ESP-NOW sscanf( fails to identify MAC address

Pcborges
Posts: 37
Joined: Thu Aug 09, 2018 9:56 pm

ESP-NOW sscanf( fails to identify MAC address

Postby Pcborges » Sat May 01, 2021 10:36 pm

Hi, I am trying to implement ESP NOW in a way that I only need to enter at my master the MAC address of the peer.
Then I send the master's MAC to the peer so the peer can register the master's received MAC.
I succeeded to send the Master's MAC to the peer but so far I failed to have the peer register the master.
The code of the peer is as below, the Master works fine.

Code: Select all

#include <esp_now.h>
#include <WiFi.h>

// INIT MAC Address of your receiver 
uint8_t broadcastAddress[6] = { 0 };

// Define variables to be sent
float temperature;
float humidity;
float pressure;
char  localmac[18];

// Define variables to store incoming readings
float incomingTemp;
float incomingHum;
float incomingPres;
char  incomingMac[18];

// Variable to store if sending data was successful
String success;

//Structure example to send data
//Must match the receiver structure
typedef struct struct_message {
    float temp;
    float hum;
    float pres;
    char  hmac[18];
} struct_message;

// Create a struct_message called variablesToBeSent to hold sensor readings
struct_message variablesToBeSent;

// Create a struct_message to hold incoming sensor readings
struct_message incomingReadings;

// Callback when data is sent
void OnDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) {
  Serial.print("\r\nLast Packet Send Status:\t");
  Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
  if (status ==0){
    success = "Delivery Success";
  }
  else{
    success = "Delivery Fail";
  }
}

// Callback when data is received
void OnDataRecv(const uint8_t * mac, const uint8_t *incomingData, int len) {
  memcpy(&incomingReadings, incomingData, sizeof(incomingReadings));
  Serial.print("Bytes received: ");
  Serial.println(len);
  incomingTemp = incomingReadings.temp;
  incomingHum  = incomingReadings.hum;
  incomingPres = incomingReadings.pres;
  strcpy(incomingMac, incomingReadings.hmac);
  success = str2mac(incomingMac, broadcastAddress);          <--gets MAC from master and FAIL to load into broadcastAddress

  Serial.println("broadcastAddress: ");                              <-- see console printout attached
  if (success) {
    for (int i=0; i<6; i++) {
      printf("%02X:",broadcastAddress[i]);
      Serial.println("");
    }
  }
}

int str2mac(const char* mac, uint8_t* broadcastAddress){
  Serial.print("str2mac: #");
  Serial.print(mac);                           <--- MAC from Master OK, sscanf( below fails to parse contents of broadcastAddress
  Serial.print("# lenght: ");
  Serial.println(sizeof(mac));
  if( 6 == sscanf( mac, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",&broadcastAddress[0], &broadcastAddress[1], &broadcastAddress[2],&broadcastAddress[3], &broadcastAddress[4], &broadcastAddress[5] ) ){
    return 1;
  }else{
    return 0;
  }
}
 
void setup() {
  // Init Serial Monitor
  Serial.begin(115200);

  // Set device as a Wi-Fi Station
  WiFi.mode(WIFI_STA);

  // Init ESP-NOW
  if (esp_now_init() != ESP_OK) {
    Serial.println("Error initializing ESP-NOW");
    return;
  }

  // Once ESPNow is successfully Init, we will register for Send CB to
  // get the status of Trasnmitted packet
  esp_now_register_send_cb(OnDataSent);

  //int success = str2mac("24:0A:C4:BA:99:4C", broadcastAddress);  //dest COM camera
  //int success = str2mac("24:6F:28:46:95:B0", broadcastAddress);  //dest SEM camera  
  //if (success) {
  //  for (int i=0; i<6; i++) {
  //    printf("%02X:",broadcastAddress[i]);
  //    Serial.println("");
  //  }
  //}  
  registerPier();
/*
  // Register peer
  esp_now_peer_info_t peerInfo;
  memcpy(peerInfo.peer_addr, broadcastAddress, 6);
  peerInfo.channel = 0;  
  peerInfo.encrypt = false;
  
  // Add peer        
  if (esp_now_add_peer(&peerInfo) != ESP_OK){
    Serial.println("Failed to add peer");
    return;
  }
*/

  // Register for a callback function that will be called when data is received
  esp_now_register_recv_cb(OnDataRecv);
}

void registerPier(){
  // Register peer
  esp_now_peer_info_t peerInfo;
  memcpy(peerInfo.peer_addr, broadcastAddress, 6);
  peerInfo.channel = 0;  
  peerInfo.encrypt = false;
  
  // Add peer        
  if (esp_now_add_peer(&peerInfo) != ESP_OK){
    Serial.println("Failed to add peer");
    return;
  }  
}


void loop() {
  // Set values to send
  variablesToBeSent.temp = 26;
  variablesToBeSent.hum  = 77;
  variablesToBeSent.pres = 1033;
  strcpy(variablesToBeSent.hmac, "22:33:44:55:66");   //send my own mac here

  // Send message via ESP-NOW
  esp_err_t result = esp_now_send(broadcastAddress, (uint8_t *) &variablesToBeSent, sizeof(variablesToBeSent));
   
  if (result == ESP_OK) {
    Serial.println("Sent with success");
  }
  else {
    Serial.println("Error sending the data");
  }
  updateDisplay();
  delay(10000);
}

void updateDisplay(){
  // Display Readings in Serial Monitor
  Serial.println("INCOMING READINGS");
  Serial.print("Temperature: ");
  Serial.print(incomingReadings.temp);
  Serial.println(" ºC");
  Serial.print("Humidity: ");
  Serial.print(incomingReadings.hum);
  Serial.println(" %");
  Serial.print("Pressure: ");
  Serial.print(incomingReadings.pres);
  Serial.println(" hPa");
  Serial.print("Mac: ");
  Serial.print(incomingReadings.hmac);  
  Serial.println();
}
Console printout:
Error sending the data
19:34:40.905 -> INCOMING READINGS
19:34:40.905 -> Temperature: 26.00 ºC
19:34:40.952 -> Humidity: 77.00 %
19:34:40.952 -> Pressure: 1033.00 hPa
19:34:40.952 -> Mac: 24:6F:28:46:95:B0 <-- MAC from master station arrives OK
19:34:42.826 -> Bytes received: 32
19:34:42.826 -> str2mac: #24:6F:28:46:95:B0# lenght: 4 <-- lenght should be 18 not 4 ------------ERROR ERROR
19:34:42.826 -> broadcastAddress:
19:34:42.826 ->
19:34:42.826 ->
19:34:42.826 ->
19:34:42.826 ->
19:34:42.826 ->
19:34:42.826 ->

Thanks

WiFive
Posts: 3529
Joined: Tue Dec 01, 2015 7:35 am

Re: ESP-NOW sscanf( fails to identify MAC address

Postby WiFive » Sat May 01, 2021 10:42 pm

sizeof does not return the length of a string

Pcborges
Posts: 37
Joined: Thu Aug 09, 2018 9:56 pm

Re: ESP-NOW sscanf( fails to identify MAC address

Postby Pcborges » Sat May 01, 2021 11:11 pm

"sizeof does not return the length of a string"

OK, I was sure the size of a char array could be found with sizeof, will research, thanks.
But my real problem is why this:

Code: Select all

sscanf( mac, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",&broadcastAddress[0], &broadcastAddress[1], &broadcastAddress[2],&broadcastAddress[3], &broadcastAddress[4], &broadcastAddress[5] ) 
Returns am empty broadcastAddress.

Thanks

Pcborges
Posts: 37
Joined: Thu Aug 09, 2018 9:56 pm

Re: ESP-NOW sscanf( fails to identify MAC address

Postby Pcborges » Sun May 02, 2021 12:52 am

Just an update I just cannot explain...

If I leave the sketch to run for a while it eventually prints a big broadcastAddress, please check at the end.
What am I doing wrong?

Code: Select all

21:48:45.243 -> ets Jun  8 2016 00:22:57
21:48:45.243 -> 
21:48:45.243 -> rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
21:48:45.243 -> configsip: 0, SPIWP:0xee
21:48:45.243 -> clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
21:48:45.243 -> mode:DIO, clock div:2
21:48:45.243 -> load:0x3fff0018,len:4
21:48:45.243 -> load:0x3fff001c,len:1216
21:48:45.243 -> ho 0 tail 12 room 4
21:48:45.243 -> load:0x40078000,len:10944
21:48:45.243 -> load:0x40080400,len:6360
21:48:45.243 -> entry 0x400806b4
21:48:46.512 -> E (2003) ESPNOW: Peer interface is invalid
21:48:46.512 -> Failed to add peer
21:48:46.512 -> Error sending the data
21:48:46.512 -> INCOMING READINGS
21:48:46.512 -> Temperature: 0.00 ºC
21:48:46.512 -> Humidity: 0.00 %
21:48:46.512 -> Pressure: 0.00 hPa
21:48:46.512 -> Mac: 
21:48:52.753 -> Bytes received: 32
21:48:52.753 -> -> broadcastAddress: 
21:48:52.753 -> ,
21:48:52.753 -> ,
21:48:52.753 -> ,
21:48:52.753 -> ,
21:48:52.753 -> ,
21:48:52.753 -> ,
21:48:56.556 -> Error sending the data
21:48:56.556 -> INCOMING READINGS
21:48:56.556 -> Temperature: 26.00 ºC
21:48:56.556 -> Humidity: 77.00 %
21:48:56.556 -> Pressure: 1033.00 hPa
21:48:56.556 -> Mac: 24:6F:28:46:95:B0
21:49:02.790 -> Bytes received: 32
21:49:02.790 -> -> broadcastAddress: 
21:49:02.790 -> ,
21:49:02.790 -> ,
21:49:02.790 -> ,
21:49:02.790 -> ,
21:49:02.790 -> ,
21:49:02.790 -> ,
21:49:06.510 -> Error sending the data
21:49:06.510 -> INCOMING READINGS
21:49:06.556 -> Temperature: 26.00 ºC
21:49:06.556 -> Humidity: 77.00 %
21:49:06.556 -> Pressure: 1033.00 hPa
21:49:06.556 -> Mac: 24:6F:28:46:95:B0
21:49:12.763 -> Bytes received: 32
21:49:12.763 -> -> broadcastAddress: 
21:49:12.763 -> ,
21:49:12.763 -> ,
21:49:12.763 -> ,
21:49:12.763 -> ,
21:49:12.763 -> ,
21:49:12.763 -> ,
21:49:16.503 -> Error sending the data
21:49:16.550 -> INCOMING READINGS
21:49:16.550 -> Temperature: 26.00 ºC
21:49:16.550 -> Humidity: 77.00 %
21:49:16.550 -> Pressure: 1033.00 hPa
21:49:16.550 -> Mac: 24:6F:28:46:95:B0
21:49:22.787 -> Bytes received: 32
21:49:22.787 -> -> broadcastAddress: 
21:49:22.787 -> ,
21:49:22.787 -> ,
21:49:22.787 -> ,
21:49:22.787 -> ,
21:49:22.787 -> ,
21:49:22.787 -> ,
21:49:26.523 -> Error sending the data
21:49:26.523 -> INCOMING READINGS
21:49:26.523 -> Temperature: 26.00 ºC
21:49:26.523 -> Humidity: 77.00 %
21:49:26.523 -> Pressure: 1033.00 hPa
21:49:26.523 -> Mac: 24:6F:28:46:95:B0
21:49:32.775 -> Bytes received: 32
21:49:32.775 -> -> broadcastAddress: 
21:49:32.775 -> ,
21:49:32.775 -> ,
21:49:32.775 -> ,
21:49:32.775 -> ,
21:49:32.775 -> ,
21:49:32.775 -> ,
21:49:36.528 -> Error sending the data
21:49:36.528 -> INCOMING READINGS
21:49:36.528 -> Temperature: 26.00 ºC
21:49:36.528 -> Humidity: 77.00 %
21:49:36.528 -> Pressure: 1033.00 hPa
21:49:36.528 -> Mac: 24:6F:28:46:95:B0
21:49:42.752 -> Bytes received: 32
21:49:42.752 -> -> broadcastAddress: 
21:49:42.752 -> ,
21:49:42.752 -> ,
21:49:42.752 -> ,
21:49:42.752 -> ,
21:49:42.752 -> ,
21:49:42.752 -> ,
21:49:46.521 -> Error sending the data
21:49:46.521 -> INCOMING READINGS
21:49:46.521 -> Temperature: 26.00 ºC
21:49:46.521 -> Humidity: 77.00 %
21:49:46.521 -> Pressure: 1033.00 hPa
21:49:46.521 -> Mac: 24:6F:28:46:95:B0
21:49:52.779 -> Bytes received: 32
21:49:52.779 -> -> broadcastAddress: 
21:49:52.779 -> ,
21:49:52.779 -> ,
21:49:52.779 -> ,
21:49:52.779 -> ,
21:49:52.779 -> ,
21:49:52.779 -> ,
21:49:56.541 -> Error sending the data
21:49:56.541 -> INCOMING READINGS
21:49:56.541 -> Temperature: 26.00 ºC
21:49:56.541 -> Humidity: 77.00 %
21:49:56.541 -> Pressure: 1033.00 hPa
21:49:56.541 -> Mac: 24:6F:28:46:95:B0
21:50:02.786 -> Bytes received: 32
21:50:02.786 -> -> broadcastAddress: 
21:50:02.786 -> 24:6F:28:46:95:B0:24:6F:28:46:95:B0:24:6F:28:46:95:B0:24:6F:28:46:95:B0:24:6F:28:46:95:B0:24:6F:28:46:95:B0:24:6F:28:46:95:B0:24,
21:50:02.786 -> ,
21:50:02.786 -> ,
21:50:02.786 -> ,

Pcborges
Posts: 37
Joined: Thu Aug 09, 2018 9:56 pm

Re: ESP-NOW sscanf( fails to identify MAC address

Postby Pcborges » Sun May 02, 2021 1:35 am

Some changes in the code:

Code: Select all

// Callback when data is received
void OnDataRecv(const uint8_t * mac, const uint8_t *incomingData, int len) {
  memcpy(&incomingReadings, incomingData, sizeof(incomingReadings));
  Serial.print("Bytes received: ");
  Serial.println(len);
  incomingTemp = incomingReadings.temp;
  incomingHum  = incomingReadings.hum;
  incomingPres = incomingReadings.pres;
  strcpy(incomingMac, incomingReadings.hmac);
  registerPier(incomingMac);
}

void registerPier(const char* serverMAC){
  
  getMAC_OK = str2mac(serverMAC, broadcastAddress);

  Serial.println("|---> broadcastAddress: ");
  if (getMAC_OK) {
    for (int i=0; i<6; i++) {
      printf("%02X:",broadcastAddress[i]);
      Serial.print(",");
    }
    Serial.println("");
  }
  
  // Register peer
  esp_now_peer_info_t peerInfo;
  memcpy(peerInfo.peer_addr, broadcastAddress, 6);
  peerInfo.channel = 0;  
  peerInfo.encrypt = false;
  
  // Add peer        
  if (esp_now_add_peer(&peerInfo) != ESP_OK){
    Serial.println("Failed to add peer");
    return;
  }  
}
Console printout:

Code: Select all

2:30:01.819 -> Error sending the data
22:30:01.819 -> INCOMING READINGS
22:30:01.819 -> Temperature: 0.00 ºC
22:30:01.819 -> Humidity: 0.00 %
22:30:01.819 -> Pressure: 0.00 hPa
22:30:01.819 -> Mac: 
22:30:02.714 -> Bytes received: 32
22:30:02.761 -> |---> broadcastAddress: 
22:30:02.761 -> ,,,,,,
22:30:02.761 -> 24:6F:28:46:95:B0:E (2924) ESPNOW: Peer interface is invalid
22:30:02.761 -> Failed to add peer
22:30:11.849 -> Error sending the data
22:30:11.849 -> INCOMING READINGS
22:30:11.849 -> Temperature: 26.00 ºC
22:30:11.849 -> Humidity: 77.00 %
22:30:11.849 -> Pressure: 1033.00 hPa
22:30:11.849 -> Mac: 24:6F:28:46:95:B0
22:30:12.749 -> Bytes received: 32
22:30:12.749 -> |---> broadcastAddress: 
22:30:12.749 -> ,,,,,,                                                        <----- Why empty?
22:30:12.749 -> 24:6F:28:46:95:B0:E (12923) ESPNOW: Peer interface is invalid         //(:E) Where does it come from?
22:30:12.749 -> Failed to add peer
22:30:21.845 -> Error sending the data
22:30:21.845 -> INCOMING READINGS
22:30:21.845 -> Temperature: 26.00 ºC
22:30:21.845 -> Humidity: 77.00 %
22:30:21.845 -> Pressure: 1033.00 hPa
22:30:21.845 -> Mac: 24:6F:28:46:95:B0
22:30:22.783 -> Bytes received: 32
22:30:22.783 -> |---> broadcastAddress:

ESP_Sprite
Posts: 8922
Joined: Thu Nov 26, 2015 4:08 am

Re: ESP-NOW sscanf( fails to identify MAC address

Postby ESP_Sprite » Mon May 10, 2021 6:55 am

liyon01: Suggest you make that into its own separate topic, as your issue seems to have nothing to do with the one talked about here.

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