Blynk ota update failed

I recently started using Blynk for a personal application.
The problem is that at first the firmware update (OTA) worked correctly, but now it doesn’t work anymore.
I don’t get a clear error, it just resets the MCU. In the console, after enabling BLYNK_DEBUG I have the following message:

[7640] <@[00|03|00|13]sys_ota[00]OTA started
[7681] Disconnected
[7682] Disconnected
[7683] Client not connected

ets Jan 8 2013,rst cause:2, boot mode:(3,6)

load 0x4010f000, len 3460, room 16
tail 4
chksum 0xcc
load 0x3fff20b8, len 40, room 4
tail 4
chksum 0xc9
csum 0xc9

The problem seems to occur at the following sequence in OTA.h

WiFiClient* clientTCP = new WiFiClient();
  if (!clientTCP->connect(host.c_str(), port)) {
    OTA_FATAL(F("Client not connected"));
  return clientTCP;

Any ideas on the reason for this problem?
I use esp8266 with 4Mb flash, Blynk @ 1.1.0, PlatformIo with Visual Code.

What does the Blynk.Air shipment log in the web console say?


Thanks for reply!
I don’t know if I’m looking in the right place, but I have this message.

I’m back with an update.
I made another device, the one I’m having problems with is already mounted outside and it’s harder to work on it.
I installed the exact same firmware using a USB-TTL interface and then tried to update over the air. It worked without problems.
It’s hard to figure out what the problem is.

Is the device that failed in a location where it’s getting a strong WiFi signal?
It might be worth adding-in some code to send the RSSI value to Blynk.


I also had the problem with the update in the location where it now works with test device.
I’ll try tomorrow to see if it’s a location issue and try to update the test device on location where is and production device.
Now I can’t because I have exceeded the maximum number of updates that can be made, probably in a day.
Interestingly, on the price page, I don’t see this limitation for a free account.


There are 2 different limits:

  • One limit is for the number of shipments you can create. For free plan - it’s 2 shipments. You can remove old shipments and create a new one. Shouldn’t be a problem
  • Another limit is the number of uploads (of firmware) you can do per day. Now it’s a 25 uploads per day on all plans. it’s not missing, but hard to see:

Thank you!
I understand now.
But still not see this https api limits on page with blynk plans.

Check the documentation

The plan comparison page obviously lists the high level features of each of the plans. The more in-depth limits are mostly outlined in the documentation.


Back to my problem.
I did a test in the morning with the test device placed in the location where the other device is also located. The update worked without problems on the test device, so it is not a problem related to the Wifi signal.

A post was split to a new topic: Problems with Blynk.Air

I had the exact same problem that was not solved…