I noticed my PC was not downloading programs to the LPC1768 when I compiled. Naturally it ran the last program loaded. Tried all the usual switch off etc. no change. I moved to my other PC and found I could load and run a program ok. I moved back to the original PC and found the LPC1768 was running a different program. I repeated the process to double check. So, on one computer it runs one program, on another PC it runs a different program without resetting etc. Any ideas?

Check the current date/time. LPC1768 relies on the file's timestamp to choose the most recent one, so if your PC sets wrong date it might pick something else.

Thanks for suggestion. Checked time and PC is about 20 sec from internet time. I notice that if I compile on the problem PC the status LED does not flash. It did on the other one. The reason I cannot use the other PC all the time is because it is old and slow. Type a character and it appears in HyperTerminal about 5 secs later!

Not sure if I should start a new topic for this. Still got problems. Can I 're-install' anything? I think USB communication is ok. PCB works on another PC (but too slow for everyday use). When the PCB is plugged into the one I want to use, the status LED flickers, suggesting communication is ok. Device shows as Com6 on device manager. Was using an early version of IE, so installed Google Chrome (as per the PC which worked) Didn't make any difference. Most significant problem appears to be that when compile is run, there is no change to status LED, so no program loading. The 'problem' of it running a different program on the other PC is probably just a symptom of whatever is wrong with it. Any ideas? Anybody? Anywhere? Please?

Hi Roger,

If the status light is not flashing when you download, that basically means it is not seeing any file transfer.

On the problem PC, can you try just deleting all the files from the mbed and hitting reset (nothing should run), then copy a binary from your desktop to the mbed and check the status light flashes as it transfers. A binary to try can be found at:

• http://mbed.org/nxp/lpc1768/

Take a look in explorer and check the files are appearing; unplug and replug to ensure it is not a caching issue; some older versions of windows cache USB disk files until you say "eject" or equivalent, so check if you need to do this.

Perhaps also try copying on a different binary and check it replaces it; main thing is to cut out anything to do with the browser.

Other things which are easy to forget when changing machines would be something like the downloaded file going to the wrong place (e.g. the download folder, rather than the mbed). The date aspect has already been mentioned which is a good one to check, but should only impact which binary is loaded, not whether you can store the binaries on the mbed.

If you are still having problems, you could try formatting the mbed drive and then power cycling it (unplug, replug), or even try a different USB port if it is something to do with the power available, but I suspect it is something to do with the copying process.

Simon

Dear Simon, thanks for your reply. Funnily enough there are some prog files on the desktop but I'm not sure when they got there. I noticed after I put Google Chrome on, it was saving things to the Download file. I assumed that the process of loading the code onto the device happened when the status light flickered and that the file saving was a later process and relevant only to saving changes to the programs. As I wasn't changing anything at the time it didn't bother me but maybe there was more significance than I realised. It'll take me a while to take in your info and to try it. Thanks. Roger

Oooooh yesss. It's alive. I haven't redirected the saving of the file to the drive yet but I imagine if I select the right path it should go back to it next time. Thank Simon. If I have any further probs I will let you know. Thanks again