The default Hello World program, used when you create a new program

Dependencies:   mbed

Dependents:   stateScript dc_motor mbed_blinkylook ElektronikerSchnupperlehreAufgabe1

Update mbed library from revision 29 to revision 109

mbed library version is four years old - needs updating

Cpu Talk / HelloWorld Featured
Blink an LED - embedded version of HelloWorld ARM, blink led, Blinky, Flash LED, Flasher, hello world, helloworld, LPC1768, mbed, mbed_blinky, Nucleo, Nucleo_blink_led, ST, stm32


12 Nov 2015

Hello, what is new in this session.? I do not understand from Version 29 to 129 ? regards Bernd

12 Nov 2015

Bernd, in short, only the library version.

The long explanation: When you choose to "import" this example code into your online compiler, it also imports the specific version of the "mbed" library that the code was ORIGINALLY compiled with.

In the case of this example, the "mbed" library is version 29, almost 4 years old! (see file mbed.bld)

That old "mbed" library version trips up a lot of new users who simply want to run their first helloworld.

The reason: Code to support most of the newer hardware platforms were only added to "mbed" AFTER revision 29 of the library.

Unfortunately, newcomers don't know or expect this. Their compile fails, and their "out of the box" experience is ruined.

So, my pull request is to simply update to the latest library version.

In fact, I would suggest to rather use mbed_blinky as your first helloworld compile - it's the same code, but the library is somehow (I don't know how) always kept up to date with the latest version of "mbed".

As a typical example, I use the ST Micro Nucleo-L152RE eval board. Support for that board was only added in revision 77 of the mbed library. So, attempting to compile this version of helloworld with any version of the mbed library below version 77 results in a compile error. In other words, if I download and compile it right now for my Nucleo-L152RE, the compile fails.

You can easily fix this in your online compiler by performing an "Update" on the mbed library, but, sadly, newcomers typically don't know this.

By the way, you can always see what the requested changes in a pull request is by looking under the heading "Changed In This Revision". In this case, you'll see it's the contents of the file "mbed.bld", which is the file that specifies what revision of the library.

For interest sake: here's the short log on the mbed library:

Does this answer your question?