WEMOS Mega +WiFi R3 ATmega2560+ESP8266

Hello everyone, I want to know (WEMOS Mega +WiFi R3 ATmega2560+ESP8266 (32Mb memory), USB-TTL CH340G. Compatible Mega, NodeMCU, WeMos ESP8266 ) can use with blynk ? Thank you for answer

@MAIL url for the product please?


Or You can find it from many stores. Thank you very much

@MAIL Search this forum for the keyword Robodyn… there is not much, but read through it and see if you have better results.

Don’t you just love a short url.


thank you Gunner

Perfect for Blynk.
I’m switching all my large applications to this board.
The only thing I had to change was the serial1 to serial3 for communications between esp and 2560


Hi, I am also interested in the wemos mega and see that you got it up and running.
I wondered witch code did you start from, judging from your comment on serial change i suspect the esp8266_shield code.
So after changing to serial3 al worked fine or where there other problems?
Thanks in advance!

yes, everything was fine after changing from serial1 to serial3
Good info here. http://www.sysengineering.ru/blog/электроника-контроллер-arduino-mega-с-esp8266/

@Danu_Itsnan_Habibi please edit your post (using the pencil icon at the bottom) and add triple backticks at the beginning and end of your code so that it displays correctly,
Triple backticks look like this:


The answer in my yt ch

Hi I’m new to Arduino
I would like to connect the same bord (mega2560+wifi integrated) with the relay module (16/32 relays) & control it through the Blynk server online& local. I know it’s simple automation but can’t find a proper guide or code over the Internet. Searched Google& YouTube for many hours with no success. Could you please suggest to me any step by step guide? Thank you for your help.

Hi, I watched your video I’m unable to understand.
Only you have videos on the topic on YouTube search for hours with no success.
Please make step by step guide with (mega2560+wifi & Blynk & relay 32 module) please add English.
Thank you.

Hey there.

I’ve never used this board before but I will try my best to help you.

So how can I help you buddy ?

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I just need to connect three things.

1- Arduino board, in this case, mega2560+wifi inbuilt ( mega2560 has more pinouts to control 32 channels relay module & particularly it has wifi builtin with saves me to add an esp8266 separately for wireless communication purpose)
2-Relay module (32 relay board its use for home automation)
3- Blynk ( I need to control all 32 relays with Blynk I’m only able to found 4 devices on Youtube. I like a paid plan from Blink with offline control like Blynk local server if lost Internet in case)

All three should work I need a code. ( I got all the hardware searched for many hours that why came here.)

Any help is highly appreciated.

Are you using blynk legacy or blynk 2.0 ?

Here are my thoughts…

(1) It’s very rare that you have a situation where the 32 devices you want to control are all in the same physical area. Usually, these devices are scattered around a large space, and in this situation its often better to have multiple devices with a smaller number of relays connected to them, in different locations around the building.
In my case, I control many individual devices with plug-in “Sonoff” type smart switches that are all controlled via Blynk. If you do indeed have 32 devices all wired back to one location then go with your initial plan.

  1. Using a singe 32-way relay board is generally not a great idea. If one relay fails then you have to remove the whole board and replace the entire board or the faulty relay. I find that it’s far better to use 4 or 8 relay boards instead, and have a few spare (and some replacement relays that you can use to repair a faulty board).

  2. Your choice of MCU board is awful! I wouldn’t accept one of these boards if someone gave me one for free. Far better to us a NodeMCU and two MCP23017 expansion boards instead, as described here…
    Using the MCP23017 IO Expansion Board

  3. If you want physical buttons to control each of the relays (often a good idea) then you’ll need 64 GPIO pins (so four MCP23017) and the Mega doesn’t have enough pins.

  4. Offline functionality isn’t currently available in Blynk IoT.

  5. Your Mega (or NodeMCU if you go down the MCP23017 route) counts as a single Blynk device.


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  1. Your absolutely right pete, in my opinion I will never ever use this board at all, instead I will use multiple esp32 or nodemcu.

  2. for the offline functionality it’s possible, I can use the app and a push button to control the device when it’s connected to the internet and the push button only when it’s not connected.


That’s not the same as the OP mentioned here…

and requires more GPIOs than is available with a Mega.


Yes, he needs a local server which is currently unavailable for blynk 2.0, but using the offline functionality in the sketch is also working perfectly.


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