# Properly flashing the firmware on a Lego Mindstorms NXT

I am attempting to upload a custom firmware to a Lego Mindstorms NXT and am having issues.

First of all, I'm attempting to use nxtOSEK, which would let me run C++ programs on it. The problem is, everytime I put it into firmware update mode, the download doesn't seem to actually occur.

What I mean by this is that, according to the output in my terminal (both Mac and Windows), the download was successful, however when the NXT reboots, I still see the normal logo (not nxtOSEK).

So, what I'm doing is first holding down the Reset button for a few seconds, then hitting the orange button, giving me that tic-tic-tic sound. Then I run the firmware update (either using the Windows NextTool or Mac OSX GUI NextTool) and attempt the download. I get a success message, yet the robot is still using the old firmware.

What could be the cause of this problem and how can I solve it?

• Have you tried downloading the firmware to a different NXT brick? – shea Oct 31 '12 at 6:54
• I have not, however this is a completely fresh unit.... – the_e Oct 31 '12 at 16:13
• Still, some NXT bricks are faulty when you get them. I've not used the nxtOSEK firmware before, but I'll try loading it onto my own brick and see what happens. – shea Oct 31 '12 at 21:26
• Ok thanks, I'll give that a shot the next time I'm in my lab. Fortunately we have more than one... – the_e Oct 31 '12 at 21:52
• I've just had a look at the nxtOSEK website... are you using the enhanced NBC/NXC firmware? (As in lejos-osek.sourceforge.net/howtoupload.htm#UploadToNXTfw and bricxcc.sourceforge.net/firmware.html) – shea Nov 1 '12 at 2:43

To check if the firmware installed properly, visit the Settings menu on the NXT, and then the NXT Version submenu. The top line should read: FW NBC/NXC x.xx, where x.xx is the version number of the firmware.