Mindboards

yes you're right! The FT controller uses it's ARM9 directly without any co-processor in between.

mightor wrote:The difference is that the FT controller probably uses hardware I2C and the NXT uses a bit-banged approach for the sensor ports. The hardware I2C on the ARM7 chip in the NXT is used to communicate with the ATmega. It was a design trade-off, I guess.

- Xander

What!? You mean, LEGO has faked us out!? Ungenuine protocol

To quote GLaDOS "No! NO! NO! AAAAAAAAAAAAAAA-"

Oh, that's nothing compared to what they did for the NXT 2.0 color sensor! They used their own custom, unique protocol for that!

And actually, SW I2C master in general does have it's advantages. You can setup whatever error codes you want, and you can instantly recover from any error. However, the NXT FW is awful about I2C errors. Most often the program crashes when it gets an error, instead of being allowed to deal with it.

However, the NXT FW is awful about I2C errors. Most often the program crashes when it gets an error, instead of being allowed to deal with it.

sounds as if you're talking about BT, not i2c ;)

Well, despite the NXT's shortcomings, it's actually very impressive and stable for a $150 toy.

mattallen37 wrote:Oh, that's nothing compared to what they did for the NXT 2.0 color sensor! They used their own custom, unique protocol for that!

I know! Infuriating, right?

mattallen37 wrote:And actually, SW I2C master in general does have it's advantages. You can setup whatever error codes you want, and you can instantly recover from any error. However, the NXT FW is awful about I2C errors. Most often the program crashes when it gets an error, instead of being allowed to deal with it.

Oh, I didn't know that. This business just sounds better and better....

mattallen37 wrote:Well, despite the NXT's shortcomings, it's actually very impressive and stable for a $150 toy.

Yes, but couldn't you build your own for much less than that?

If you understand the NXT's HW and SW limitations, then working with them to build custom sensors and interfaces isn't usually too hard.

inxt-generation wrote:

mattallen37 wrote:Well, despite the NXT's shortcomings, it's actually very impressive and stable for a $150 toy.

Yes, but couldn't you build your own for much less than that?

Well, it doesn't cost them that much to make them. If you think about it though, the FW is fairly stable, and the HW is almost bullet-proof. It would take a long time for an individual to come up with a comparable product at a comparable end-user price. And at that, there are many non-lego controller boards available (things like Arduino, Leaf Labs, Fez, Beagle Board, Olimex, etc.).

I've ordered a pressure sensor and a couple of segment LED displays from Digi-Key. Also, my TI LaunchPad came about a week ago. I plan to use one of the chips that come in this for the pneumatic thing. Currently compiling a list of other parts I'll probably need.

Oh, BTW, I just want to say that TI is AWESOME When I ordered my LaunchPad, I literally got it less than 24-hours later And it was supposed to be 2-day shipping. A fully featured development platform, plus UberFast shipping for $4.30. Not bad.

I have 5 of those Launchpads but I haven't really had much of a chance to play with them. I bought 5 because they were giving huge discounts. I think I got them all for the price of 2 or 3 in total. They are super low power.

- Xander