Good day, I’m working on a project that involves two separate ESP32s where one will collect temperature data and send it to the other ESP32. The second esp32 will check the data and send it to Blynk. However, I can only establish consistently the handshake between the ESPs. The problem now is when uploading to Blynk where it either uploads to Blynk but the data does not update because the value received from the other ESP is not delivered successfully, or it does not connect to Blynk at all. I tried many troubleshoots already. I tried using different connectivity methods such as TCP/IP and ESP-NOW.

The simple solution is to make both ESP32s Blynk devices (each with its own unique Auth token) and have them send the data to Blynk independently.

Alternatively, the “slave” ESP32 could upload its data to the “master” device in Blynk using the Blynk HTTP(S) API


Are the two ESP32s communicating over LoRa? If so, I had an issue doing this and resolved it. Right now I have a “sender” and “receiver” ESP32. The “receiver” is also connected to WiFi and to Blynk and works fine.

@etnol said…


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Hello Jimmy, I haven’t tried using LoRa. Can you tell me how to implement it with my current plans for my project?

Hello Pete,

I’m a bit confused on why make both ESP32s Blynk devices if my plan is that the function of one ESP32 is just to be a sender only and the other one is a receiver while being connected to Blynk?

As I said, it’s the simple solution.

Blynk requires devices to perform regular handshakes with the server, and most devices can’t easily maintain communications using two different protocol stacks. The simple solution is not to attempt that, and have them just running the Blynk protocol and communicating directly with the Blynk server.

There are of course different ways to achieve what you want, and in my own home automation system all of my devices talk to a central “hub” device via MQTT messaging, then that hub device is the only one that talks to Blynk. But, this requires considerably more effort than the simple solution I suggested.

LoRa requires additional hardware, with a LoRa transmitter/receiver to handle the device to device communication.


One of the ESP32 could run Blynk.NCP, while the second one collect all the data and send it to the Blynk cloud.