Serial communication to Blynk

[Arikii]

Hi, i want to ask is it possible to use serial communication from arduino uno to nodemcu(esp8266) and then upload it to Blynk from nodemcu?

[Bill_Donnelly]

Yes, but why not just run your sketch on your Nodemcu? Why do you need the Arduino Uno?

[PeteKnight]

It is possible, but very difficult to achieve because of timing issues.

You’d probably be better running the code directly on the NodeMCU and doing away with the Uno, or using an ESP32 if you need more pins or more analog inputs.

Alternatively, you could look at Blynk MCP

Pete.

[Arikii]

Because when I connect ultrasonic sensor to nodemcu, the readings is not accurate and not consistent. But when I connect it to Arduino Uno, the reading is just fine.

[PeteKnight]

@Arikii

when I connect ultrasonic sensor to nodemcu, the readings is not accurate and not consisten

Ultrasonic sensors work fine with the NodeMCU. It’s probably something to do with your code, your choice of pins, or the way that you’ve powered the sensor - but it’s impossible to say which without more info.

Pete.

[distans]

@PeteKnight

It is possible, but very difficult to achieve because of timing issues.

In my ye olde project from 2017 I had to do something similar to be able to constantly listen for (after? to? Help me out here Pete, you know I’m from Sweden! ) 433 Mhz radio signals/data bursts.

Basically, I sent data from one UNO (the “radio slave”) to another UNO (the one with Blynk stuff) which has a RX buffer, and then checked for new data once every second. No timing issues there… or am I missing something?

The ye olde project:

Cheap(est) RF 433 Mhz bridge for home automation with both Tx and Rx

As so many other fellow Blynkers, I too want my home to be a little bit smarter than my neighbors. From the beginning I just wanted a scheduler to turn on/off my remote controlled power sockets, but during the process it evolved to also include a receiver. I can now control my sockets with both the physical remote and Blynk seamlessly – AND get the correct status in my phone. But implementing a super regenerative receiver wasn’t without its problem due to its “no signal noise” characteristics …

[PeteKnight]

@distans

or am I missing something?

Of course not, but Blynk newbies could easily get in a mess waiting for serial data and omitting to service the Blynk library with a Blynk.run() command.

Your “ye olde project” is also a bit of an overkill as far as hardware is concerned though.
I still use 433MHz quite a bit, because we have some window blinds that operate on that frequency, and I also like to use 433MHz keyfobs and stand-alone pushbuttons because of their long battery life, range, and compact size.
I use a single Wemos D1 Mini with 433 Tx and Rx modules connected to it as my 433MHz bridge device. I don’t run Blynk on it, because its part o my Node-Red/MQTT setup, but it would work just fine with Blynk. This makes the whole thing smaller than one Uno, and I don’t have to worry about sending data from one device to another over serial comms.

Pete.

[distans]

@PeteKnight

Of course not, but Blynk newbies could easily get in a mess waiting for serial data and omitting to service the Blynk library with a Blynk.run() command.

Ah… THEM! But I get your point!

@PeteKnight

Your “ye olde project” is also a bit of an overkill as far as hardware is concerned though.

A proverb from an ye olde Englishman: " Whatever is worth doing at all, is worth doing well " hehe

Don’t forget, I was a Blynk newbie myself at the time Starting with limited programming skills and exactly zero experience working with MCU’s, I’m quite happy how my project turned out!

I still like 433 MHz gadgets. It’s simple, it’s cheap, it’s easy to integrate. And no, I wouldn’t use an UNO today.