programming esp-01 / communicate with nano

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1

Hi,

i got my fingers on some esp-01 modules and tried to programm them or let them communicatio with an nano.

problem is nothing works..
i wired up a breadboard to programm the esp directly for letting it connect to an Wlan or setting up an AP and delivering an single Webpage.
I've got an FTDI Converter (set to 3.3v) wired up like in the attached picture (10k resistor) and uploaded (esp was in programming mode) the AP Example of the Arduino IDE. Then a reset with 3.3v and GND, but nothing shown up in WiFi Listing.

Now i tried to let it communicate with an nano, wired itup like in the 2nd attachment (1k, and 2,2k Resistors) and tried this example code (replaced only ssid/pwd):

#include <SoftwareSerial.h>

char serialbuffer[1000];//serial buffer for request url
SoftwareSerial Serial1(0,1); // RX, TX

void setup()
{
  Serial1.begin(9600);//connection to ESP8266
  Serial.begin(9600); //serial debug
  
  //set mode needed for new boards
  Serial1.println("AT+RST");
  Serial1.println("AT+CWMODE=1");
  delay(500);//delay after mode change
  Serial1.println("AT+RST");
  
  //connect to wifi network
  Serial1.println("AT+CWJAP=\"SSID\",\"PWD\"");
}

void loop()
{
  //output everything from ESP8266 to the Arduino Micro Serial output
  while (Serial1.available() > 0) {
    Serial.write(Serial1.read());
  }
  
  if (Serial.available() > 0) {
     //read from serial until terminating character
     int len = Serial.readBytesUntil('\n', serialbuffer, sizeof(serialbuffer));
  
     //trim buffer to length of the actual message
     String message = String(serialbuffer).substring(0,len-1);
     Serial.println("message: " + message);
 
     //check to see if the incoming serial message is a url or an AT command
     if(message.substring(0,2)=="AT"){
       //make command request
       Serial.println("COMMAND REQUEST");
       Serial1.println(message); 
     }else{
      //make webrequest
       Serial.println("WEB REQUEST");
       WebRequest(message);
     }
  }
}

//web request needs to be sent without the http for now, https still needs some working
void WebRequest(String request){
 //find the dividing marker between domain and path
     int slash = request.indexOf('/');
     
     //grab the domain
     String domain;
     if(slash>0){  
       domain = request.substring(0,slash);
     }else{
       domain = request;
     }

     //get the path
     String path;
     if(slash>0){  
       path = request.substring(slash);   
     }else{
       path = "/";          
     }
     
     //output domain and path to verify
     Serial.println("domain: |" + domain + "|");
     Serial.println("path: |" + path + "|");     
     
     //create start command
     String startcommand = "AT+CIPSTART=\"TCP\",\"" + domain + "\", 80"; //443 is HTTPS, still to do
     
     Serial1.println(startcommand);
     Serial.println(startcommand);
     
     
     //test for a start error
     if(Serial1.find("Error")){
       Serial.println("error on start");
       return;
     }
     
     //create the request command
     String sendcommand = "GET http://"+ domain + path + " HTTP/1.0\r\n\r\n\r\n";//works for most cases
     
     Serial.print(sendcommand);
     
     //send 
     Serial1.print("AT+CIPSEND=");
     Serial1.println(sendcommand.length());
     
     //debug the command
     Serial.print("AT+CIPSEND=");
     Serial.println(sendcommand.length());
     
     //delay(5000);
     if(Serial1.find(">"))
     {
       Serial.println(">");
     }else {
       Serial1.println("AT+CIPCLOSE");
       Serial.println("connect timeout");
       delay(10000);
       return;
     }
     
     //Serial.print(getcommand);
     Serial1.print(sendcommand); 
}

now i should when i connect to the serial monitor and send "AT" get a "OK", but i get no response... i tried with 9600 and 115200 rate, with an original chip and an flashed one to 9600. the best thing i can get it crumpled output of what i send...

did i missed something in wiring or the code at programming or communication with the nano?

programm_esp_Steckplatine.png
programm_esp_Steckplatine.png921×957 67.8 KB

esp-01_to_nano.png
esp-01_to_nano.png1098×633 85.9 KB

2

My ESP would only work when powered by 3.3V from the arduino and no resistors on the tx & rx

The best way to get started is by loading the basic sketch and typing the commands in the serial monitor
remember - when using the serial monitor to send commands to it , wire it tx to tx and rx to rx
when you are ready to use it in a program, then tx to rx
also in the bottom right of monitor select "both NL and CR"

3

which esp do you use? an ESP-01?

which one do you mean by basic sketch?
you mean connecting the esp directly to the pc? or via the arduino? if over arduino, do you select the esp as board or the arduino as board?

may i ask why tx to tx in serial monitor and tx to rx in programm?
(i want to understand it, not just fixing :slight_smile: )