ESP8266 Community Forum

- Tue Apr 16, 2019 4:59 am #81824 Hi, i'm currently working on a project which requires me to send data from the MBED 'LPC1768' micrcontroller. I have correctly connected the interface between the LPC1768 and ESP8266 and found a useful code to establish a Wi-Fi connection, however, when I run this code I can't seem to get an IP address and so cannot connect the LPC1768 to the Wi-Fi. I was just wondering if anyone had any ideas?

Many thanks for any help!!


Code:

#include "mbed.h"

Serial pc(USBTX, USBRX);
Serial esp(P3.25, P3.26); // tx, rx
DigitalOut reset(p26);
Timer t;

int count,ended,timeout;
char buf[1024];
char snd[255];

char ssid[32] = "username"; // enter WiFi router ssid inside the quotes
char pwd [32] = "password"; // enter WiFi router password inside the quotes

void SendCMD(),getreply(),ESPconfig(),ESPsetbaudrate();


int main()
{
reset=0; //hardware reset for 8266
pc.baud(115200); // set what you want here depending on your terminal program speed
pc.printf("\f\n\r-------------ESP8266 Hardware Reset-------------\n\r");
wait(0.5);
reset=1;
timeout=2;
getreply();

esp.baud(115200); // change this to the new ESP8266 baudrate if it is changed at any time.

//ESPsetbaudrate(); //****************** include this routine to set a different ESP8266 baudrate ******************

ESPconfig(); //****************** include Config to set the ESP8266 configuration ***********************



// continuosly get AP list and IP
while(1) {
pc.printf("\n---------- Listing Acces Points ----------\r\n");
strcpy(snd, "AT+CWLAP\r\n");
SendCMD();
timeout=15;
getreply();
pc.printf(buf);
wait(2);
pc.printf("\n---------- Get IP and MAC ----------\r\n");
strcpy(snd, "AT+CIFSR\r\n");
SendCMD();
timeout=10;
getreply();
pc.printf(buf);
wait(2);
}

}

// Sets new ESP8266 baurate, change the esp.baud(xxxxx) to match your new setting once this has been executed
void ESPsetbaudrate()
{
strcpy(snd, "AT+CIOBAUD=115200\r\n"); // change the numeric value to the required baudrate
SendCMD();
}

// +++++++++++++++++++++++++++++++++ This is for ESP8266 config only, run this once to set up the ESP8266 +++++++++++++++
void ESPconfig()
{
wait(5);
strcpy(snd,"AT\r\n");
SendCMD();
wait(1);
strcpy(snd,"AT\r\n");
SendCMD();
wait(1);
strcpy(snd,"AT\r\n");
SendCMD();
timeout=1;
getreply();
wait(1);
pc.printf("\f---------- Starting ESP Config ----------\r\n\n");

pc.printf("---------- Reset & get Firmware ----------\r\n");
strcpy(snd,"AT+RST\r\n");
SendCMD();
timeout=5;
getreply();
pc.printf(buf);

wait(2);

pc.printf("\n---------- Get Version ----------\r\n");
strcpy(snd,"AT+GMR\r\n");
SendCMD();
timeout=4;
getreply();
pc.printf(buf);

wait(3);

// set CWMODE to 1=Station,2=AP,3=BOTH, default mode 1 (Station)
pc.printf("\n---------- Setting Mode ----------\r\n");
strcpy(snd, "AT+CWMODE=1\r\n");
SendCMD();
timeout=4;
getreply();
pc.printf(buf);

wait(2);

// set CIPMUX to 0=Single,1=Multi
pc.printf("\n---------- Setting Connection Mode ----------\r\n");
strcpy(snd, "AT+CIPMUX=1\r\n");
SendCMD();
timeout=4;
getreply();
pc.printf(buf);

wait(2);

pc.printf("\n---------- Listing Access Points ----------\r\n");
strcpy(snd, "AT+CWLAP\r\n");
SendCMD();
timeout=15;
getreply();
pc.printf(buf);

wait(2);

pc.printf("\n---------- Connecting to AP ----------\r\n");
pc.printf("ssid = %s pwd = %s\r\n",ssid,pwd);
strcpy(snd, "AT+CWJAP=\"");
strcat(snd, ssid);
strcat(snd, "\",\"");
strcat(snd, pwd);
strcat(snd, "\"\r\n");
SendCMD();
timeout=10;
getreply();
pc.printf(buf);

wait(5);

pc.printf("\n---------- Get IP's ----------\r\n");
strcpy(snd, "AT+CIFSR\r\n");
SendCMD();
timeout=3;
getreply();
pc.printf(buf);

wait(1);

pc.printf("\n---------- Get Connection Status ----------\r\n");
strcpy(snd, "AT+CIPSTATUS\r\n");
SendCMD();
timeout=5;
getreply();
pc.printf(buf);

pc.printf("\n\n\n If you get a valid (non zero) IP, ESP8266 has been set up.\r\n");
pc.printf(" Run this if you want to reconfig the ESP8266 at any time.\r\n");
pc.printf(" It saves the SSID and password settings internally\r\n");
wait(10);
}

void SendCMD()
{
esp.printf("%s", snd);
}

void getreply()
{
memset(buf, '\0', sizeof(buf));
t.start();
ended=0;
count=0;
while(!ended) {
if(esp.readable()) {
buf[count] = esp.getc();
count++;
}
if(t.read() > timeout) {
ended = 1;
t.stop();
t.reset();
}
}
}