Reverse channel for ESP_now

[SensorsIot]

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Hardware:

Board: ESP32 Dev Module
Core Installation/update date: 26/jul/2018 / Development release link: https://dl.espressif.com/dl/package_esp32_dev_index.json
IDE name: Arduino IDE 1.8.5
Flash Frequency: 80Mhz
Upload Speed: 921500

Description:

I have a working ESP_Now Scenario based on the example files. I use the CHANNEL 3 in the Master and CHANNEL 1 in the slave sketch as in the examples. When I try to send a message from the slave to the master I get this error:

Send Status: Peer not found.

I used the mac address from the master (ESPNow/Multi-Slave/Master Example STA MAC: 24:0A:C4:0D:4B:D8) as the peer_addr when I send a message from the slave to the master.

Sketch:

/**
/*
Robo Tank controller
Based on Slave example of ESP_now

Andreas Spiess (2018)

Attention: The telemetry channel from the controller to the remote does not work yet.

!!!!!!!!!!! Please use ArduinoJson Library 5.13, not 6.xx beta

*/

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

#define CHANNEL 1

unsigned long entry;
byte masterMAC[6];

// Init ESP Now with fallback
void InitESPNow() {
WiFi.disconnect();
if (esp_now_init() == ESP_OK) {
Serial.println("ESPNow Init Success");
}
else {
Serial.println("ESPNow Init Failed");
// Retry InitESPNow, add a counte and then restart?
// InitESPNow();
// or Simply Restart
ESP.restart();
}
}

// config AP SSID
void configDeviceAP() {
char* SSID = "Slave_1";
bool result = WiFi.softAP(SSID, "Slave_1_Password", CHANNEL, 0);
if (!result) {
Serial.println("AP Config failed.");
} else {
Serial.println("AP Config Success. Broadcasting with AP: " + String(SSID));
}
}

void sendData(byte *peer_addr) {
uint8_t commandJSON[COMMANDLENGTH];
StaticJsonBuffer jsonBuffer;
JsonObject& root = jsonBuffer.createObject();
root["battery"] = telemetry.batteryVoltage;
char jsonChar[COMMANDLENGTH];
root.printTo(jsonChar, COMMANDLENGTH);
root.printTo(Serial);
Serial.println();
memcpy(commandJSON, jsonChar, sizeof(jsonChar));
int JSONlen = 0;
while (commandJSON[JSONlen] != '}' && JSONlen < COMMANDLENGTH - 1) JSONlen++; // find end of JSON string
Serial.println(JSONlen);
esp_err_t result = esp_now_send(peer_addr, commandJSON, JSONlen + 1);
Serial.print("Send Status: ");
if (result == ESP_OK) {
Serial.println("Success");
} else if (result == ESP_ERR_ESPNOW_NOT_INIT) {
// How did we get so far!!
Serial.println("ESPNOW not Init.");
} else if (result == ESP_ERR_ESPNOW_ARG) {
Serial.println("Invalid Argument");
} else if (result == ESP_ERR_ESPNOW_INTERNAL) {
Serial.println("Internal Error");
} else if (result == ESP_ERR_ESPNOW_NO_MEM) {
Serial.println("ESP_ERR_ESPNOW_NO_MEM");
} else if (result == ESP_ERR_ESPNOW_NOT_FOUND) {
Serial.println("Peer not found.");
} else {
Serial.println("Not sure what happened");
}
delay(50);
}

// callback when data is recv from Master
void OnDataRecv(const uint8_t *mac_addr, const uint8_t *json, int data_len) {
char macStr[18];
StaticJsonBuffer jsonBuffer;
JsonObject& root = jsonBuffer.parseObject(json);
for (int i = 0; i < 6; i++) masterMAC[i] = mac_addr[i];

snprintf(macStr, sizeof(macStr), "%02x:%02x:%02x:%02x:%02x:%02x",
masterMAC[0], masterMAC[1], masterMAC[2], masterMAC[3], masterMAC[4], masterMAC[5]);
// Serial.print("Last Packet Recv from: ");
// Serial.println(macStr);

if (!root.success()) {
Serial.println("parseObject() failed");
} else {
int roboSpeed = root["speed"];
int roboAngle = root["angle"];
float roboBattery = root["battery"];
Serial.print(roboSpeed);
Serial.print(",");
Serial.println(roboAngle);
}
}

// callback when data is sent from Master to Slave
void OnDataSent(const uint8_t *mac_addr1, 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");
}

void setup() {
Serial.begin(115200);
Serial.println("ESPNow/Basic/Slave Example");
//Set device in AP mode to begin with
WiFi.mode(WIFI_AP);
// configure device AP mode
configDeviceAP();
// This is the mac address of the Slave in AP Mode
Serial.print("AP MAC: "); Serial.println(WiFi.softAPmacAddress());
// Init ESPNow with a fallback logic
InitESPNow();
// Once ESPNow is successfully Init, we will register for recv CB to
// get recv packer info.
esp_now_register_recv_cb(OnDataRecv);
}

void loop() {
if (millis() > entry + 1000) {
Serial.print("Sending ");
telemetry.batteryVoltage = 10.6;
for (int i = 0; i < 6; i++) Serial.println(masterMAC[i], HEX);

sendData(masterMAC);
entry = millis();
}

}

Debug Messages:

Sending
24
A
C4
D
4B
D8
{"battery":10.6}
15
Send Status: Peer not found.

Enable Core debug level: Debug on tools menu of Arduino IDE, then put the serial output here
ESPNow/Basic/Slave Example
[D][WiFiGeneric.cpp:345] _eventCallback(): Event: 0 - WIFI_READY
[D][WiFiGeneric.cpp:345] _eventCallback(): Event: 13 - AP_START
AP Config Success. Broadcasting with AP: Slave_1
AP MAC: 24:0A:C4:0D:81:E1
ESPNow Init Success

[lbernstone]

Duplicate of #1467

[everslick]

When posting code please use the correct markdown syntax (three ticks before and after the source).

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