deadmbed

Table of Contents

  1. Before you start - Windows users
  2. Video Guide
  3. Start here
  4. Other Problems
  5. Restoring partition format

Is your mbed dead? Let's see if we can track down what's wrong and get you up and running again!

Follow these steps carefully and methodically, as it is easy to miss problems. We get very few problems that really do turn out to be hardware problems, so it is worth taking the time to check everything carefully!

Is your Recycle Bin full? some operating systems, macOS for one, and likely most versions of windows, don't really delete files when you hit "delete". Instead they move them to a "Recycle Bin" or "Trash". This is normally a hidden folder. What this means for the average user is that you will eventually run out of space on the mbed.

Instead of just deleting a file, try right clicking and choosing "permanently delete" from the popup menu. If you already have a full recycle bin, try either emptying the recycle bin or changing your filemanager preferences to show hidden files, after which you may be able to delete your deleted files.

As people try this could they please report the steps they needed and their OS version in comments below.

Note

If you have a problem and track it down to something not covered here, or have any other tips, please extend this entry!

Before you start - Windows users

If you are using Windows, and are having problems copying files onto your mbed, try using a different USB cable. We have had a few reports of the cable causing a problem and have found that shorter cables, and cables with RF chokes (the molded cylinder you find on some cables) seem to work better. Also make sure you have installed the windows driver.

We are investigating the issue, and will update when we have more information.

Video Guide

Start here

Plug your mbed in to your computer using the USB cable, as described in the Setup Guide. What happens?

  1. The Status LED comes on, and the mbed disk drive appears
    • Sounds good. Move on to the next question!
  2. Nothing! Not even the Status LED comes on, and my computer doesn't see anything
    • Try a different USB port on your computer; the mbed needs a powered USB port, and maybe not all on your PC are powered
    • Try a different PC
    • Try a different USB cable; perhaps it is the USB cable that is defective.
    • If it is still dead and you've seen no life whatsoever, you should probably contact support@mbed.org to help get you running again...
  3. The Status LED comes on, but my computer doesn't see the mbed disk drive
    • Press and hold down the Reset Button and see if the drive appears; if the mbed is running a program that uses the mbed disk, it hides it from the PC. Holding the mbed in reset means the drive can appear.
    • Check the USB cable is plugged in fully to the mbed. It is possible for the connector to be in enough to provide power to the board, but not in far enough for the USB drive to be detected. This is especially true with new connectors, which can be stiff.
    • If you are using Windows and a drive hasn't appeared in ''My Computer'' after a few seconds, press F5, which forces a refresh. Often with explorer windows you need to hit F5 to refresh and display the mbed disk drive.
    • Sometimes a USB port can have data errors that stop it from working. Check for warning messages in Device Manager. If there is an issue, disable and re-enable that USB port.
    • It is possible that the D+/D- lines of the USB connector have become disconnected on the PCB, check the solder joints on these pins, this would disrupt communications but still shows power.

If it is still dead and you can't see the mbed disk drive, you should probably contact support@mbed.org to help get you running again...

Download a "Hello World" binary to the mbed, as described in Downloading a program. What happens?

  1. The Status LED flickers, and the file appears on the mbed disk drive (you can use your computer's file explorer to to check what is on the Microcontroller, as you would for a normal USB Disk)
    • Sounds good. Move on to the next question!
  2. The Status LED doesn't flicker at all.
    • Some Linux or old Macs don't write data until you "Eject" the drive; to make sure the data is written at once, see Mounting with sync
    • Make sure you save the file to the mbed disk drive; Some browsers default to saving files to your desktop or a downloads folder, so this should be changed; see these instructions on choosing where to save files
    • Make sure you didn't try and "Open" or "Run" the program files. Always "Save" them to the Microcontroller. Some applications (e.g. VLC Media Player) recognise the .bin extension; ignore them!
    • If you cant get a binary to copy on to the mbed disk, you should probably contact support@mbed.org to help get you running again...

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.

Press the reset button to load the Hello World program in to the microcontroller and start it running. What happens?

  1. The Status LED flashes as it is loaded, and the Hello World program runs!
    • Sounds like things are basically working; your problem is probably best directed at the forum
  2. The Status LED flashes the first time as it is loaded, but no program seems to run
    • Check the mbed disk is not too full; the file you saved to the mbed may not have been valid if there was not enough room to save it, so try deleting all the existing files from the drive and start the process again
    • Check you have compiled or run a binary for the correct target. Most people have the LPC1768 mbed, but there is also a LPC2368 version. Check you're matching the right binary with the right microcontroller.
    • Some Linux or old Macs don't write data until you "Eject" the drive; to make sure the data is written at once, see Mounting with sync
    • If you cant get a binary to copy on to the mbed disk, you should probably contact support@mbed.org to help get you running again...
  3. The Status LED goes off as I press the button, but I never see a brief flash on releasing the button.
    • The download will only happen on the first time a program is loaded. Try deleting everything of the mbed disk drive, unplugging it, and replugging it. Then download the Hello World binary and try again.
    • Some Linux or old Macs don't write data until you "Eject" the drive; to make sure the data is written at once, see Mounting with sync

Has your mbed ever worked?

  1. Yes. It has worked before.
    • Have you done anything to it that could have caused it to fail?
    • Try deleting everything off the mbed drive, and unplugging it, so you can start from a clean slate; go back to basics of running a hello world!
  2. No. I've never had it working.
    • Probably worth running through the basics or asking a friend to check it too. If that doesn't turn up anything, you should definitely contact support.

If you are still having problems, have a good search of the forums to check if anyone else has had the problem, and failing that contact us at support@mbed.org. Please include notes of what you tried and the results, and we'll be able to help you faster!

Other Problems

  • CRP Unbricking - Used CRP and now want your mbed back? Here's how to unbrick your mbed

Restoring partition format

- How to restore a USB drive to the original state
A USB drive has no partition and I created a partition...

Windows user: look at http://www.pendrivelinux.com/restoring-your-usb-key-partition, download Bootice.exe and follow the procedure (tested )

Linux User:
First we need to delete the old partitions that remain on the USB key.

  1. Open a terminal and type sudo su
  2. Type fdisk -l and note your USB drive letter.
  3. Type fdisk /dev/sdx (replacing x with your drive letter)
  4. Type d to proceed to delete a partition
  5. Type 1 to select the 1st partition and press enter
  6. Type d to proceed to delete another partition (fdisk should automatically select the second partition)
    Then format
    Type mkfs.vfat -F 12 -I -nMBED /dev/sdx (replacing x with your USB key drive letter)

Linux User: Safer method
There is an easier way to get the device (ie: /dev/sdx) on many modern systems

This method does not use a "root" console, but uses sudo for each command. This is considered to be safer as forgetting to "exit" from the root console does not lead to disaster. It also uses blkid to directly get the device path for the MBED.

First we need to delete the old partitions that remain on the USB key.

  1. Open a terminal and type the following commands 

sudo blkid -L MBED   # note your MBED device.
sudo fdisk /dev/sdx  #(replacing x with your drive letter)
  1. Type p to print the current partition table
  2. Type d to proceed to delete a partition
  3. Type 1 to select the 1st partition and press enter
  4. Repeat to delete all partitions as required Then format 

    sudo mkfs.vfat -F 12 -I -nMBED /dev/sdx   #(replacing x with your USB key drive letter)
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