6 years, 10 months ago.

C027 not working

Hello guys

we here at our company are desperately trying to get the C027 running. We have three boards (REV A) here and with each one the same exact scenario:

First time flashing goes right. I was able to send an SMS and to make an HTTP request (with another fresh board)

After first time flashing, nothing works. The device appears, but as soon as you try to copy a flash file on it, the system freezes. We have tried copying with Google Chrome, Finder and the Terminal.

We have also noticed, that the device disappears either after copying (normal), but also after a certain time passed doing nothing.

We're now stuck with three bricked C027s and we need them working asap!

System: Mac OSX 10.8.5

Mount string: /dev/disk1 on /Volumes/MBED (msdos, local, nodev, nosuid, synchronous, noowners)

Browser: current version of Google Chrome

Platform: mbed-C027 RevA


Question relating to:

The u-blox-C027 is a complete starter kit that allows quick prototyping of a variety of applications for the Internet of Things. The application board has a MAX-M8Q GPS/GNSS receiver and …
posted by Michael Ammann 27 Jan 2014

4 Answers

6 years, 9 months ago.

I also have the same issue.

I now have one brick and the other - I don't want to get in the same state.

What I have noticed is that on Linux I believe you have flashed the binary - as I see the LED flashing. However when the mbed appears as a mass storage device 'again' it does not show you the binary file that you just flashed. As if it never existed.

My current brick happened when I asked it to send some output over USB so I have confidence that my binary is running. I'm using Linux Mint Code I used is below:

ublox mbed c027 with flashing LED

// on rev A we reasign the signal to A0
 #undef  LED
 #define LED A0
Serial pc(USBTX, USBRX);
DigitalOut myled(LED); 

int main() {
    pc.printf("C027 Ublox Test... \n\r");
    while(1) {
        myled = !myled;
        pc.printf("Changing LED Light ... \n\r");

Ublox - how about some investigation into this - very poor show! :-( ...

Kind regards, Nicholas.

6 years, 10 months ago.

Before copying, you must set the c027 to receive new software. Maybe with long press with reset button. After copying, reset the device with short press and the software start to work.

Also maybe rebooting Mac or trying with Windows pc helps. USB has problems in the computer side when connecting and removing usb devices often.

6 years, 10 months ago.


thanks for the answer, but unfortunately no progress: - Reset Mac did not help - Using Windows 8 PC did not help - Pressing the button for long time did not help, either.

Windows 8 behaviour is even more strange than the Mac one: - The red LED is blinking for some time, sometimes the MBED folder appears, but then it disappears. It seems that Windows is trying multiple times to mount the folder. - After some time (2 min) it stops, without showing the MBED folder.

Any help appreciated!

6 years, 10 months ago.

To flash the application CPU (LPC1768) with your project follow these steps but use your own image (on REVA boards the LED1 is not present): http://mbed.org/users/ublox/notebook/u-blox-C027-Downloading/

If the CMSIS-DAP interface cpu (LPC11U35) is corrupted you can re-flash it by following these steps. http://mbed.org/users/ublox/notebook/ublox-C027-Update-CMSIS-DAP-Interface-Firmware/

few Questions: Have you powered the board with 7..17V with the barrel jack connector ?. Do you see a file fail.txt in the disk drive trying to load your image?


on your questions:

- Yes, we have 9V / 1A power supply connected.

- on fail.txt: The disk is un-mounted w/o copy, we cannot see the file.

1st link: we followed the guidelines, but no improvement.

2nd Link: Done that, see below. Improvement: On Mac, the MBED disk is now mounted reliable. When we copy the file, the red LED is not blinking. After some time, (time out?) the MBED disk is ejected. When un-pluging and connecting back, no changes in the disk. Windows PC testing is still ongoing....

Just FYI:

Listing after having copied the latest firmware: [vaillant 28] CRP DISABLD > ls -la total 96 drwxrwxrwx 1 vaillant staff 512 27 Jan 14:20 . drwxrwxrwt@ 6 root admin 204 27 Jan 14:16 .. -rwxrwxrwx 1 vaillant staff 4096 27 Jan 14:20 ._firmware.bin -rwxrwxrwx@ 1 vaillant staff 43880 27 Jan 14:20 firmware.bin

posted by Stefan Vaillant 27 Jan 2014