From b2ec27de1d2d4703a15f6397550a46896413828a Mon Sep 17 00:00:00 2001
From: Tomas Pilny <tomas.pilny@espressif.com>
Date: Fri, 19 Aug 2022 14:05:18 +0200
Subject: [PATCH 1/4] Removed option to change CHANNEL
---
.../examples/ESPNow/Basic/Master/Master.ino | 109 +++++++++---------
.../examples/ESPNow/Basic/Slave/Slave.ino | 5 +-
2 files changed, 54 insertions(+), 60 deletions(-)
diff --git a/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino b/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino
index ea340980a42..98f33290d9a 100644
--- a/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino
+++ b/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino
@@ -34,17 +34,16 @@
// Global copy of slave
esp_now_peer_info_t slave;
-#define CHANNEL 1
-#define PRINTSCANRESULTS 0
-#define DELETEBEFOREPAIR 0
+bool slaveFound;
+#define PRINT_ALL_SCAN_RESULTS 0
+#define DELETE_PEER_BEFORE_PAIRING 0
// Init ESP Now with fallback
void InitESPNow() {
WiFi.disconnect();
if (esp_now_init() == ESP_OK) {
Serial.println("ESPNow Init Success");
- }
- else {
+ } else {
Serial.println("ESPNow Init Failed");
// Retry InitESPNow, add a counte and then restart?
// InitESPNow();
@@ -57,53 +56,59 @@ void InitESPNow() {
void ScanForSlave() {
int8_t scanResults = WiFi.scanNetworks();
// reset on each scan
- bool slaveFound = 0;
+ slaveFound = false;
memset(&slave, 0, sizeof(slave));
Serial.println("");
if (scanResults == 0) {
Serial.println("No WiFi devices in AP Mode found");
} else {
- Serial.print("Found "); Serial.print(scanResults); Serial.println(" devices ");
- for (int i = 0; i < scanResults; ++i) {
- // Print SSID and RSSI for each device found
- String SSID = WiFi.SSID(i);
- int32_t RSSI = WiFi.RSSI(i);
- String BSSIDstr = WiFi.BSSIDstr(i);
-
- if (PRINTSCANRESULTS) {
- Serial.print(i + 1);
+ if (PRINT_ALL_SCAN_RESULTS) {
+ Serial.print("Found "); Serial.print(scanResults); Serial.println(" devices ");
+ for (int i = 0; i < scanResults; ++i) {
+ // Print SSID and RSSI for each device found
+ String SSID = WiFi.SSID(i);
+ int32_t RSSI = WiFi.RSSI(i);
+ String BSSIDstr = WiFi.BSSIDstr(i);
+ Serial.print(i);
Serial.print(": ");
Serial.print(SSID);
Serial.print(" (");
Serial.print(RSSI);
Serial.print(")");
Serial.println("");
- }
- delay(10);
+ } // for - loop through scanResults
+ } // if PRINT_ALL_SCAN_RESULTS
+
+ for (int i = 0; i < scanResults; ++i) {
+ // Print SSID and RSSI for each device found
+ String SSID = WiFi.SSID(i);
+ int32_t RSSI = WiFi.RSSI(i);
+ String BSSIDstr = WiFi.BSSIDstr(i);
+
// Check if the current device starts with `Slave`
if (SSID.indexOf("Slave") == 0) {
// SSID of interest
- Serial.println("Found a Slave.");
- Serial.print(i + 1); Serial.print(": "); Serial.print(SSID); Serial.print(" ["); Serial.print(BSSIDstr); Serial.print("]"); Serial.print(" ("); Serial.print(RSSI); Serial.print(")"); Serial.println("");
+ Serial.print("Found a Slave: "); Serial.print(i); Serial.print(": "); Serial.print(SSID);
+ Serial.print(" ["); Serial.print(BSSIDstr); Serial.print("]");
+ Serial.print(" ("); Serial.print(RSSI); Serial.print(")"); Serial.println("");
// Get BSSID => Mac Address of the Slave
- int mac[6];
- if ( 6 == sscanf(BSSIDstr.c_str(), "%x:%x:%x:%x:%x:%x", &mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5] ) ) {
- for (int ii = 0; ii < 6; ++ii ) {
- slave.peer_addr[ii] = (uint8_t) mac[ii];
- }
+ uint8_t mac[6];
+ if (6 == sscanf(BSSIDstr.c_str(), "%x:%x:%x:%x:%x:%x", &mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5] ) ) {
+ Serial.printf("Adding peer with MAC [%02x:%02x:%02x:%02x:%02x:%02x]\n", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+ memcpy(slave.peer_addr, mac, 6);
}
- slave.channel = CHANNEL; // pick a channel
- slave.encrypt = 0; // no encryption
+ slave.channel = 0; // 0 = Use whatever channel the Slave (AP) is using
+ slave.encrypt = false; // no encryption
- slaveFound = 1;
+ slaveFound = true;
// we are planning to have only one slave in this example;
// Hence, break after we find one, to be a bit efficient
break;
- }
- }
- }
+ } // if SSID starts with "Slave"
+ } // for - loop in scanResults
+ } // scanResults > 0
if (slaveFound) {
Serial.println("Slave Found, processing..");
@@ -118,15 +123,14 @@ void ScanForSlave() {
// Check if the slave is already paired with the master.
// If not, pair the slave with master
bool manageSlave() {
- if (slave.channel == CHANNEL) {
- if (DELETEBEFOREPAIR) {
+ if (slaveFound) {
+ if (DELETE_PEER_BEFORE_PAIRING) {
deletePeer();
}
Serial.print("Slave Status: ");
// check if the peer exists
- bool exists = esp_now_is_peer_exist(slave.peer_addr);
- if ( exists) {
+ if (esp_now_is_peer_exist(slave.peer_addr)) {
// Slave already paired.
Serial.println("Already Paired");
return true;
@@ -140,23 +144,18 @@ bool manageSlave() {
} else if (addStatus == ESP_ERR_ESPNOW_NOT_INIT) {
// How did we get so far!!
Serial.println("ESPNOW Not Init");
- return false;
} else if (addStatus == ESP_ERR_ESPNOW_ARG) {
Serial.println("Invalid Argument");
- return false;
} else if (addStatus == ESP_ERR_ESPNOW_FULL) {
Serial.println("Peer list full");
- return false;
} else if (addStatus == ESP_ERR_ESPNOW_NO_MEM) {
Serial.println("Out of memory");
- return false;
} else if (addStatus == ESP_ERR_ESPNOW_EXIST) {
Serial.println("Peer Exists");
- return true;
} else {
- Serial.println("Not sure what happened");
- return false;
+ Serial.println("Undefined Error");
}
+ return false;
}
} else {
// No slave found to process
@@ -183,16 +182,19 @@ void deletePeer() {
}
}
-uint8_t data = 0;
// send data
void sendData() {
- data++;
+ static uint8_t data = 0;
const uint8_t *peer_addr = slave.peer_addr;
- Serial.print("Sending: "); Serial.println(data);
+ char peer_addr_str[18];
+ snprintf(peer_addr_str, sizeof(peer_addr_str), "%02x:%02x:%02x:%02x:%02x:%02x",
+ peer_addr[0], peer_addr[1], peer_addr[2], peer_addr[3], peer_addr[4], peer_addr[5]);
+ Serial.print("Sending: "); Serial.print(data); Serial.print(" to addr: "); Serial.println(peer_addr_str);
esp_err_t result = esp_now_send(peer_addr, &data, sizeof(data));
- Serial.print("Send Status: ");
+ Serial.print("Send Status code= "); Serial.print(result); Serial.print(": ");
if (result == ESP_OK) {
Serial.println("Success");
+ data++;
} else if (result == ESP_ERR_ESPNOW_NOT_INIT) {
// How did we get so far!!
Serial.println("ESPNOW not Init.");
@@ -209,13 +211,13 @@ void sendData() {
}
}
-// callback when data is sent from Master to Slave
+// Callback when data is sent from Master to Slave
void OnDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) {
char macStr[18];
snprintf(macStr, sizeof(macStr), "%02x:%02x:%02x:%02x:%02x:%02x",
mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
Serial.print("Last Packet Sent to: "); Serial.println(macStr);
- Serial.print("Last Packet Send Status: "); Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
+ Serial.print("Last Packet Send Status code="); Serial.print(status); Serial.print(" : "); Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
}
void setup() {
@@ -235,13 +237,10 @@ void setup() {
void loop() {
// In the loop we scan for slave
ScanForSlave();
- // If Slave is found, it would be populate in `slave` variable
- // We will check if `slave` is defined and then we proceed further
- if (slave.channel == CHANNEL) { // check if slave channel is defined
- // `slave` is defined
+ // Check if slave was found
+ if (slaveFound) {
// Add slave as peer if it has not been added already
- bool isPaired = manageSlave();
- if (isPaired) {
+ if(manageSlave()){
// pair success or already paired
// Send data to device
sendData();
@@ -250,10 +249,6 @@ void loop() {
Serial.println("Slave pair failed!");
}
}
- else {
- // No slave found to process
- }
-
// wait for 3seconds to run the logic again
delay(3000);
}
diff --git a/libraries/ESP32/examples/ESPNow/Basic/Slave/Slave.ino b/libraries/ESP32/examples/ESPNow/Basic/Slave/Slave.ino
index d9029e961e3..e61499ca6e2 100644
--- a/libraries/ESP32/examples/ESPNow/Basic/Slave/Slave.ino
+++ b/libraries/ESP32/examples/ESPNow/Basic/Slave/Slave.ino
@@ -32,7 +32,6 @@
#include <esp_now.h>
#include <WiFi.h>
-#define CHANNEL 1
// Init ESP Now with fallback
void InitESPNow() {
@@ -52,7 +51,7 @@ void InitESPNow() {
// config AP SSID
void configDeviceAP() {
const char *SSID = "Slave_1";
- bool result = WiFi.softAP(SSID, "Slave_1_Password", CHANNEL, 0);
+ bool result = WiFi.softAP(SSID, "Slave_1_Password");
if (!result) {
Serial.println("AP Config failed.");
} else {
@@ -87,5 +86,5 @@ void OnDataRecv(const uint8_t *mac_addr, const uint8_t *data, int data_len) {
}
void loop() {
- // Chill
+ // Behavior is handled in callback function
}
From fe3ea447d5e34677fa16671ffc712400295ea829 Mon Sep 17 00:00:00 2001
From: Tomas Pilny <tomas.pilny@espressif.com>
Date: Wed, 24 Aug 2022 15:22:36 +0200
Subject: [PATCH 2/4] Revert "Removed option to change CHANNEL"
This reverts commit b2ec27de1d2d4703a15f6397550a46896413828a.
---
.../examples/ESPNow/Basic/Master/Master.ino | 109 +++++++++---------
.../examples/ESPNow/Basic/Slave/Slave.ino | 5 +-
2 files changed, 60 insertions(+), 54 deletions(-)
diff --git a/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino b/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino
index 98f33290d9a..ea340980a42 100644
--- a/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino
+++ b/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino
@@ -34,16 +34,17 @@
// Global copy of slave
esp_now_peer_info_t slave;
-bool slaveFound;
-#define PRINT_ALL_SCAN_RESULTS 0
-#define DELETE_PEER_BEFORE_PAIRING 0
+#define CHANNEL 1
+#define PRINTSCANRESULTS 0
+#define DELETEBEFOREPAIR 0
// Init ESP Now with fallback
void InitESPNow() {
WiFi.disconnect();
if (esp_now_init() == ESP_OK) {
Serial.println("ESPNow Init Success");
- } else {
+ }
+ else {
Serial.println("ESPNow Init Failed");
// Retry InitESPNow, add a counte and then restart?
// InitESPNow();
@@ -56,59 +57,53 @@ void InitESPNow() {
void ScanForSlave() {
int8_t scanResults = WiFi.scanNetworks();
// reset on each scan
- slaveFound = false;
+ bool slaveFound = 0;
memset(&slave, 0, sizeof(slave));
Serial.println("");
if (scanResults == 0) {
Serial.println("No WiFi devices in AP Mode found");
} else {
- if (PRINT_ALL_SCAN_RESULTS) {
- Serial.print("Found "); Serial.print(scanResults); Serial.println(" devices ");
- for (int i = 0; i < scanResults; ++i) {
- // Print SSID and RSSI for each device found
- String SSID = WiFi.SSID(i);
- int32_t RSSI = WiFi.RSSI(i);
- String BSSIDstr = WiFi.BSSIDstr(i);
- Serial.print(i);
- Serial.print(": ");
- Serial.print(SSID);
- Serial.print(" (");
- Serial.print(RSSI);
- Serial.print(")");
- Serial.println("");
- } // for - loop through scanResults
- } // if PRINT_ALL_SCAN_RESULTS
-
+ Serial.print("Found "); Serial.print(scanResults); Serial.println(" devices ");
for (int i = 0; i < scanResults; ++i) {
// Print SSID and RSSI for each device found
String SSID = WiFi.SSID(i);
int32_t RSSI = WiFi.RSSI(i);
String BSSIDstr = WiFi.BSSIDstr(i);
+ if (PRINTSCANRESULTS) {
+ Serial.print(i + 1);
+ Serial.print(": ");
+ Serial.print(SSID);
+ Serial.print(" (");
+ Serial.print(RSSI);
+ Serial.print(")");
+ Serial.println("");
+ }
+ delay(10);
// Check if the current device starts with `Slave`
if (SSID.indexOf("Slave") == 0) {
// SSID of interest
- Serial.print("Found a Slave: "); Serial.print(i); Serial.print(": "); Serial.print(SSID);
- Serial.print(" ["); Serial.print(BSSIDstr); Serial.print("]");
- Serial.print(" ("); Serial.print(RSSI); Serial.print(")"); Serial.println("");
+ Serial.println("Found a Slave.");
+ Serial.print(i + 1); Serial.print(": "); Serial.print(SSID); Serial.print(" ["); Serial.print(BSSIDstr); Serial.print("]"); Serial.print(" ("); Serial.print(RSSI); Serial.print(")"); Serial.println("");
// Get BSSID => Mac Address of the Slave
- uint8_t mac[6];
- if (6 == sscanf(BSSIDstr.c_str(), "%x:%x:%x:%x:%x:%x", &mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5] ) ) {
- Serial.printf("Adding peer with MAC [%02x:%02x:%02x:%02x:%02x:%02x]\n", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
- memcpy(slave.peer_addr, mac, 6);
+ int mac[6];
+ if ( 6 == sscanf(BSSIDstr.c_str(), "%x:%x:%x:%x:%x:%x", &mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5] ) ) {
+ for (int ii = 0; ii < 6; ++ii ) {
+ slave.peer_addr[ii] = (uint8_t) mac[ii];
+ }
}
- slave.channel = 0; // 0 = Use whatever channel the Slave (AP) is using
- slave.encrypt = false; // no encryption
+ slave.channel = CHANNEL; // pick a channel
+ slave.encrypt = 0; // no encryption
- slaveFound = true;
+ slaveFound = 1;
// we are planning to have only one slave in this example;
// Hence, break after we find one, to be a bit efficient
break;
- } // if SSID starts with "Slave"
- } // for - loop in scanResults
- } // scanResults > 0
+ }
+ }
+ }
if (slaveFound) {
Serial.println("Slave Found, processing..");
@@ -123,14 +118,15 @@ void ScanForSlave() {
// Check if the slave is already paired with the master.
// If not, pair the slave with master
bool manageSlave() {
- if (slaveFound) {
- if (DELETE_PEER_BEFORE_PAIRING) {
+ if (slave.channel == CHANNEL) {
+ if (DELETEBEFOREPAIR) {
deletePeer();
}
Serial.print("Slave Status: ");
// check if the peer exists
- if (esp_now_is_peer_exist(slave.peer_addr)) {
+ bool exists = esp_now_is_peer_exist(slave.peer_addr);
+ if ( exists) {
// Slave already paired.
Serial.println("Already Paired");
return true;
@@ -144,18 +140,23 @@ bool manageSlave() {
} else if (addStatus == ESP_ERR_ESPNOW_NOT_INIT) {
// How did we get so far!!
Serial.println("ESPNOW Not Init");
+ return false;
} else if (addStatus == ESP_ERR_ESPNOW_ARG) {
Serial.println("Invalid Argument");
+ return false;
} else if (addStatus == ESP_ERR_ESPNOW_FULL) {
Serial.println("Peer list full");
+ return false;
} else if (addStatus == ESP_ERR_ESPNOW_NO_MEM) {
Serial.println("Out of memory");
+ return false;
} else if (addStatus == ESP_ERR_ESPNOW_EXIST) {
Serial.println("Peer Exists");
+ return true;
} else {
- Serial.println("Undefined Error");
+ Serial.println("Not sure what happened");
+ return false;
}
- return false;
}
} else {
// No slave found to process
@@ -182,19 +183,16 @@ void deletePeer() {
}
}
+uint8_t data = 0;
// send data
void sendData() {
- static uint8_t data = 0;
+ data++;
const uint8_t *peer_addr = slave.peer_addr;
- char peer_addr_str[18];
- snprintf(peer_addr_str, sizeof(peer_addr_str), "%02x:%02x:%02x:%02x:%02x:%02x",
- peer_addr[0], peer_addr[1], peer_addr[2], peer_addr[3], peer_addr[4], peer_addr[5]);
- Serial.print("Sending: "); Serial.print(data); Serial.print(" to addr: "); Serial.println(peer_addr_str);
+ Serial.print("Sending: "); Serial.println(data);
esp_err_t result = esp_now_send(peer_addr, &data, sizeof(data));
- Serial.print("Send Status code= "); Serial.print(result); Serial.print(": ");
+ Serial.print("Send Status: ");
if (result == ESP_OK) {
Serial.println("Success");
- data++;
} else if (result == ESP_ERR_ESPNOW_NOT_INIT) {
// How did we get so far!!
Serial.println("ESPNOW not Init.");
@@ -211,13 +209,13 @@ void sendData() {
}
}
-// Callback when data is sent from Master to Slave
+// callback when data is sent from Master to Slave
void OnDataSent(const uint8_t *mac_addr, esp_now_send_status_t status) {
char macStr[18];
snprintf(macStr, sizeof(macStr), "%02x:%02x:%02x:%02x:%02x:%02x",
mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
Serial.print("Last Packet Sent to: "); Serial.println(macStr);
- Serial.print("Last Packet Send Status code="); Serial.print(status); Serial.print(" : "); Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
+ Serial.print("Last Packet Send Status: "); Serial.println(status == ESP_NOW_SEND_SUCCESS ? "Delivery Success" : "Delivery Fail");
}
void setup() {
@@ -237,10 +235,13 @@ void setup() {
void loop() {
// In the loop we scan for slave
ScanForSlave();
- // Check if slave was found
- if (slaveFound) {
+ // If Slave is found, it would be populate in `slave` variable
+ // We will check if `slave` is defined and then we proceed further
+ if (slave.channel == CHANNEL) { // check if slave channel is defined
+ // `slave` is defined
// Add slave as peer if it has not been added already
- if(manageSlave()){
+ bool isPaired = manageSlave();
+ if (isPaired) {
// pair success or already paired
// Send data to device
sendData();
@@ -249,6 +250,10 @@ void loop() {
Serial.println("Slave pair failed!");
}
}
+ else {
+ // No slave found to process
+ }
+
// wait for 3seconds to run the logic again
delay(3000);
}
diff --git a/libraries/ESP32/examples/ESPNow/Basic/Slave/Slave.ino b/libraries/ESP32/examples/ESPNow/Basic/Slave/Slave.ino
index e61499ca6e2..d9029e961e3 100644
--- a/libraries/ESP32/examples/ESPNow/Basic/Slave/Slave.ino
+++ b/libraries/ESP32/examples/ESPNow/Basic/Slave/Slave.ino
@@ -32,6 +32,7 @@
#include <esp_now.h>
#include <WiFi.h>
+#define CHANNEL 1
// Init ESP Now with fallback
void InitESPNow() {
@@ -51,7 +52,7 @@ void InitESPNow() {
// config AP SSID
void configDeviceAP() {
const char *SSID = "Slave_1";
- bool result = WiFi.softAP(SSID, "Slave_1_Password");
+ bool result = WiFi.softAP(SSID, "Slave_1_Password", CHANNEL, 0);
if (!result) {
Serial.println("AP Config failed.");
} else {
@@ -86,5 +87,5 @@ void OnDataRecv(const uint8_t *mac_addr, const uint8_t *data, int data_len) {
}
void loop() {
- // Behavior is handled in callback function
+ // Chill
}
From 06a9ca9b2a75e3909d9e13d3e3457a6fb265775c Mon Sep 17 00:00:00 2001
From: Tomas Pilny <tomas.pilny@espressif.com>
Date: Wed, 24 Aug 2022 15:40:53 +0200
Subject: [PATCH 3/4] Fixed the ability to change CHANNEL
---
libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino | 3 +++
libraries/ESP32/examples/ESPNow/Basic/Slave/Slave.ino | 1 +
2 files changed, 4 insertions(+)
diff --git a/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino b/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino
index ea340980a42..daa0eb3cd6d 100644
--- a/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino
+++ b/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino
@@ -31,6 +31,7 @@
#include <esp_now.h>
#include <WiFi.h>
+#include <esp_wifi.h> // only for esp_wifi_set_channel()
// Global copy of slave
esp_now_peer_info_t slave;
@@ -222,9 +223,11 @@ void setup() {
Serial.begin(115200);
//Set device in STA mode to begin with
WiFi.mode(WIFI_STA);
+ esp_wifi_set_channel(CHANNEL, WIFI_SECOND_CHAN_NONE);
Serial.println("ESPNow/Basic/Master Example");
// This is the mac address of the Master in Station Mode
Serial.print("STA MAC: "); Serial.println(WiFi.macAddress());
+ Serial.print("STA CHANNEL "); Serial.println(WiFi.channel());
// Init ESPNow with a fallback logic
InitESPNow();
// Once ESPNow is successfully Init, we will register for Send CB to
diff --git a/libraries/ESP32/examples/ESPNow/Basic/Slave/Slave.ino b/libraries/ESP32/examples/ESPNow/Basic/Slave/Slave.ino
index d9029e961e3..d2b5b09b10c 100644
--- a/libraries/ESP32/examples/ESPNow/Basic/Slave/Slave.ino
+++ b/libraries/ESP32/examples/ESPNow/Basic/Slave/Slave.ino
@@ -57,6 +57,7 @@ void configDeviceAP() {
Serial.println("AP Config failed.");
} else {
Serial.println("AP Config Success. Broadcasting with AP: " + String(SSID));
+ Serial.print("AP CHANNEL "); Serial.println(WiFi.channel());
}
}
From 38931d223dc68013af32c042f69079fe3fd384f9 Mon Sep 17 00:00:00 2001
From: Tomas Pilny <tomas.pilny@espressif.com>
Date: Fri, 26 Aug 2022 13:10:21 +0200
Subject: [PATCH 4/4] WiFi scan only on selected channel
---
libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino b/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino
index daa0eb3cd6d..b2e6b35506c 100644
--- a/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino
+++ b/libraries/ESP32/examples/ESPNow/Basic/Master/Master.ino
@@ -56,7 +56,7 @@ void InitESPNow() {
// Scan for slaves in AP mode
void ScanForSlave() {
- int8_t scanResults = WiFi.scanNetworks();
+ int16_t scanResults = WiFi.scanNetworks(false, false, false, 300, CHANNEL); // Scan only on one channel
// reset on each scan
bool slaveFound = 0;
memset(&slave, 0, sizeof(slave));