@mohan_sundaram Why would anyone ride a bike when there are perfectly good cars, or own a dog when cats are superior 
and so on… Often it is all one knows about, has, or needs at the time.
There is nothing wrong with using Arduino and ESP… a bit of effort and understanding on the users part to connect and properly utilise, but the same can be said for many sensors, motors, displays, etc.
I agree and believe it is to do with familiarity. Am trying to understand in which usage/tech need scenarios that combo of Uno+ESP8266 would be preferred. Given that folks would be familiar with Arduino code and ESP8266/32 would run those with minor mods, I asked that question. Am looking to learn and not criticise a choice.
You are right, sorry for my assumption that you were following in others footsteps 
Well, even the lowly UNO has more I/O, particularly Analog in, then many ESP8266 dev boards. And the MEGA… well, mega more 
Many older sensors are still 5v and even 3.3v sensors work without any efforts on base Arduinos.
Many UNO compatible shields out there that can be used with Blynk
Even without using an ESP as shield, the lowly UNO can be used with Blynk (via USB) for non mobileised uses and still have room for a shield… all without taking up any otherwise elsewhere needed WiFi boards.
Bike v Car
Bike is much cheaper, better for your health but slower.
If you have a mega project to build a Mega might be useful but it will not be a true IOT project.
ESP v Arduino + nightmare dongle.
ESP is cheaper, faster, easier to use and allows you build IOT projects.
Chronic Fatigue = not safe to use bike for now (AKA, what works for some, will not work for all)
Bin dar dun dat… and IS true IoT as I can control everything on it over the internet and across the world
(assuming I ever leave the house first)
Two crossed wires, power & ground, NO soldering… even you can do it 
I had like 6 Arduinos and 0 ESPs when I started with Blynk, and yet I made IoT projects quickly, easily and NO new expense (aside from what I already had).
Round 2? 
@Costas I know you like yanking my chain on this… ditto here 
But honestly, I still use my Arduinos, and they still have purpose. Does that mean I am anti ESP…NOT A CHANCE… I fully intend to use them going forward. But this ongoing debate is about those who, like me, may not have a choice yet.
I fully intend to help those as they try… i just don’t want to keep repeating myself repeatedly each and every time… so I encourage them to search for the info, not bail out because of peer pressure.
An IOT project is one that adapts as technology changes i.e. WAN firmware updates etc.
If you want to build a fixed project at higher cost use an Arduino + nightmare dongle.
If you want to build a flexible IOT project use a low cost ESP.
If you want to learn, use what you have and focus on the challenge… if you want the easy way out, buy new and beg for assistance… see where that gets you
PS since when does Internet of Things mean you can’t use older technology… My 16Mhz MEGA is doing more simultaneous Blynk stuff then the average ESP-only project in this forum… and will even work on battery if I want it to 
Cost me $0 at the time I started Blynk… well… there was that time I purchased energy for my Local Server 
Blynk has just released an awesome new widget.
You have code on your Mega for me to flash new firmware, from here, to use this new widget?
No, that’s why IOT projects use ESP’s.
My dad uses a tractor to clean out his barn, not his 3/4 ton dually pickup… that he uses for the trailers… not his car… that he uses for going to town to pick up parts for the tractor 
Eanc of those is a vehicle of some sort and each has benefits/disadvantages over the others… doesn’t’ make one better than the other for a Farming of Land project… why should an MCU make/model/connection type matter to IoT 
It is NOT called IoESP
Hey, again!? An (already) ancient topic for discussion, but… why not? 
As for me, the answer is simply: Because I could to do so. A toy? Why not? Adults needs toys as well, especially adult boys Could I use the ESP in this particular project? Sure! But a Blynk was just an addition to already working toy (or “project” as I prefer to call it anyway)
Well, there is one that I’m aware. Interrupts and timers are sometimes very important in some specific tasks. And it seems the AVR processors are far better documented in this aspect then ESP. Not to mention it’s hardware capabilities. Can we use the only hardware timer of ESP8266 in Arduino IDE? If so, I don’t know how. The software PWM is a bit like software Serial port. It works, but it is not a real thing. That said, I still prefer using ESP’s in IOT things, but it doesn’t mean I gonna forget about AVR’s
And one more! Using Blynk in destinations, where no WiFi is available at all. Here comes the AVR + GSM combo. And it is very similar in many terms to AVR +ESP, but that is a different story.
Forget FOL, this is an IOT site.
@ashish_pandey what made you think adding an ESP to an Arduino would be a good idea? Does your project need an Arduino as the vast majority of projects don’t.
Some people like sticking pins in their eyes but it’s not really for me.
Me too.
Add GSM module to the ESP.
So… that’s a no to you writing that prefect farming code for me 
Oh well…
Actually I think my viewpoints put ‘pins’ in your eyes more then mine 
Sorry 
And me as well… I just also like using ALL of my stuff however I want to 
Heavens forbid… a nightmare dongle suggestion from @Costas … say it isn’t so 
Actually, I want to get a GSM module one of these days… but then there is the data fees, etc… and no real need, I just like learning new hardware
And what s creature is that? I wouldn’t do that. Or at least put a sticker on it: Build at your own risk.
Well, I try to protect my eyes the best I can, but there are many more holes… And why not? As a way to explore new territories… In IOT world?
@Costas You do know that while we both have our firm beliefs, all this is in fun 
But I think if we debate this on every new ESP & Arduino topic, perhaps new users will switch over BEFORE they dare ask directions for such
We should come up with a debate for all “Need Help Soonest” and “Give me code” requests 
All are talking just out of topic. I asked how can i connect my ESP8266 module to Arduino and Blynk 
And I asked:
You started with:
Developers spent a huge amount of time providing this information rather than developing the project.
Sorry, didn’t noticed that. But there are plenty of answers to this question. Just cross the Serial lines, and provide level conversion between. That’s more or less all you need. And of course the firmware to run on both. The AT firmware on ESP and your ‘sketch’ on Arduino.
Not really… just debating the issue of why ESP & Arduino. Your question has been answered hundreds of times actually all throughout this very forum.
And I gave you a solid answer… but if you can’t or won’t search… then you will find yourself with lots of problems in life.
We are here to help you learn about Blynk, not take your order and ask if you want fries with that, each and every time asked… when there’s a whole buffet right behind you, ready for the taking
Click on this topic from just a few days ago (about one of the key components of linking the two)… read to the end and click on the next topic link I included at the bottom, and the next, and so on