basic esp32 sketch to broadcast config message on setup and then recieve and print messages

host/esp32/lib/espnow/src/espnow.cpp

+#include <esp_now.h>
+#include <esp_wifi.h>
+#include "espnow.hpp"
+#include "WiFi.h"
+#include <ESP32Time.h>
+
+uint8_t BROADCAST_MAC[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}; // leaving this in as possible backup
+esp_now_peer_info_t hostInfo;
+data_struct lastData;
+ESP32Time rtc;
+
+void on_data_sent(const uint8_t *mac_addr, esp_now_send_status_t status){
+}
+
+
+void on_data_recv(const uint8_t *mac, const uint8_t *incomingData, int len){
+    memcpy(&lastData, incomingData, sizeof(lastData));
+    for(int i=0; i<NUM_SENSORS; i++){
+        Serial.println(lastData.identifiers[i] + lastData.values[i]);
+    }
+    Serial.println("at " + lastData.timestamp);
+}
+
+esp_err_t espnow_setup(){
+    esp_err_t result;
+    WiFi.mode(WIFI_STA);
+    result = esp_now_init();
+    if(result != ESP_OK){
+        //initialization failed
+        return result; // not sure about this
+    }
+
+    hostInfo.channel = 0;
+    hostInfo.encrypt = true;
+    result = esp_now_add_peer(&hostInfo);
+    if(result != ESP_OK){
+        //peer couldn't be added
+        return result;
+    }
+
+    esp_now_register_recv_cb(on_data_recv);
+    esp_now_register_send_cb(on_data_sent);
+
+    return ESP_OK;
+}
+
+Message :: Message(){
+    memcpy(BROADCAST_MAC, recipient, sizeof(BROADCAST_MAC));
+    config = (config_struct*) malloc(sizeof(config_struct));
+    esp_wifi_get_mac(WIFI_IF_STA, config->host);
+    config->time_millis = rtc.getMillis();
+}
+
+esp_err_t Message::send(){
+    return esp_now_send(recipient, (uint8_t *) &config, sizeof(config));
+}
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host/esp32/lib/espnow/src/espnow.hpp

+#ifndef _ESPNOW
+#define _ESPNOW
+
+#define NUM_SENSORS 10
+
+typedef struct data_struct{
+    int identifiers[NUM_SENSORS];
+    float values[NUM_SENSORS];
+    long timestamp; //maybe make this array
+}data_struct;
+
+typedef struct config_struct{
+    uint8_t host[6];
+    long time_millis;
+}config_struct;
+
+class Message{
+    public:
+        Message();
+        esp_err_t send();
+        uint8_t recipient[6];
+
+    private:
+        config_struct *config;
+
+};
+
+esp_err_t espnow_setup();
+
+#endif
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host/esp32/platformio.ini

@@ -12,3 +12,4 @@
 platform = espressif32
 board = esp32-c3-devkitm-1
 framework = arduino
+lib_deps = fbiego/ESP32Time@^2.0.0

host/esp32/src/main.cpp

 #include <Arduino.h>
+#include <esp_wifi.h>
+#include "WiFi.h"
+#include "espnow.hpp"
 
 void setup() {
   // put your setup code here, to run once:
+  Serial.begin(115200);
+  while(!Serial);
+  WiFi.mode(WIFI_STA);
+  espnow_setup();
+
+  Message* msg = new Message;
+  msg->send();
 }
 
 void loop() {
   // put your main code here, to run repeatedly:
+  Serial.println("No message...");
 }
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