Is this some hint for "UNO+esp8266 buffer-overflow" problem?

Dear Blynk engineers ,

I faced a problem using Arduino UNO and ESP8266 by HardSer.

esp8266 baud rate set to 4800 to prevent misreading. (happened before, but not in Blynk)

My code is below , and I just open the serial monitor , found these incoming messages(some incoming some echo i think.)

#include <ESP8266_HardSer.h>
#include <BlynkSimpleShieldEsp8266_HardSer.h>
ESP8266 wifi(Serial);
#include <Delay.h>   // this is some non-blocking timer library using millis()
int var_1 = 5;
NonBlockDelay object_1;
WidgetLCD object_2(4);
void setup()
Blynk.begin("auth", wifi, "ssid", "pswd");
while (Blynk.connect() == false){;};//Wait until connected;
void loop()
 if (object_1.Timeout() )
object_2.print(5-1, 2-1, "a=");
object_2.print(7-1, 2-1, analogRead(0 ));

when the first ASCII letter remain readible , my Blynk app functioned normal, but after some of the square box shows up (out of ASCII? or some misreading?) , Blynk seems send AT+CIPCLOSE command to ESP8266… causing the app says “UNO not connected” , and then the program spend several second to reconnect , about 5~10 second this happens again and again , spend 5~10 seconds connect – function for 5~10 seconds – disconnect – spends 5~10 seconds connect – function for … over and over

this problem might need to be handled… because ESP8266 standalone is not easy to do more “violent” things than ESP8266+arduino UNO … which i bet lots of people like me is trying to.

i set the baud to 115200 , more "square box"showed up but when the boxes showed up , blynk app still works fine(but still disconnect and reconnect itself) , Why would the Blynk lib. try to close connection when every thing is fine? is it reached the flooding limit? i read the LCD and a n analogPin value in my app widgets. , LCD writing runs per second.

the analog reading rate is 250ms (4 time per sec), i kept this ,but set the LCD to refresh every 3 seconds instead of 1 second , the disconnect-reconnect issue is gone…

@yonoodle I have the same (or very similar) problem with the same hardware as you. Technically I have Nano with ESP but the board selection is Uno becuase of the WDT bug in the Nano.

I’m not convinced the problem is with the odd looking characters as I seem to have the disconnects with out them. Only just started using LCD and it is very promising except this issue.

I have a temperature sensor that refreshes to the lcd every 10 or 15 seconds and this works fine. I have a button to send an RF signal from my arduino and this works fine. However when I use buttons to write single digits to the LCD is seems to regularly disconnect and reconnect the ESP.

I am not clearing the LCD as the room temperature remains top left of the LCD at all times (but only refreshes every 10 or 15 seconds). So the button presses are only adding a single character in the second row of the LCD. I can’t see how this is flooding the servers.

Maybe the developers can look into this.

@yonoodle I notice you have delays in your main loop. I have next to nothing in my loop (just Blynk, timer and WDT reset). Have you tried using a timer rather than the main loop? I will perhaps move WDT but I don’t think that is the problem because it was working fine until I added the LCD.


~ vw 6 p 2 1 3 [231245] Cmd not sent
[231510] Login timeout
disconnects and reconnects

Same with:
Ô vw 6 p 2 1 3 [190084] Cmd not sent

But I get Cmd not sent, disconect and reconnect even without the funny prefixed symbols.
Any idea what the problem is as LCD is currently unusable for me (and others)?

LCD works for me. What versions of app, libs do you use?

@Dmitriy I was wondering about all the recent Blynk changes. Blynk App was updated 24 hours ago but when my system boots it reports Blynk v0.3.1. I saw a Bynk notice about v0.3.3 being available for test. Should I be using v0.3.2?

I think it is always better to use latest version. But if current lib fully satisfy you - no need to update. Regarding latest version - it is better to take directly from trunk

Just tried v0.3.3-beta, the latest trunk I believe. It appears to have made things MUCH worse for the UNO with ESP8266. Locking up the ESP8266 regularly. Didn’t fix the problems with the LCD or the Timer Widget.

Looking at the releases I guess there wasn’t a v0.3.2.