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fix(esp_now): Fix broadcast example and use nullptr #11490

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2 changes: 1 addition & 1 deletion libraries/ESP_NOW/examples/ESP_NOW_Broadcast_Master/ESP_NOW_Broadcast_Master.ino
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Original file line number Diff line number Diff line change
Expand Up @@ -58,7 +58,7 @@ public:
uint32_t msg_count = 0;

// Create a broadcast peer object
ESP_NOW_Broadcast_Peer broadcast_peer(ESPNOW_WIFI_CHANNEL, WIFI_IF_STA, NULL);
ESP_NOW_Broadcast_Peer broadcast_peer(ESPNOW_WIFI_CHANNEL, WIFI_IF_STA, nullptr);

/* Main */

Expand Down
28 changes: 21 additions & 7 deletions libraries/ESP_NOW/examples/ESP_NOW_Broadcast_Slave/ESP_NOW_Broadcast_Slave.ino
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Expand Up @@ -52,7 +52,8 @@ public:
/* Global Variables */

// List of all the masters. It will be populated when a new master is registered
std::vector<ESP_NOW_Peer_Class> masters;
// Note: Using pointers instead of objects to prevent dangling pointers when the vector reallocates
std::vector<ESP_NOW_Peer_Class *> masters;

/* Callbacks */

Expand All @@ -62,13 +63,14 @@ void register_new_master(const esp_now_recv_info_t *info, const uint8_t *data, i
Serial.printf("Unknown peer " MACSTR " sent a broadcast message\n", MAC2STR(info->src_addr));
Serial.println("Registering the peer as a master");

ESP_NOW_Peer_Class new_master(info->src_addr, ESPNOW_WIFI_CHANNEL, WIFI_IF_STA, NULL);

masters.push_back(new_master);
if (!masters.back().add_peer()) {
ESP_NOW_Peer_Class *new_master = new ESP_NOW_Peer_Class(info->src_addr, ESPNOW_WIFI_CHANNEL, WIFI_IF_STA, nullptr);
if (!new_master->add_peer()) {
Serial.println("Failed to register the new master");
delete new_master;
return;
}
masters.push_back(new_master);
Comment on lines +66 to +72
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Copilot AI Jun 21, 2025

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[nitpick] Since master peers are now allocated using raw pointers and stored in a vector, consider using smart pointers (e.g., std::unique_ptr) to ensure proper resource management and avoid potential memory leaks.

Suggested change
ESP_NOW_Peer_Class *new_master = new ESP_NOW_Peer_Class(info->src_addr, ESPNOW_WIFI_CHANNEL, WIFI_IF_STA, nullptr);
if (!new_master->add_peer()) {
Serial.println("Failed to register the new master");
delete new_master;
return;
}
masters.push_back(new_master);
auto new_master = std::make_unique<ESP_NOW_Peer_Class>(info->src_addr, ESPNOW_WIFI_CHANNEL, WIFI_IF_STA, nullptr);
if (!new_master->add_peer()) {
Serial.println("Failed to register the new master");
return;
}
masters.push_back(std::move(new_master));

Copilot uses AI. Check for mistakes.

Serial.printf("Successfully registered master " MACSTR " (total masters: %zu)\n", MAC2STR(new_master->addr()), masters.size());
} else {
// The slave will only receive broadcast messages
log_v("Received a unicast message from " MACSTR, MAC2STR(info->src_addr));
Expand Down Expand Up @@ -103,11 +105,23 @@ void setup() {
}

// Register the new peer callback
ESP_NOW.onNewPeer(register_new_master, NULL);
ESP_NOW.onNewPeer(register_new_master, nullptr);

Serial.println("Setup complete. Waiting for a master to broadcast a message...");
}

void loop() {
delay(1000);
// Print debug information every 10 seconds
static unsigned long last_debug = 0;
if (millis() - last_debug > 10000) {
last_debug = millis();
Serial.printf("Registered masters: %zu\n", masters.size());
for (size_t i = 0; i < masters.size(); i++) {
if (masters[i]) {
Serial.printf(" Master %zu: " MACSTR "\n", i, MAC2STR(masters[i]->addr()));
}
}
}

delay(100);
}
13 changes: 8 additions & 5 deletions libraries/ESP_NOW/examples/ESP_NOW_Network/ESP_NOW_Network.ino
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Original file line number Diff line number Diff line change
Expand Up @@ -123,7 +123,7 @@ public:
}

bool send_message(const uint8_t *data, size_t len) {
if (data == NULL || len == 0) {
if (data == nullptr || len == 0) {
log_e("Data to be sent is NULL or has a length of 0");
return false;
}
Expand Down Expand Up @@ -169,9 +169,12 @@ public:

/* Peers */

std::vector<ESP_NOW_Network_Peer *> peers; // Create a vector to store the peer pointers
ESP_NOW_Network_Peer broadcast_peer(ESP_NOW.BROADCAST_ADDR, 0, NULL); // Register the broadcast peer (no encryption support for the broadcast address)
ESP_NOW_Network_Peer *master_peer = nullptr; // Pointer to peer that is the master
// Create a vector to store the peer pointers
std::vector<ESP_NOW_Network_Peer *> peers;
// Register the broadcast peer (no encryption support for the broadcast address)
ESP_NOW_Network_Peer broadcast_peer(ESP_NOW.BROADCAST_ADDR, 0, nullptr);
// Pointer to the peer that is the master
ESP_NOW_Network_Peer *master_peer = nullptr;

/* Helper functions */

Expand Down Expand Up @@ -279,7 +282,7 @@ void setup() {
}

// Register the callback to be called when a new peer is found
ESP_NOW.onNewPeer(register_new_peer, NULL);
ESP_NOW.onNewPeer(register_new_peer, nullptr);

Serial.println("Setup complete. Broadcasting own priority to find the master...");
memset(&new_msg, 0, sizeof(new_msg));
Expand Down
42 changes: 21 additions & 21 deletions libraries/ESP_NOW/src/ESP32_NOW.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -9,12 +9,12 @@
#include "esp32-hal.h"
#include "esp_wifi.h"

static void (*new_cb)(const esp_now_recv_info_t *info, const uint8_t *data, int len, void *arg) = NULL;
static void *new_arg = NULL; // * tx_arg = NULL, * rx_arg = NULL,
static void (*new_cb)(const esp_now_recv_info_t *info, const uint8_t *data, int len, void *arg) = nullptr;
static void *new_arg = nullptr; // * tx_arg = nullptr, * rx_arg = nullptr,
static bool _esp_now_has_begun = false;
static ESP_NOW_Peer *_esp_now_peers[ESP_NOW_MAX_TOTAL_PEER_NUM];

static esp_err_t _esp_now_add_peer(const uint8_t *mac_addr, uint8_t channel, wifi_interface_t iface, const uint8_t *lmk, ESP_NOW_Peer *_peer = NULL) {
static esp_err_t _esp_now_add_peer(const uint8_t *mac_addr, uint8_t channel, wifi_interface_t iface, const uint8_t *lmk, ESP_NOW_Peer *_peer = nullptr) {
log_v(MACSTR, MAC2STR(mac_addr));
if (esp_now_is_peer_exist(mac_addr)) {
log_e("Peer Already Exists");
Expand All @@ -26,16 +26,16 @@ static esp_err_t _esp_now_add_peer(const uint8_t *mac_addr, uint8_t channel, wif
memcpy(peer.peer_addr, mac_addr, ESP_NOW_ETH_ALEN);
peer.channel = channel;
peer.ifidx = iface;
peer.encrypt = lmk != NULL;
peer.encrypt = lmk != nullptr;
if (lmk) {
memcpy(peer.lmk, lmk, ESP_NOW_KEY_LEN);
}

esp_err_t result = esp_now_add_peer(&peer);
if (result == ESP_OK) {
if (_peer != NULL) {
if (_peer != nullptr) {
for (uint8_t i = 0; i < ESP_NOW_MAX_TOTAL_PEER_NUM; i++) {
if (_esp_now_peers[i] == NULL) {
if (_esp_now_peers[i] == nullptr) {
_esp_now_peers[i] = _peer;
return ESP_OK;
}
Expand Down Expand Up @@ -67,8 +67,8 @@ static esp_err_t _esp_now_del_peer(const uint8_t *mac_addr) {
}

for (uint8_t i = 0; i < ESP_NOW_MAX_TOTAL_PEER_NUM; i++) {
if (_esp_now_peers[i] != NULL && memcmp(mac_addr, _esp_now_peers[i]->addr(), ESP_NOW_ETH_ALEN) == 0) {
_esp_now_peers[i] = NULL;
if (_esp_now_peers[i] != nullptr && memcmp(mac_addr, _esp_now_peers[i]->addr(), ESP_NOW_ETH_ALEN) == 0) {
_esp_now_peers[i] = nullptr;
break;
}
}
Expand All @@ -87,7 +87,7 @@ static esp_err_t _esp_now_modify_peer(const uint8_t *mac_addr, uint8_t channel,
memcpy(peer.peer_addr, mac_addr, ESP_NOW_ETH_ALEN);
peer.channel = channel;
peer.ifidx = iface;
peer.encrypt = lmk != NULL;
peer.encrypt = lmk != nullptr;
if (lmk) {
memcpy(peer.lmk, lmk, ESP_NOW_KEY_LEN);
}
Expand All @@ -111,17 +111,17 @@ static void _esp_now_rx_cb(const esp_now_recv_info_t *info, const uint8_t *data,
bool broadcast = memcmp(info->des_addr, ESP_NOW.BROADCAST_ADDR, ESP_NOW_ETH_ALEN) == 0;
log_v("%s from " MACSTR ", data length : %u", broadcast ? "Broadcast" : "Unicast", MAC2STR(info->src_addr), len);
log_buf_v(data, len);
if (!esp_now_is_peer_exist(info->src_addr) && new_cb != NULL) {
if (!esp_now_is_peer_exist(info->src_addr) && new_cb != nullptr) {
log_v("Calling new_cb, peer not found.");
new_cb(info, data, len, new_arg);
return;
}
//find the peer and call it's callback
for (uint8_t i = 0; i < ESP_NOW_MAX_TOTAL_PEER_NUM; i++) {
if (_esp_now_peers[i] != NULL) {
if (_esp_now_peers[i] != nullptr) {
log_v("Checking peer " MACSTR, MAC2STR(_esp_now_peers[i]->addr()));
}
if (_esp_now_peers[i] != NULL && memcmp(info->src_addr, _esp_now_peers[i]->addr(), ESP_NOW_ETH_ALEN) == 0) {
if (_esp_now_peers[i] != nullptr && memcmp(info->src_addr, _esp_now_peers[i]->addr(), ESP_NOW_ETH_ALEN) == 0) {
log_v("Calling onReceive");
_esp_now_peers[i]->onReceive(data, len, broadcast);
return;
Expand All @@ -133,7 +133,7 @@ static void _esp_now_tx_cb(const uint8_t *mac_addr, esp_now_send_status_t status
log_v(MACSTR " : %s", MAC2STR(mac_addr), (status == ESP_NOW_SEND_SUCCESS) ? "SUCCESS" : "FAILED");
//find the peer and call it's callback
for (uint8_t i = 0; i < ESP_NOW_MAX_TOTAL_PEER_NUM; i++) {
if (_esp_now_peers[i] != NULL && memcmp(mac_addr, _esp_now_peers[i]->addr(), ESP_NOW_ETH_ALEN) == 0) {
if (_esp_now_peers[i] != nullptr && memcmp(mac_addr, _esp_now_peers[i]->addr(), ESP_NOW_ETH_ALEN) == 0) {
_esp_now_peers[i]->onSent(status == ESP_NOW_SEND_SUCCESS);
return;
}
Expand Down Expand Up @@ -197,7 +197,7 @@ bool ESP_NOW_Class::end() {
}
//remove all peers
for (uint8_t i = 0; i < ESP_NOW_MAX_TOTAL_PEER_NUM; i++) {
if (_esp_now_peers[i] != NULL) {
if (_esp_now_peers[i] != nullptr) {
removePeer(*_esp_now_peers[i]);
}
}
Expand Down Expand Up @@ -249,7 +249,7 @@ size_t ESP_NOW_Class::write(const uint8_t *data, size_t len) {
if (len > ESP_NOW_MAX_DATA_LEN) {
len = ESP_NOW_MAX_DATA_LEN;
}
esp_err_t result = esp_now_send(NULL, data, len);
esp_err_t result = esp_now_send(nullptr, data, len);
if (result == ESP_OK) {
return len;
} else if (result == ESP_ERR_ESPNOW_NOT_INIT) {
Expand Down Expand Up @@ -292,7 +292,7 @@ ESP_NOW_Peer::ESP_NOW_Peer(const uint8_t *mac_addr, uint8_t channel, wifi_interf
}
chan = channel;
ifc = iface;
encrypt = lmk != NULL;
encrypt = lmk != nullptr;
if (encrypt) {
memcpy(key, lmk, 16);
}
Expand All @@ -305,7 +305,7 @@ bool ESP_NOW_Peer::add() {
if (added) {
return true;
}
if (_esp_now_add_peer(mac, chan, ifc, encrypt ? key : NULL, this) != ESP_OK) {
if (_esp_now_add_peer(mac, chan, ifc, encrypt ? key : nullptr, this) != ESP_OK) {
return false;
}
log_v("Peer added - " MACSTR, MAC2STR(mac));
Expand Down Expand Up @@ -350,7 +350,7 @@ bool ESP_NOW_Peer::setChannel(uint8_t channel) {
if (!_esp_now_has_begun || !added) {
return true;
}
return _esp_now_modify_peer(mac, chan, ifc, encrypt ? key : NULL) == ESP_OK;
return _esp_now_modify_peer(mac, chan, ifc, encrypt ? key : nullptr) == ESP_OK;
}

wifi_interface_t ESP_NOW_Peer::getInterface() const {
Expand All @@ -362,22 +362,22 @@ bool ESP_NOW_Peer::setInterface(wifi_interface_t iface) {
if (!_esp_now_has_begun || !added) {
return true;
}
return _esp_now_modify_peer(mac, chan, ifc, encrypt ? key : NULL) == ESP_OK;
return _esp_now_modify_peer(mac, chan, ifc, encrypt ? key : nullptr) == ESP_OK;
}

bool ESP_NOW_Peer::isEncrypted() const {
return encrypt;
}

bool ESP_NOW_Peer::setKey(const uint8_t *lmk) {
encrypt = lmk != NULL;
encrypt = lmk != nullptr;
if (encrypt) {
memcpy(key, lmk, 16);
}
if (!_esp_now_has_begun || !added) {
return true;
}
return _esp_now_modify_peer(mac, chan, ifc, encrypt ? key : NULL) == ESP_OK;
return _esp_now_modify_peer(mac, chan, ifc, encrypt ? key : nullptr) == ESP_OK;
}

size_t ESP_NOW_Peer::send(const uint8_t *data, int len) {
Expand Down
4 changes: 2 additions & 2 deletions libraries/ESP_NOW/src/ESP32_NOW.h
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Expand Up @@ -20,7 +20,7 @@ class ESP_NOW_Class : public Print {
ESP_NOW_Class();
~ESP_NOW_Class();

bool begin(const uint8_t *pmk = NULL /* 16 bytes */);
bool begin(const uint8_t *pmk = nullptr /* 16 bytes */);
bool end();

int getTotalPeerCount();
Expand Down Expand Up @@ -50,7 +50,7 @@ class ESP_NOW_Peer {
bool remove();
size_t send(const uint8_t *data, int len);

ESP_NOW_Peer(const uint8_t *mac_addr, uint8_t channel = 0, wifi_interface_t iface = WIFI_IF_AP, const uint8_t *lmk = NULL);
ESP_NOW_Peer(const uint8_t *mac_addr, uint8_t channel = 0, wifi_interface_t iface = WIFI_IF_AP, const uint8_t *lmk = nullptr);

public:
virtual ~ESP_NOW_Peer() {}
Expand Down
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