Arduino client hangs when trying to make a socket connection

I am working on a project that involves sockets in local network - I want to make a Java server (desktop application running on Windows) that will listen to and make connections with several clients - Arduino boards.

The problem is, code sticks while trying to make a connection. Here's the Java code:

monitorThread = new Thread(() -> {         try {             System.out.println("Creating socket...");             ServerSocket server = new ServerSocket(4444);             while (true) {                 System.out.println("Waiting for connection...");                 Socket client = server.accept();                 //NetworkManager.this.didConnect(client);                 System.out.println("Did establish connection");                 if (delegate != null) {                     delegate.didConnect(client);                 }             }         } catch (IOException exception) {             System.out.print(exception);         }     });     monitorThread.start(); 

and the Arduino code

#include <SPI.h> #include <Ethernet.h>  IPAddress serverIp(192, 168, 1, 101); int serverPort = 4444;  byte mac[] = {   0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xEF }; IPAddress ip(192, 168, 1, 178);  EthernetClient client;  void setup() {   Ethernet.begin(mac, ip);    Serial.begin(9600);   while (!Serial) {     ; // wait for serial port to connect. Needed for native USB port only   }    delay(1000);   // give the Ethernet shield a second to initialize:    Serial.println("connecting...");    if (client.connect(serverIp, serverPort)) {     Serial.println("connected.");   } else {     Serial.println("connection failed.");   } } 

What happens is both of those do not fail when trying to make a connection, but rather hang - Java server hangs on Socket client = server.accept();, but Arduino hangs as well - on client.connect(serverIp, serverPort)

Computer running Java server has a static IP (192.168.1.101).

I understand Java's server.accept() is a blocking call, so it will not proceed until a connection is made (what's why it runs in a separate thread), but what puzzles me is why Arduino hands as well.

Even if I try to connect to some other server IP and port - for example 64.233.187.99 (Google), it still hangs.

What am I doing wrong? Is there some additional setup that I haven't done? Can it have something to do with my network's settings?

1 Answers

Answers 1

Kindly try these steps and give it a try:

• Turn off firewall on Windows (Java Server)
• Check from another network connected pc that you can connect (telnet) to 192.168.1.101 on port 4444 (ie: telnet 192.168.1.101 4444)
• Change delay(1000) line to delay(5000) to give arduino ethernet shield more time to initialize

Also please post your loop code. I am using exactly the same code to communicate arduino to a java socket server. Your code seems fine; it might be firewall or something. Make sure you check out telnet connection from another machine.

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How to prevent Ajax overflow/server crash? (Arduino/ESP8266 Environment)

I have been recently learning how to program in Arduino to host an HTML/CSS/Javascript webpage on an Adafruit HUZZAH ESP8266 breakout, so please forgive me if my methods here are completely off.

I'm using Ajax to update a few pressure gauge values on a page and it works for a little while but eventually I just get ERR_CONNECTION_TIMED_OUT.

I get this all the time, especially when I'm just starting the server up. If I reset the wifi card enough times eventually it seems to load just fine but it's problematic and really unstable.

I've also noticed that it seems that the ESP8266 can only handle one user on it at a time, and once I try to connect from another computer/phone it crashes the server and I have to hit the reset button to get it working on that new host.

Can someone help me understand if I'm just using Ajax in a really inefficient way or why this is happening?

(Old Code removed to fit new code)

EDIT: So I believe I've improved my code in two ways:

• I've modified the hundreds of client.println() statements and instead stored the html/css/js content into four separate char arrays that are then printed out in only four client.println() statements.

• I've also reduced the number of ajax calls I had from five (not counting the two corresponding to the LED light that are still necessary) down to one by sending all of the variables at once within a comma delimited string that I then filter the corresponding variable content out of individually.

However, I am still experiencing frequent, yet random ERR_CONNECTION_TIMED_OUT errors, and I say random because I recently was able to successfully run the server with consecutive successful ajax calls for almost two hours before error messages began cropping up, and then immediately after restarting the server more error messages came up within only 30 seconds.

At this point I can't figure out if I am still using ajax inefficiently or if this is simply due to limitations of the ESP8266?

#include <ESP8266WiFi.h> #include <WiFiClient.h>  #include <Wire.h>  WiFiServer server(80); WiFiClient client; String HTTP_req; String req; double test = 42; String LEDstatus = "off";   (Some variable initializations removed for space)  char webpagePartOne[2500];  char webpagePartTwo[2500];   char webpagePartThree[2500];   char webpagePartFour[2500];   void switchLEDon() {  //Serial.println("TEST LED ON");  int ledStatusLength = 1;  subsys = 0x13;   //Account for the end of message messageLength = ledStatusLength + 2;  messageContent = 1;  Serial.write(som); Serial.write(messageLength); Serial.write(subsys); Serial.write(messageContent); Serial.write(eom); //Serial.println(""); //Serial.println("TURN LED ON|"); LEDstatus = "on"; } //end switchLEDon  void switchLEDoff() {      (almost the same as switchLEDon(), removed to lower char count here) } //end switchLEDoff  void setStatus(WiFiClient cl) {  currFluid += 22;  if(currFluid > 100) {     currFluid -= 100; }  cl.print(currNumRefresh); cl.print(","); cl.print(currPressureC); cl.print(","); cl.print(currPressureD); cl.print(","); cl.print(currPressureE); cl.print(","); cl.print(currFluid); }  void setup() {   Serial.begin(115200);    pinMode(LED_PIN, OUTPUT); WiFi.begin(SSID, pass);  while (WiFi.status() != WL_CONNECTED)  { delay(500); Serial.print("."); } Serial.println(""); Serial.println("WiFi connected");  // Start the server server.begin(); Serial.println("Server started");  Serial.println(WiFi.localIP()); }  void loop() {   //Communication Protocol if(Serial.available() > 0) {     //Serial.print("SERIAL.AVAILABLE: ");     //Serial.println(Serial.available());      //delay(1000);      if(initialCounter == 0)     {         rx_byte = Serial.read();     /*         //Print Start of Message         Serial.print("0x");         if(rx_byte<0x10)         {             Serial.print("0");         }         Serial.println(rx_byte, HEX);     */         //Serial.println(rx_byte, BIN);         //Serial.println(rx_byte);          initialCounter++;     }       if((!messageBegun) && (rx_byte == som))     {         messageBegun = true;          //Serial.println("MESSAGE BEGUN TRUE");     } //end if (messageInProgress && rx_byte)      if((messageBegun) && (!messageInProgress))     {         serialCurrent = Serial.available();          if(serialCurrent > 0)         {                   receivedMessageLength = (uint8_t)Serial.read();         /*             Serial.print("MESSAGE LENGTH: ");             Serial.println(receivedMessageLength);         */             messageBegun = false;              messageInProgress = true;              //Serial.println("MESSAGE IN PROGRESS TRUE");          } //end if (serialCurrent)     } //end if (messageBegun && messageInProgress)      if(messageInProgress)     {         serialCurrent = Serial.available();           if(serialCurrent >= receivedMessageLength)         {              Serial.readBytes(rxBuff, receivedMessageLength);              if((byte)rxBuff[receivedMessageLength-1] != eom)             {                 //Serial.println("ERROR");                 //Serial.write(Serial.read());             } //end if (rxBuff != eom)              else             {                 messageInProgress = false;                   for(int i=0; i<receivedMessageLength; i++)                 {                     if(rxBuff[i] == eom)                     {                     /*                         //Print End of Message                         Serial.print("0x");                         if(rx_byte<0x10)                         {                             Serial.print("0");                         }                         Serial.println(rxBuff[i], HEX);                     */                         initialCounter = 0;                          receivedMessageLength = 0;                      } //end if                      else if(i == 0)                     {                         receivedSubsys = rxBuff[i];                      /*                         //Print Subsystem                         Serial.print("0x");                         if(rx_byte<0x10)                         {                             Serial.print("0");                         }                         Serial.println(rxBuff[i], HEX);                     */                     } //end if                     else                     {                         if(receivedSubsys == 0x14)                         {                             currNumRefresh = rxBuff[i];                         } //end if                          else if(receivedSubsys == 0x15)                         {                             currPressureC = rxBuff[i];                         } //end else if                          else if(receivedSubsys == 0x16)                         {                             currPressureD = rxBuff[i];                         } //end else if                          else if(receivedSubsys == 0x17)                         {                             currPressureE = rxBuff[i];                         } //end else if                      } //end else                 } //end for              } //end else          } //end if (serialCurrent)      } //end if (messageInProgress) } //end if (Serial.available)  WiFiClient client = server.available(); if (client) {      boolean currentLineIsBlank = true;     String currentLine = "";     /*     if(digitalRead(LED_PIN))     {         LEDstatus = "on";     }     else if(!digitalRead(LED_PIN))     {         LEDstatus = "off";     }     */     while (client.connected()) {         if (client.available()) {              char c = client.read();             HTTP_req += c;              if (c == '\n' && currentLineIsBlank)              {                 client.println("HTTP/1.1 200 OK");                 client.println("Content-Type: text/html");                 client.println("Connection: keep-alive");                 client.println();                  //LED Functions                 if (HTTP_req.indexOf("ajax_LED_switch_on") > -1) {                     switchLEDon();                 }                 else if(HTTP_req.indexOf("ajax_LED_switch_off") > -1) {                     switchLEDoff();                 }                 else if(HTTP_req.indexOf("ajax_set_status") > -1) {                     setStatus(client);                 }                  else {                  //Part One                      strcpy(webpagePartOne,"<!DOCTYPE html>\n");                      strcat(webpagePartOne,"<html>\n");                         strcat(webpagePartOne,"<head>\n");                         strcat(webpagePartOne,"<title>Adafruit HUZZAH ESP8266</title>\n");                         strcat(webpagePartOne,"<style type='text/css'>\n");                              (css here removed for space)                          //Part Two                              (Some more css here removed for space)                          strcat(webpagePartTwo,"</style>\n");                         strcat(webpagePartTwo,"<script>\n");                              strcat(webpagePartTwo,"var currPressureTest = 0;\n");                             strcat(webpagePartTwo,"var currFluidTest = 0;\n");                              //Set Status function                             strcat(webpagePartTwo,"function setStatus(){\n");                                  strcat(webpagePartTwo,"nocache = \"&nocache=\"+ Math.random() * 1000000;\n");                                 strcat(webpagePartTwo,"var request = new XMLHttpRequest();\n");                                 strcat(webpagePartTwo,"request.onreadystatechange = function() {\n");                                     strcat(webpagePartTwo,"if (this.readyState == 4) {\n");                                         strcat(webpagePartTwo,"if (this.status == 200) {\n");                                             strcat(webpagePartTwo,"if (this.responseText != null) {\n");                                                  strcat(webpagePartTwo,"var totalStatus = this.responseText;\n");                                                  strcat(webpagePartTwo,"var splitStatus = totalStatus.split(',');\n");                                                  //strcat(webpagePartThree,"alert('Pressure C: ' + splitStatus[0] + ', Pressure D: ' + splitStatus[1] + ', Pressure E: ' + splitStatus[2]);\n");                                                  //Num Refresh                                                 strcat(webpagePartTwo,"document.getElementById(\"demo\").innerHTML = splitStatus[0];\n");                                                  //PRESSURE C                                                 strcat(webpagePartTwo,"var pressureValue = document.querySelector('.gauge-c');\n");                                                 strcat(webpagePartTwo,"pressureValue.style.transform = 'rotate('+ splitStatus[1] +'deg)';\n");                                                  strcat(webpagePartTwo,"var pressureText = (((splitStatus[1])/180)*100).toFixed(0);\n");                                                 strcat(webpagePartTwo,"document.getElementById(\"pressurePercentC\").innerHTML = pressureText + '%';\n");                                                  strcat(webpagePartTwo,"if(pressureText > 75){\n");                                                     strcat(webpagePartTwo,"pressureValue.style.background = 'red';\n");                                                    strcat(webpagePartTwo,"}\n");                                                  strcat(webpagePartTwo,"else if(pressureText > 25 && pressureText < 75){\n");                                                     strcat(webpagePartTwo,"pressureValue.style.background = 'yellow';\n");                                                  strcat(webpagePartTwo,"}\n");                                                  strcat(webpagePartTwo,"else if(pressureText < 25){\n");                                                     strcat(webpagePartTwo,"pressureValue.style.background = 'green';\n");                                                 strcat(webpagePartTwo,"}\n");                                                                              //PRESSURE D                                                 strcat(webpagePartTwo,"var pressureValue = document.querySelector('.gauge-d');\n");                                                 strcat(webpagePartTwo,"pressureValue.style.transform = 'rotate('+ splitStatus[2] +'deg)';\n");                                                  strcat(webpagePartTwo,"var pressureText = (((splitStatus[2])/180)*100).toFixed(0);\n");                                                 strcat(webpagePartTwo,"document.getElementById(\"pressurePercentD\").innerHTML = pressureText + '%';\n");                                                  strcat(webpagePartTwo,"if(pressureText > 75){\n");                                                     strcat(webpagePartTwo,"pressureValue.style.background = 'red';\n");                                                    strcat(webpagePartTwo,"}\n");                                                  strcat(webpagePartTwo,"else if(pressureText > 25 && pressureText < 75){\n");                                                     strcat(webpagePartTwo,"pressureValue.style.background = 'yellow';\n");                                                  strcat(webpagePartTwo,"}\n");                                                  strcat(webpagePartTwo,"else if(pressureText < 25){\n");                                                     strcat(webpagePartTwo,"pressureValue.style.background = 'green';\n");                                                 strcat(webpagePartTwo,"}\n");                                                   //PRESSURE E                                                 strcat(webpagePartTwo,"var pressureValue = document.querySelector('.gauge-e');\n");                                                 strcat(webpagePartTwo,"pressureValue.style.transform = 'rotate('+ splitStatus[3] +'deg)';\n");                                                  strcat(webpagePartTwo,"var pressureText = (((splitStatus[3])/180)*100).toFixed(0);\n");                                                 strcat(webpagePartTwo,"document.getElementById(\"pressurePercentE\").innerHTML = pressureText + '%';\n");                                              //Part Three                                                  strcpy(webpagePartThree,"if(pressureText > 75){\n");                                                     strcat(webpagePartThree,"pressureValue.style.background = 'red';\n");                                                    strcat(webpagePartThree,"}\n");                                                  strcat(webpagePartThree,"else if(pressureText > 25 && pressureText < 75){\n");                                                     strcat(webpagePartThree,"pressureValue.style.background = 'yellow';\n");                                                  strcat(webpagePartThree,"}\n");                                                  strcat(webpagePartThree,"else if(pressureText < 25){\n");                                                     strcat(webpagePartThree,"pressureValue.style.background = 'green';\n");                                                 strcat(webpagePartThree,"}\n");                                                   //FLUID LEVEL                                                 strcat(webpagePartThree,"var fluidValue = document.querySelector('.fluidMeter');\n");                                                 strcat(webpagePartThree,"fluidValue.value = splitStatus[4];\n");                                                  strcat(webpagePartThree,"var fluidText = splitStatus[4];\n");                                                 strcat(webpagePartThree,"document.getElementById(\"fluidPercent\").innerHTML = fluidText + '%';\n");                                  strcat(webpagePartThree,"}}}}\n");                                 strcat(webpagePartThree,"request.open(\"GET\", \"ajax_set_status\" + nocache, true);\n");                                 strcat(webpagePartThree,"request.send(null);\n");                                  strcat(webpagePartThree,"setTimeout('setStatus()', 5000);\n");                              strcat(webpagePartThree,"}\n");                              strcat(webpagePartThree,"function LEDswitch(){\n");                                 strcat(webpagePartThree,"var LEDswitchCheck = document.getElementById('myonoffswitch').checked;\n");                                  strcat(webpagePartThree,"if(LEDswitchCheck){\n");                                     strcat(webpagePartThree,"nocache = \"&nocache=\"+ Math.random() * 1000000;\n");                                     strcat(webpagePartThree,"var request = new XMLHttpRequest();\n");                                     strcat(webpagePartThree,"request.onreadystatechange = function() {\n");                                         strcat(webpagePartThree,"if (this.readyState == 4) {\n");                                             strcat(webpagePartThree,"if (this.status == 200) {\n");                                                 strcat(webpagePartThree,"if (this.responseText != null) {\n");                                                     //strcat(webpagePartThree,"document.getElementById(\"LEDbtn\").innerHTML = this.responseText;\n");                                     strcat(webpagePartThree,"}}}}\n");                                     strcat(webpagePartThree,"request.open(\"GET\", \"ajax_LED_switch_on\" + nocache, true);\n");                                     strcat(webpagePartThree,"request.send(null);\n");                                 strcat(webpagePartThree,"}\n");                                 strcat(webpagePartThree,"else if(!LEDswitchCheck) {\n");                                     strcat(webpagePartThree,"nocache = \"&nocache=\"+ Math.random() * 1000000;\n");                                     strcat(webpagePartThree,"var request = new XMLHttpRequest();\n");                                     strcat(webpagePartThree,"request.onreadystatechange = function() {\n");                                         strcat(webpagePartThree,"if (this.readyState == 4) {\n");                                             strcat(webpagePartThree,"if (this.status == 200) {\n");                                                 strcat(webpagePartThree,"if (this.responseText != null) {\n");                                                     //strcat(webpagePartThree,"document.getElementById(\"LEDbtn\").innerHTML = this.responseText;\n");                                     strcat(webpagePartThree,"}}}}\n");                                     strcat(webpagePartThree,"request.open(\"GET\", \"ajax_LED_switch_off\" + nocache, true);\n");                                     strcat(webpagePartThree,"request.send(null);\n");                                 strcat(webpagePartThree,"}\n");                             strcat(webpagePartThree,"}\n");                         strcat(webpagePartThree,"</script>\n");                      strcat(webpagePartThree,"</head>\n");                     strcat(webpagePartThree,"<body style='background-color:#558C89;' onload=\"setStatus();\">\n");                          strcat(webpagePartThree,"<div style='background-color:#74AFAD;'>\n");                             strcat(webpagePartThree,"<h1 style='text-decoration: underline;'>Adafruit HUZZAH ESP8266</h1>\n");                         strcat(webpagePartThree,"</div>\n");                         strcat(webpagePartThree,"<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0, user-scalable=yes\">\n</div>\n<div style=\"clear:both;\"></div><p>\n");                       strcat(webpagePartThree,"<div style='background-color:#74AFAD;'>\n");                             strcat(webpagePartThree,"<h2 style='color: red;'>LED Controls</h2>\n");                              strcat(webpagePartThree,"<div id='LEDbtn' class='onoffswitch'>\n");                                  /*                                 if (LEDstatus == "on")                                  {                                     strcat(webpagePartThree,"<input type='checkbox' name='onoffswitch' class='onoffswitch-checkbox' id='myonoffswitch' checked='checked' onclick='LEDswitch()'>\n");                                  } //end if                                 */                                 /*                                 else if(LEDstatus == "off")                                 {*/                                     strcat(webpagePartThree,"<input type='checkbox' name='onoffswitch' class='onoffswitch-checkbox' id='myonoffswitch' onclick='LEDswitch()'>\n");                                 //} //end else                                  strcat(webpagePartThree,"<label class='onoffswitch-label' for='myonoffswitch'>\n");                                     strcat(webpagePartThree,"<span class='onoffswitch-inner'></span>\n");                                     strcat(webpagePartThree,"<span class='onoffswitch-switch'></span>\n");                                 strcat(webpagePartThree,"</label>\n");                             strcat(webpagePartThree,"</div>\n");                         strcat(webpagePartThree,"</div>\n");                          //Part Four                          strcpy(webpagePartFour,"<div style='background-color:#74AFAD;'>\n");                             strcat(webpagePartFour,"<h2 style='color: green;'>Num Refresh Test</h2>\n");                             strcat(webpagePartFour,"<div id=\"demo\"><h2>Let AJAX change this text</h2></div>\n");                         strcat(webpagePartFour,"</div>\n");                     strcat(webpagePartFour,"</div>\n");                     //strcat(webpagePartFour,"<div id='gaugeCounter'></div>\n");                     strcat(webpagePartFour,"<div class='pressureRow'>\n");                         strcat(webpagePartFour,"<div class='pressureContainer'>\n");                             strcat(webpagePartFour,"<div class='gauge-a'></div>\n");                             strcat(webpagePartFour,"<div class='gauge-b'></div>\n");                             strcat(webpagePartFour,"<div class='gauge-c'></div>\n");                             strcat(webpagePartFour,"<div class='gauge-data'><h1 id='pressurePercentC'>0%</h1></div>\n");                         strcat(webpagePartFour,"</div>\n");                         strcat(webpagePartFour,"<div class='pressureContainer'>\n");                             strcat(webpagePartFour,"<div class='gauge-a'></div>\n");                             strcat(webpagePartFour,"<div class='gauge-b'></div>\n");                             strcat(webpagePartFour,"<div class='gauge-d'></div>\n");                             strcat(webpagePartFour,"<div class='gauge-data'><h1 id='pressurePercentD'>0%</h1></div>\n");                         strcat(webpagePartFour,"</div>\n");                         strcat(webpagePartFour,"<div class='pressureContainer'>\n");                             strcat(webpagePartFour,"<div class='gauge-a'></div>\n");                             strcat(webpagePartFour,"<div class='gauge-b'></div>\n");                             strcat(webpagePartFour,"<div class='gauge-e'></div>\n");                             strcat(webpagePartFour,"<div class='gauge-data'><h1 id='pressurePercentE'>0%</h1></div>\n");                         strcat(webpagePartFour,"</div>\n");                     strcat(webpagePartFour,"</div>\n");                      strcat(webpagePartFour,"<div class='fluidContainer'>\n");                         strcat(webpagePartFour,"<meter class='fluidMeter' max='100' value='50' low='25' high='75' optimum='100'></meter>\n");                          strcat(webpagePartFour,"<div class='fluid-data'><h1 id='fluidPercent'>0%</h1></div>\n");                     strcat(webpagePartFour,"</div>\n");                     strcat(webpagePartFour,"</body>\n");                     strcat(webpagePartFour,"</html>");                      client.print(webpagePartOne);                     client.print(webpagePartTwo);                     client.print(webpagePartThree);                     client.print(webpagePartFour);                 }              req = HTTP_req;                  //    Serial.print(HTTP_req);                 HTTP_req = "";                 break;             } //end if            }     }     delay(100);     client.stop(); } } 

4 Answers

Answers 1

I've also noticed that it seems that the ESP8266 can only handle one user on it at a time

What i suggest to do it to try and not to use the Keep-Alive header which might cause problems.

client.println("Connection: keep-alive"); 

When you set the Keep-alive its keeping the connection open all the time and this might cause the error.

If your server for example has a session timeout this should keep the session alive all the time.

The keep alive also has a timeout and maximum requests

Since you get this error every once in a while i assume that its a matter of your timeout + max requests that the server allow to accept on the keep alive connection.

Remove and test it without it.

Answers 2

try to use a packet sniffer Wireshark and screenshot the result

Answers 3

From: https://mcuoneclipse.com/2014/11/30/tutorial-web-server-with-the-esp8266-wifi-module/

Try closing the connection after you sent your repsonse:

Closing Connection: CIPCLOSE

So things are working:-). The trick is that I have to close the connection after I have sent the data. There is a CIPCLOSE command I can use:

AT+CIPCLOSE= which I can use to close a channel. So I close the connection with

AT+CIPCLOSE=0

Answers 4

So after a lot of testing I came to the conclusion that the ESP8266 cannot handle constant ajax updates and ended up using websockets to accomplish my task (which, thus far, appears to be FAR more stable than the ajax ever was).

Here's the example I based my result off of: https://gist.github.com/bbx10/667e3d4f5f2c0831d00b

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Arduino Clone CH340g osx issue (driver installed and apparently working)

I'd like to mention that the device I'm talking about in this question works fine using avrdude on a linux machine, the issue appears to be with the OSX driver for the CH340g

I've installed the latest CH34xx driver from www.wch.cn

The device appears to be recognised as /dev/tty.wchusbserial1420

I can connect to the device using avrdude and enter terminal mode, or try to upload, however working with the device seems very erratic.

When i enter terminal mode (using avrdude -t) the tx and rx lights flash indicating the device is connected and working, I get feedback from the UI

Reading | ################################################## | 100% 0.02s 

and if I type 'dump flash' or some command during the connection stage (while tx and rx are flashing) and hit enter as soon as the prompt appears, the command will execute, giving output like this:

avrdude> dump flash  0000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................| 0010  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................| 0020  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................| 0030  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................| 

however very shortly after the prompt appears, the 'L' light comes back on. From this point no command gives any output except

avrdude: ser_recv(): programmer is not responding avrdude: stk500_recv(): programmer is not responding 

This gives me the impression that something happens after avrdude connects, which is resetting the connection, and taking the device out of the avrdude: AVR device initialized and ready to accept instructions state.

I can't upload to the device for a similar looking reason, the output from attempting to upload is:

avrdude: Version 6.0.1, compiled on Apr 14 2015 at 16:30:25          Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/          Copyright (c) 2007-2009 Joerg Wunsch           System wide configuration file is "/Applications/Arduino.app/Contents/Java/hardware/tools/avr/etc/avrdude.conf"          User configuration file is "/Users/Ollie/.avrduderc"          User configuration file does not exist or is not a regular file, skipping           Using Port                    : /dev/tty.wchusbserial1420          Using Programmer              : arduino          AVR Part                      : ATmega328P          Chip Erase delay              : 9000 us          PAGEL                         : PD7          BS2                           : PC2          RESET disposition             : dedicated          RETRY pulse                   : SCK          serial program mode           : yes          parallel program mode         : yes          Timeout                       : 2000          StabDelay                     : 10          CmdexeDelay                   : 25          SyncLoops                     : 32          ByteDelay                     : 0          PollIndex                     : 3          PollValue                     : 0x53          Memory Detail                 :                                    Block Poll               Page                       Polled            Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack            ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------            eeprom        65     1     4    0 no       1024    4      0  3600  3600 0xff 0xff            flash         65     6   128    0 yes     32768  128    256    10    25 0xff 0xff            lfuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00            hfuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00            efuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00            lock           0     0     0    0 no          1    0      0  4500  4500 0x00 0x00            calibration    0     0     0    0 no          1    0      0     0     0 0x00 0x00            signature      0     0     0    0 no          3    0      0     0     0 0x00 0x00           Programmer Type : Arduino          Description     : Arduino          Hardware Version: 3          Firmware Version: 4.4          Vtarget         : 0.3 V          Varef           : 0.3 V          Oscillator      : 28.800 kHz          SCK period      : 3.3 us  avrdude: AVR device initialized and ready to accept instructions  Reading | ################################################## | 100% 0.02s  avrdude: Device signature = 0x1e950f avrdude: safemode: lfuse reads as 0 avrdude: safemode: hfuse reads as 0 avrdude: safemode: efuse reads as 0  avrdude: safemode: lfuse reads as 0 avrdude: safemode: hfuse reads as 0 avrdude: safemode: efuse reads as 0 avrdude: safemode: Fuses OK (H:00, E:00, L:00)  avrdude done.  Thank you. 

As you can see - the issue is not that the driver isn't installed or that avrdude can't see the device, but simply that the connection seems to die as soon as it is established.

I've been unable to find any reference to a similar error using google, and i've tried all the obvious stuff (re-installing drivers, different version of the driver etc)

1 Answers

Answers 1

You may have a hardware issue. On OSX it may not be resetting in a proper way, so bootloader not started and you receive "programmer is not responding" error. To fix you need improve your hardware by changing reset circuit. With CH340 reset is driven by RTS and DTR pins.

This also mean that you may try to look at your serial port settings and enable flow control.

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