2024A-SW/components/ESP-NOW/ESP-NOW.c

/*
 * This program source code file is part of the KTag project.
 *
 * 🛡️ <https://ktag.clubk.club> 🃞
 *
 * Copyright © 2025 Joseph P. Kearney and the KTag developers.
 *
 * This program is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Affero General Public License as published by the Free
 * Software Foundation, either version 3 of the License, or (at your option) any
 * later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
 * details.
 *
 * There should be a copy of the GNU Affero General Public License in the LICENSE
 * file in the root of this repository.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <string.h>
#include <SystemK.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_system.h"
#include "esp_wifi.h"
#include "esp_mac.h"
#include "esp_event.h"
#include "esp_now.h"
//
#include "nvs_flash.h"

static const char *TAG = "ESP-NOW";

// Broadcast address (all 0xFF sends to all devices)
static uint8_t Broadcast_MAC[ESP_NOW_ETH_ALEN] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};

// Structure for the data to send
typedef struct
{
    uint32_t counter;
    char message[32];
} broadcast_data_t;

// ESP-NOW receive callback
static void ESPNOW_Recv_CB(const esp_now_recv_info_t *recv_info, const uint8_t *data, int len)
{
    if (recv_info == NULL || data == NULL || len <= 0)
    {
        KLOG_ERROR(TAG, "Receive callback error");
        return;
    }

    // Log sender MAC address
    KLOG_INFO(TAG, "Received from: " MACSTR ", RSSI: %d",
              MAC2STR(recv_info->src_addr), recv_info->rx_ctrl->rssi);

    // Parse received data
    if (len == sizeof(broadcast_data_t))
    {
        broadcast_data_t *recv_data = (broadcast_data_t *)data;
        KLOG_INFO(TAG, "Counter: %lu, Message: %s",
                  recv_data->counter, recv_data->message);
    }
    else
    {
        KLOG_WARN(TAG, "Unexpected data length: %d", len);
    }
}

// ESP-NOW send callback
static void ESPNOW_Send_CB(const wifi_tx_info_t *tx_info, esp_now_send_status_t status)
{
    if (tx_info == NULL)
    {
        KLOG_ERROR(TAG, "Send callback error: tx_info is NULL");
        return;
    }

    if (status == ESP_NOW_SEND_SUCCESS)
    {
        KLOG_INFO(TAG, "Send success to " MACSTR, MAC2STR(tx_info->des_addr));
    }
    else
    {
        KLOG_WARN(TAG, "Send failed to " MACSTR, MAC2STR(tx_info->des_addr));
    }
}

static esp_err_t Initialize_ESPNOW(void)
{
    esp_err_t ret = esp_now_init();
    if (ret != ESP_OK)
    {
        KLOG_ERROR(TAG, "ESP-NOW init failed: %s", esp_err_to_name(ret));
        return ret;
    }

    // Register send and receive callbacks
    esp_now_register_send_cb(ESPNOW_Send_CB);
    esp_now_register_recv_cb(ESPNOW_Recv_CB);

    // Add broadcast peer
    esp_now_peer_info_t peer_info = {};
    memcpy(peer_info.peer_addr, Broadcast_MAC, ESP_NOW_ETH_ALEN);
    peer_info.channel = 0; // Use current channel
    peer_info.ifidx = WIFI_IF_STA;
    peer_info.encrypt = false;

    ret = esp_now_add_peer(&peer_info);
    if (ret != ESP_OK)
    {
        KLOG_ERROR(TAG, "Failed to add broadcast peer: %s", esp_err_to_name(ret));
        return ret;
    }

    KLOG_INFO(TAG, "ESP-NOW initialized successfully");
    return ESP_OK;
}

// FreeRTOS task for periodic broadcast
static void ESPNOW_Task(void *pvParameters)
{
    broadcast_data_t data = {0};
    TickType_t last_wake = xTaskGetTickCount();
    const TickType_t period = pdMS_TO_TICKS(2000);

    KLOG_INFO(TAG, "ESP-NOW task started");

    while (1)
    {
        // Update data
        data.counter++;
        snprintf(data.message, sizeof(data.message), "Broadcast #%lu", data.counter);

        // Send broadcast
        esp_err_t ret = esp_now_send(Broadcast_MAC, (uint8_t *)&data, sizeof(data));
        if (ret != ESP_OK)
        {
            KLOG_ERROR(TAG, "Send error: %s", esp_err_to_name(ret));
        }

        // Wait for next period
        vTaskDelayUntil(&last_wake, period);
    }
}

static void Initialize_WiFi(void)
{
    ESP_ERROR_CHECK(esp_netif_init());
    ESP_ERROR_CHECK(esp_event_loop_create_default());

    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
    ESP_ERROR_CHECK(esp_wifi_set_storage(WIFI_STORAGE_RAM));
    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
    ESP_ERROR_CHECK(esp_wifi_start());

    KLOG_INFO(TAG, "WiFi initialized in station mode");
}

void Initialize_ESP_NOW(void)
{
    Initialize_WiFi();

    // Initialize ESP-NOW
    if (Initialize_ESPNOW() != ESP_OK)
    {
        KLOG_ERROR(TAG, "ESP-NOW initialization failed");
        return;
    }

    // Enable Long Range mode
    esp_wifi_set_protocol(WIFI_IF_STA, WIFI_PROTOCOL_LR);
    esp_wifi_set_protocol(WIFI_IF_AP, WIFI_PROTOCOL_LR);

    // Create broadcast task
    xTaskCreate(ESPNOW_Task, "ESP-NOW", 4096, NULL, 5, NULL);
}