ESP8266-01S Stopped responding after second launch

Question

Here's the code:

#include <SoftwareSerial.h>
#define RX 6
#define TX 5
String AP = "...";
String PASS = "...";
SoftwareSerial esp8266(RX,TX); 
void setup() {
 Serial.begin(9600);
 Serial.println("Setup started");
 esp8266.begin(115200); // Change this to the factory baudrate used by ESP8266
 delay(1000);
 Serial.println("Setting BAUDRATE to 9600");
 esp8266.println("AT+IPR=9600");
 esp8266.begin(9600);
 delay(500);
 Serial.println("Setup finished");
 reset();
 connectWifi();
}
//reset the esp8266 module
void reset() {
 Serial.println("Resetting...");
 esp8266.println("AT+RST");
 delay(3000);
 if (esp8266.find("OK"))
 Serial.println("Module Reset");
 else
 Serial.println("Module Reset Failed!!!");
}
//connect to your wifi network
void connectWifi() {
 Serial.println("Connecting to Wifi...");
 String cmd = String("AT+CWJAP=\"") + AP + "\",\"" + PASS + "\"";
 esp8266.println(cmd);
 delay(4000);
 Serial.println("Checking Wifi...");
 int ctr=0;
 while(!(esp8266.find("OK"))) {
 if(esp8266.find("ERROR")) {
 Serial.println("Cannot connect to wifi...");
 break;
 }
 delay(50);
 ++ctr;
 if(ctr>10){
 Serial.println("Cannot connect to wifi...");
 break;
 }
 }
 Serial.println("ConnectWifi finished");
}

The ESP8266-01S wires are as follows:

1. GND to arduino ground
2. 3v3 to arduino 3v3
3. RX to arduino pin 5
4. TX to arduino pin 6
5. EN to arduino 3v3

The thing worked for one time, and when I re-compiled and sent it again without any changes or even button presses, it stopped working. Furthermore, if I connect ESP module directly through arduino rx and tx and connect arduino reset to ground, I still don't get anything. The led on the esp is blinking during data transfers, but everything else doesn't change and I get no response at all.

Answer 1

You need to re-flash your AI Thinker firmware. AT+IPR kills certain versions of the firmware.

Install the latest version of the firmware and use AT+UART_DEF=9600,8,1,0,0 and AT+UART=9600,8,1,0,0. (The former sets the default baud rate, the latter the current baud rate).

You can read more here.

• mcmikecreations: After resetting everything works through direct connection to PC, but when using a SoftwareSerial I get: Setting BAUDRATE to 9600 Response Received: Q⸮⸮E}⸮ʂb⸮b⸮,F⸮⸮⸮P%U⸮IT=N⸮⸮⸮L0 Qi⸮C!⸮CC⸮ ============ Command Sent: AT Response Received: ⸮⸮⸮⸮
• mcmikecreations: Here's my setup: void setup() { Serial.begin(9600); ESP8266.begin(115200); delay(1000); Serial.println("Setting BAUDRATE to 9600"); ESP8266.println("AT+UART_DEF=9600,8,1,0,0"); ESP8266.println("AT+UART=9600,8,1,0,0"); ESP8266.begin(9600); } `
• Majenko: Welcome to the wonderful world of dodgy at firmware. I would suggest you program the esp8266 to perform the task you require of it and not rely on the awful at firmware.