• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 31 subscribers
  • Views 1143 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TM4C123 launchpad 0-ohm resistors - why are they still there?

Luis Afonso
Guru 20670 points

Back to the 0-ohm resistors that connect B7-PD1 and PB6-PD0. These ones (Amit at this point is "not another one of these" but I am sorry I want some answers if you please):



Okay then this is something that has been referred tons of times before but please allow me to revive this nuisance that for that same complaining has become a nuisance to the Tiva team and particularly Amit that has to hear this (justified) whining.

So well, I think from long ago hearing it was for compatibility with boosterpacks for the first launchpad, the MSP430G. Is this true?


If it is for boosterpack compatibility then why, for me to use the Educational boosterpack MKII to it's fullest, I require to remove those same resistors? I believe the boosterpack layout now is standardized correct? Then basically any boosterpack or combination of boosterpacks that require SPI and analog inputs from the launchpad can't be used with a unmodified TM4C123 launchpad - of course the standard has total of 8 analog pins but still, 2 are "useless" if SPI is used or vice versa.

I was testing the individual components of the boosterpack - I don't have it yet so that's how I test for now) - and I actually spent quite a while figuring it out why when I finally connected a acelerometer, all the SPI devices stopped working... I thought it was maybe not enough power supply for some reason and actually went out of my way to the lab get external 3.3V supply.


So Tiva team, please explain to me why this resistors exist in the first place.
And why they should still stay there? Why shouldn't there be a change? The MSP430G launchpad had how many version? I think it was 5 correct? For improvements!
I'm not asking (among some other users) for a change in the silicon like that NMI trap, this is a simple change - don't solder the resistors. If it's so important for that to exist sometimes then just jumpers and allow to be configurable by hand...


  • 0
    TI__Guru**** 244440 points
    Hello Luis

    You are correct. The addition of the Resistor was done in order to be compatible with the MSP430 BoosterPack Standard. And as it has been raised on the forum, it should have been easy to remove and install jumpers rather than 0402. However with the production program any such change at this point is not possible and it would be a ton of LP's before which a new header replacement would be possible. Not to mention that this will require change of the Mfg files and approval process that takes a lot of time.

    Regards
    Amit
  • 0 in reply to Amit Ashara
    Guru 20670 points
    Hi Amit,

    Thanks for the answer.

    I understand it would take time but it seems it should have already started to move towards that goal - wasn't the boosterpack standard already created?
    I would say that having the remove those resistors beats the points of the boosterpacks - no wire, no soldering, no breadboard - easy and quick to use.

    "it would be a ton of LP's before which a new header replacement"
    You are talking about many tiva launchpads, right? Not launchpads in general (or are there more that don't have the boosterpack standard?)


    I am not asking to start having different launchpads tomorrow or next week or something ridiculous like that. I am asking for the Tiva team to really consider to start the "movement" to change the launchpad and I brought the example of this boosterpack as "motivation" and reason to ask this.

    This particular boosterpack I referred is a educational boosterpack. Made to simplify. Yes I know it seems it's being more pushed to the MSP432 launchpad.



    Well I am ranting a little but I am not bashing on you Amit (maybe a bit on the TM4C123 current design).
    I don't want to have to remember to always remove those 2 resistors from every launchpad (and it as shown that I usually don't remember to)
  • 0 in reply to Luis Afonso
    Guru 117855 points

    Luis - is the answer not most clear?

    Simply - the comfort of the vendor exceeds the (likely) harmful effects - visited upon a large (and growing) percentage - of vendor's "user-client" base.