Are there any advantages to Wifi shields as opposed to a Yun?

Question

I have an Arduino Uno and I have a remote sensing project for which I need Wifi connectivity. After doing research, I've found that I have 2 options:

1. Buy a WiFi shield for my existing Uno
2. Buy an Arduino Yun with built-in WiFi

Looking at costs, I found that a WiFi shield costs more than double what it costs to buy a Yun, so it would seem to me that the best option is the Yun as I'd save some cash and get a more capable board. However, I can't help but think I'm missing something.

What are the advantages of an Uno plus Wifi shield as opposed to a Yun?

Answer 1

There's a number of things to consider that could sway your choice one way or another:

Power consumption

The Uno is a small low-power chip to which you add WiFi. The Yun is an Arduino Leonardo with a WiFi router (like you have on your desk) strapped to the back of it. The Yun will therefore consume considerably more power than the Uno.

Boot time

The Uno takes about 1 second to boot up - faster (instant) if you remove the bootloader and program it direct with a programmer. The Yun takes minutes to boot.

Stability

The Uno is a solid state single item. The Yun has an entire operating system with filesystems and things. It's far more likely that the Yun will corrupt itself through power loss than an Uno will get struck by a stray neutrino.

Cost

Yes, the Yun is cheaper. But is cheap always good?

Remote-ability

The Yun can be completely reprogrammed remotely. A new sketch can be uploaded to the Leonardo portion of it without you even having to be in the same country. The same can't be said for the Uno.

Power

The Linux portion of the Yun is considerably more powerful than any normal Arduino.

Answer 2

First of all yun is not the same as uno + wifi shield. yun is more like a linux pcc with wifi and a lenoardo.
If you are asking for your options there are more options. For what you want I would go for a ESP8266. Again there are 2 options here:

• uno + ESP8266 (as a wifi shield)
• ESP8266 (as a dev board)

I think it is pretty obvious that the ESP8266 (as a dev board) is the most cost effective.
You can program the ESP8266 just like a uno in the arduino IDE.
So I would advice to take that board.

Answer 3

There aren't just two options.

There are also Dragino and Iduino Yun shields, which are (usually) slightly cheaper than an Arduino Yun. These can be plugged into Leonardo/Uno base boards.

Whereas an Uno or Leonardo requires about 6-7v from the power supply, a Yun shield requires 9-12v (due to the Atheros chip drawing a bit extra).

There is also the Tian, which is the Yun's successor (but at higher cost).

If you're willing to look further afield than Arduino only, you might want to consider a BeagleBone Black (which works out slightly cheaper in terms of cost/feature).