Cannot run helloworld bin FAQ

Question:

My mbed Microcontroller doesn't work when I run the HelloWorld.bin from Downloading-a-program.

How should I go about finding the fault?

Answer:

Below are a series of steps to try. Please follow them carefully making notes as you go of what you tried, what you saw happen, and the outcome.

• Does the drive appear in your computer? - Make sure that the mbed Microcontroller appears as a USB disk. It should be writable, and have a capacity of 2MB. If it doesn't:
• Ensure that the USB connector is pushed in fully. See No-drive-appears-FAQ for more details.
• Use a different USB lead to connect the mbed Microcontroller to your PC.
• Plug the mbed Microcontroller into a different computer.
• If you have a second mbed Microcontroller available, try this too and see if this will appear correctly as a USB disk.

• Does the Status LED flash when you download HelloWorld.bin? - It should take a second or two for ''HelloWorld.bin'' to be transfered to your mbed Microcontroller. During this time, the Status LED should flash rapidly.

• Does the Status LED flash when program is transferred? - When the file has been saved to the USB disk, the first press of the Reset Button causes the program is loaded into the microcontroller. This takes a second or two, during which the Status LED flashes. Subsequent presses will simply cause the microcontroller to reset. The Status LED will be off while the button is pressed.

If the HelloWorld program doesn't work, try the following:

• Unplug the mbed Microcontroller and plug it back in, preferably to a different machine. Check that the HelloWorld.bin file still exists on the drive, and it is 53,372 bytes in size.

• Copy the HelloWorld.bin file from the board onto your PC. Confirm that the file copies correctly by checking that the copied file is 53,372 bytes.

• If you have a second mbed Microcontroller available, program it with the file that you have copied from the first microcontroller

If after following these instructions, you are still unable to run the HelloWorld program, please contact support@mbed.org