ESP8266 crashes receiving UDP Packets

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1

Hi, I have this code to receive UDP packets sent from my phone to the ESP8266:

#include <ESP8266WiFi.h>
#include <WiFiUdp.h>
#include <WiFiClient.h>

WiFiServer server(80);

//UDP
WiFiUDP Udp;
#define SERVER_PORT 80
char packetBuffer[] = ""; //buffer to hold incoming packet
int PACKET_MAX_SIZE = 24;
int packetSize;


void receiveUDP() {
	packetSize = Udp.parsePacket();
	if (packetSize) {
		Serial.print("Packetsize: ");
		Serial.println(packetSize);
		// read the packet into packetBufffer
		Udp.read(packetBuffer, PACKET_MAX_SIZE);
		Serial.println(packetBuffer);
		for (int i = 0; i < PACKET_MAX_SIZE; i++) {
			packetBuffer[i] = 0;
		}
	}
}


void openAP() {
	WiFi.softAP("NodeMCU");
	delay(1000);
	Serial.print("IP: ");
	Serial.println(WiFi.softAPIP());
}


void setup() {
	Serial.begin(115200);

	WiFi.mode(WIFI_AP);

	//Open Access Point
	openAP();

	Udp.begin(80);

	//server.begin();

}

void loop() {

	receiveUDP();

}

Now, when I send packets that are until 3 bytes long, everthing works ok. When I receive packets that are 4 bytes long, I start to receive these weird characters in the end of the packets. When I receive packets that are 5+ bytes long, the ESP8266 crashes and send the following error:

Packetsize: 1
1
Packetsize: 2
12
Packetsize: 3
123
Packetsize: 4
1234Єþ?
Packetsize: 5
12345„þ?
Packetsize: 5

Exception (9):
epc1=0x402018ec epc2=0x00000000 epc3=0x00000000 excvaddr=0x3ffe8465 depc=0x00000000

ctx: cont 
sp: 3ffef930 end: 3ffefb20 offset: 01a0

>>>stack>>>
3ffefad0:  3ffee950 3ffeeabc 3ffee948 402018e4  
3ffefae0:  00000000 00000000 00000016 3ffeeaf0  
3ffefaf0:  3fffdc20 00000000 3ffeeae8 40201920  
3ffefb00:  00000000 00000000 00000000 40202d9d  
3ffefb10:  00000000 00000000 3ffeeb00 40100114  
<<<stack<<<

 ets Jan  8 2013,rst cause:2, boot mode:(3,6)

load 0x4010f000, len 1264, room 16 
tail 0
chksum 0x42
csum 0x42
~ld
IP do Access Point: 192.168.4.1

Any one has got a clue on why the issue on 5 bytes UDP packets?

2

Your buffer defintion char packetBuffer[] = ""; //buffer to hold incoming packetis incorrect and only reserving one byte, try;

int PACKET_MAX_SIZE = 24;
char packetBuffer[PACKET_MAX_SIZE];     //buffer to hold incoming packet