NXT serial number

[afanofosc]

I don't understand how changing the NXT's name within a running program has anything to do with an encryption program or showing the NXT's name in the menu system of a user-written program.

John Hansen

[mattallen37]

I don't understand how changing the NXT's name within a running program has anything to do with an encryption program or showing the NXT's name in the menu system of a user-written program.

John Hansen

Well, I don't want anyone to know how it could have to do with encryption, that is why I said so little about it. What I meant by the other part, is that I could run a program that takes like 500ms, and once the program has finished, I could see the result of whatever it was doing, by looking at the name of the NXT. The NXT name is one of the only user-defined things that is able to be viewed throughout almost all the menu, as well as any NXC program.

[afanofosc]

Okay, I understand now. A persistent bit of information that can be seen throughout the NXT's built-in menu system. I guess I could add a way to the enhanced firmware that will let you set the NXT's name.

John Hansen

[gloomyandy]

Hi,
The NXTs name is kind of interesting as it is one of the only things that will survive through a firmware update. The reason for this is that the data for the name is actually stored in the Bluecore module (which is the unit providing Bluetooth for the NXT), rather than in say the SAM7 flash memory. This raises the question of what sort of storage is used for holding the name and how many name changes it is rated for... Which may be something you want to think about before you start using it as some sort of general message store...

Andy

[mattallen37]

Exactly right. Adding that ability would be awesome.

[muntoo]

Hi,
This raises the question of what sort of storage is used for holding the name and how many name changes it is rated for... Which may be something you want to think about before you start using it as some sort of general message store...

So you're saying it's bad to change the NXT's name too many times?

[afanofosc]

I think he is only saying that it is not known whether frequently changing the name of your NXT will bring it to an early grave or not. Since it involves writing to some kind of persistent memory it might eventually "wear out" like the lock bits on the NXT flash memory which only last around ~7-8k cycles. That possibility is a reason to not go changing your NXTs name with great frequency.

John Hansen

[mattallen37]

I never thought about that aspect. I guess I'll just forget about it. Just curious, but has anyone ever "used up" their NXT by programming it enough times?

[gloomyandy]

I seem to remember seeing a post (which I think may have been from John) describing how someone deliberately cycled through a re-write sequence to see how many times it would work. I think the result was around 7000 times or so...

Andy

PS Oh and I don't know if the Bluecore module has a limit on the number of name changes, I was just suggesting that there could be a problem as I doubt if it would have been designed with the expectation that the name would get changed 1000's of times...

[schodet]

In mattallen37 case, it may be sufficient to change the name in IOMap, that is a hack anyway to display data in brick name.