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Hi all,

 

I think I always had the (wrong) impression that the pins on the booster pack are, at least attempted, to be standardized. Obviously this is not true. What I meant by standardized is that for example, the lower left pin is P2_2 on G2553 LP, but it is P4_1 on the new F5529 LP.

 

Looking at the design guide for booster pack at http://processors.wiki.ti.com/index.php/BYOB the "BoosterPack Pinout Standard" chart does not mention exact pin number. I always thought it is "standardized" by pin number but it looks like it is standardized by something else.

 

So, does that mean if one is using CCS or Energia, the program or library may need updating the pin number according to the target LP, unless strict coding practice are in place like using of abstracted variables like RED_LED are followed? How about common SPI / I2C library?

 

By the way, always wondered why the 40-pin layout is done the way it is now. Wouldn't it be more convenient if the extra 20 pins are laid "outside" rather than "inside" to the basic 20-pin settings? That way, we could have easier access to the extra pins when a 20-pin booster pack is in situ..

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Yeah since the platform is meant to support all of TI's MCU families (eventually, although the list is getting pretty complete now), they can't just assume the pin numbers are the same, especially since e.g. the Tiva uses letters for its ports instead of numbers, C2000 uses just general numbers, etc... so they're more or less standardized by position + function.

 

That said, keep in mind Energia's pin IDs should follow the boosterpack standard correctly; pin 1, 2, 3, 4 etc. should match the position in the boosterpack layout regardless of MCU.  However myself and many others tend to think of the pins in terms of port+bit and thus use PF_1, PF_2, P2_3, etc. in our sketches which is probably a bad thing.  Now that you mention this, I should think critically about changing my examples in Energia libs to use the straight numbers.

 

The MSP430G2 LaunchPad, being the very first, might not be "in line" with the new standard, which was obviously revamped when they realized the rest of the MCU families would be involved (I'm making some assumptions here, since I don't work for TI, but reasonable ones; internally I bet the LaunchPad project was a "crazy idea" that had to prove itself first for the rest of TI's MCU divisions to take it seriously, and once they did, this new "standardization" push for the 40-pin standard suddenly got on everyone's radar and the G2 LaunchPad may not have necessarily fit perfectly into that).

 

Valid point on the 40-pin LaunchPad standard, however, I am personally glad they chose to put the second row inside; the outer row of pins just barely fit inside 5cm, thus having the second row inside means that BoosterPacks supporting the XL standard still fit in the 5cm size often delineating different price structures for Chinese PCB fabs (like Elecrow, Seeed, ITead, etc).

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