Error downloading http://arduino.esp8266.com/stable …

Error downloading http://arduino.esp8266.com/stable/package_esp8266com_index.json

Is this the error you’re getting while trying to set up your Arduino IDE to use an esp8266? This can be pretty frustrating, because, after all – you just want to get started programming!

In this lesson we’ll show you exactly how to fix it – so you can get up and running with your esp8266.

esp8266 Core

The Arduino IDE is pretty awesome in many respects.

Not only can you use it to program and load code onto Arduino boards, you can also use it to program and load code on completely different boards and processors, like the widely popular esp8266 or the esp32. In order for the Arduino IDE to be able to work with the other boards, it needs what is called a “Core”.

Cores are necessary to make new microcontrollers compatible with your Arduino software.

The Arduino development team builds cores for its own boards, but anyone can develop a Core for their own boards.

And that’s what the esp8266 community generously did – they developed and maintain a core for the boards that use the esp8266 – which means you can set up your Arduino IDE to recognize and load code onto these boards.

All you have to do is tell the Arduino IDE where to get the core, and then use the Boards Manager tool to download it.

How to Download the esp8266 Core

The way you tell it is by pasting in a URL in Preferences > Additional Boards Manager.

The URL you paste in is:

https://arduino.esp8266.com/stable/package_esp8266com_index.json This comes right from the ESP8266 GitHub page.

Then you go to Tools > Board > Board Manager and … get an error – what’s

up?

Error downloading http://arduino.esp8266.com/stable/package_esp8266com_index.json

Why this error ? http://arduino.esp8266.com/stable…

So what’s going on? Basically what has happened, is that the Arduino IDE went to that URL to download the core, and when it got there, it couldn’t download the core.

Why not? Well, it could be that the esp8266 website is temporarily down. Sometimes that just happens.

But jeez, you were hoping to build your wifi cat feeder this afternoon, so waiting until the esp8266 website is back up, is a no go.

The Fix

Here is what you can do.  Use this URL instead:

https://github.com/esp8266/Arduino/releases/download/2.7.4/package_esp8266com_index.json

Or better yet, go to this webpage:
https://github.com/esp8266/Arduino/releases/

and look at what the current version is and then replace the 2.7.4 part with the newest current version number.

Save that, and restart the Arduino IDE.

Now when you go to the Tools > Board Manager you shouldn’t get that error, and you’ll be able to search for and install the esp8266 core, and see the different esp8266 boards, and you be on you way to building your IoT cat feeder.

Why did the error go away?

So what’s the difference between these two URLs? One is pointing to the esp8266 website, and the other is pointing to GitHub.

The first one will always have the most current stable version of the core. The second one points to a specific version of the core.

Like I mentioned, sometimes the esp8266 website can be down, which is why the first URL didn’t work.

Update Additional Board Managers

Now, in my opinion, it makes sense, that after you have downloaded the core, you should probably go back and update the Additional Board Managers URL to that first URL

http://arduino.esp8266.com/stable/package_esp8266com_index.json

This way, at a later date, if you ever go to update the esp8266 core, the Boards Manager will have the the most current version available for you.