foundation of drone swarm collaboration!

Next Steps

In the next project, you will learn how to implement multi-drone formation flight.

Continue to Project 09: Multi-Drone Formation →