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Replacement of LM3S818 in Tiva C Series

aliasgar panahi
Prodigy 100 points
Other Parts Discussed in Thread: LM3S818, TM4C123GH6PM, DRV8301, LM3S811, TM4C123BE6PM, TM4C123GE6PM, TM4C123FE6PM, TM4C123FH6PM, TM4C123BH6PM, TM4C123AE6PM, TM4C123AH6PM

Using "Upgrade to Tiva C Series" in stellaris family page in TI, for LM3S818, the part of TM4C1230D5 proposed as a compatible one in Tiva C-series portfolio, but when comparing these MCUs, we could find that there is no any PWM modules for TM4C1230D5, so considering the supported documents in migration from stellaris MCUs to Tiva c-series, we can not upgrade the developed software for LM3S818 to this one using these guides and tools, so there is critical ambiguity in this context: why the online module of ""Upgrade to Tiva C Series" popose this part as a compatible for LM3S818? what is criterion? 

Is not it better and apt for TI that itself upgrade the previous offered motor control softwares especially for LM3S818 to a suitable MCU in Tiva C-series portfolio?

or proposed a minimum footprint compatible from Tiva C-series for LM3S818?

   

  • 0
    Guru 27285 points

    aliasgar panahi said:
    Is not it better and apt for TI that itself upgrade the previous offered motor control softwares especially for LM3S818 to a suitable MCU in Tiva C-series portfolio?

      Hi, this is still HOT problem and if you browse this forum recently I also asked if motor kit is planned to be ported to TIVA series.

     On C2000 motor ware some kit like ACIM are still missing but can be easily adapted from not same as stellaris equivalent was.

     Also Evalbot was an amazing kit and can be best fitted to 3200 series with wifi and all LM3S92 less than ethernet (wifi is better on that way)

     To try substitute your LM3S818 no direct equivalent is available nor pin to pin compatible so as we made you have to rework your project and port software to new series.

     Try the Launchpad mounted series TM4C123GH6PM, is same size of lm3S and has all you need, otherwise a same series is available on 100 and 144 pin version too, for same price/similar size the 100pin can be preferred due to greater flexibility on pin mux, if you plan use both can and uart check for large case.

     Other consideration can be done on your application too.

     Stellaris was less expensive than TIVA and actually from distributor TIVA chip cost more than full Launchpad.

  • 0 in reply to Roberto Romano
    Prodigy 100 points
    Dear Romano
    Thanks for your kind answer, what is your opinion about using piccolo F28027F (instaspin enabled) as a replacement considering only the cost of ICs, from vie point of development time, I think this selection is the best.
  • 0 in reply to aliasgar panahi
    Guru 27285 points

    aliasgar panahi said:
    Thanks for your kind answer, what is your opinion about using piccolo F28027F (instaspin enabled) as a replacement considering only the cost of ICs, from vie point of development time, I think this selection is the best.

     Hi Aliasgar, this way I am not prepared to do a better answer nor I can point to due you don't provided information about what is your application and what kind of motor are you using.

     I recently got a Launchpad 27027F and Boospterpack DRV8301 to evaluate this platform, on first attempt this kit was not so simple to use but I wrote a note on C2000 instaspin forum to help use it, I am far from be productive and I judge myself still at beginner level. First try was on a small syncronous motor and I understood a more manual's reading has to do. I just identified them, tomorrow I plan got an ACIM is more simple to spin when parameter are not known and result on less nervous behaving.

     I am not sure if piccolo series is best but is less expensive than a TIVA, counterpart has no CAN on chip nor QEI hardware due is dedicated to sensorless FOC.

     My primary experience on that processor was on DC DC inverters and PFC not motor spin I begun just few day ago. I am prevalently using MSP430 to drive Step motor or DC brushed and all software I own is there also with Software QEI module. I was planning do a 3 PHase inverter too on MSP but all software ready promise stopped me that way, now is the time to do it and I am evaluating both TIVA and C2000 series to spin 3PH motors.

    As you feel better we can continue here, so please add your ask to porting motor ACIM or move to instaspin forum where people more prepared than me can help both.

  • 0 in reply to Roberto Romano
    Guru 117850 points

    Roberto Romano said:
    Launchpad mounted series TM4C123GH6PM, is same size of lm3S and has all you need

    Hi Roberto,

    You and Luis are "blowing up" the forum w/volume and "depth" of posts.  (not just PF0/PD7, or "search harder" as signature blocker urges)

    However - poster used an LM3S818 - and as you'll recall - that was a 48 pin QFP device.  (we know as we used > 1K LM3S811!)  So - as rebrand "starts" @ 64 pin QFP - cannot be same size.

    And - of course - the pinouts never were compatible - poster's forced to a board spin.

    Those (past) sadly departed 48 pin (or smaller) ARM MCUs are available from (multiple) others - and some of our motor applications (embed the controller w/in the motor) cannot accommodate the size of 64 pin QFP!   

    Long live the "free selection" of package size, memory variants, MCU speeds, peripherals, P&D (price/delivery) - resulting from a "broader search" for suitable ARM MCUs...

  • 0
    TI__Guru**** 244380 points
    Hello Aliasgar,

    The criteria for most part of it looks for the memory footprint match as there is no other method. We have in the past proposed to have peripheral identification also integrated into the search system. In the meantime you can view the product web page

    http://www.ti.com/lsds/ti/microcontrollers_16-bit_32-bit/c2000_performance/control_automation/tm4c12x/products.page

    There are in fact 8 parts which have 8 or more Motion Control PWM outputs. These are the TM4C123GH6PM, TM4C123GE6PM, TM4C123FH6PM, TM4C123FE6PM, TM4C123BH6PM, TM4C123BE6PM, TM4C123AH6PM, TM4C123AE6PM devices.

    C2000 class of devices is a good solution for motor control, however InstaSpin ROM is not a public code, so there would be lot of startup issues (in terms of port over). However you are most welcome to evaluate C2000 and its forum (I have redirected at least 1 post in the past where the user wanted to compare Tiva and C2000 for motor control for the application)... If your application (as Roberto mentioned) requirement is clear it would be useful for us to see if Piccolo does server the end needs at the right price point (I bet it would).

    Regards,
    Amit
  • 0 in reply to Amit Ashara
    Guru 117850 points

    Amit Ashara said:
    Piccolo does server the end needs at the right price point (I bet it would).

    Or not!  When we purchased 1K LM3S811 price from disty Avnet was at/around 4 (USD).  

    That "price point" somehow seems "unmatchable" by Piccolo - I'll thus "take" your bet...   (we do realize you do not make the rules - yet facts are facts!)

  • 0 in reply to Roberto Romano
    Guru 20670 points
    I also have a c2000 launchpad. I actually got it for free on a promotion.
    I decided to ask arround about it to a more experienced user.

    The c2000 top tier actually seems to be much more capable than the tiva with motor control with feedback. More speed, some aided with CLA for some real paralel calculations (very basic) and some even with dual core.
    The chip in the launchpad is actually pretty small but i imagen it gets bigger with the dual core series.

    Now of course it doesnt beat the amount of peripherals a ARM has nor i see it using something like a LCD. But there is a series dual core that has a ARM+C2000.
    The idea seems to use the c2000 for critical calculations and decisions - the brain - and the ARM is to do RAM consuming tasks like control a LCD or less critical, but time consuming, tasks and communications.

    Anyway i didnt really like it because it doesnt have something like Tivaware, didnt really check Instaspin. And also i like the ARM having high ram and amount of peripherals making it more of a swiss army knife in my opinion.
  • 0 in reply to Luis Afonso
    Guru 27285 points

    Luis, C2000 is more DSP than processor and it was a bridge between them, nowaday also DSP has general controller capability and gap was lesser.
    About your launchpad, is instaspin FOC 28027F or simple 28027 I usually used on converter? The first has internal rom but no CLA nor accelelrator, to find them you need expensive High performance 6x series it also carry dual core DSP not bicore dual processor like also are OMAP. Edit: OMAP also has dual core dual processor on both side arm and DSP to perform complex task. Preferred on high end smart phone are now substituted by multicore ARM.
    About C2000 a lot of code and examples exists, they cover a complex domain where a beginner is forever scared by math but believe me also there I encountered some worst beginner screaming about has seen something on youtube...
    Primary difference of C2000 is his specialized high resolution EPWM, fast ADC. Actual TIVA family can overlap some area but again in first application has to be addressed, general discussion as I stated need be specific to application too.

  • 0 in reply to Luis Afonso
    TI__Guru**** 244380 points
    Hello Luis,

    ARM Cortex M7 v/s DSP cores, 1GHz-octal cores on a cell phone: At the end of it comes down to what is the application and what suites it with a reasonable head room at a reasonable cost before a change is required.

    As you well noted you like TivaWare which makes it well suited for you. What if entire TivaWare works on C2000 platform: will you consider it?

    In this case poster has a requirement for replacement of LM3S818 to Tiva-C for which clearly the online tool suggested a part w/o PWM. We need to address that and poster has to address the application question asked quite a few times now.

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

    Hi Amit,

    Amit Ashara said:
    As you well noted you like TivaWare which makes it well suited for you. What if entire TivaWare works on C2000 platform: will you consider it?



    Probably not. First, TivaWare alredy has things to solve on it's own. Second, i don't see a use that i need to use a C2000 vs ARM-M. Not enough experience i guess.

     

    Amit Ashara said:
    In this case poster has a requirement for replacement of LM3S818 to Tiva-C for which clearly the online tool suggested a part w/o PWM. We need to address that and poster has to address the application question asked quite a few times now.


    Well, there aren't any TM4C with 48 LQFP so there's no luck with that from the start. If you want to easily upgrade this makes it impossible.
    There's also a problem. When i go to the older stellaris part referred i see that there's no parameter table! This would make it much easier to compare parameters betwen the TM4C! Now i have to go read the datasheet to see differences, where did that table go? I'm talking about this page 

    Ok let's just see the datasheet tables. The smallest MCU i found that has at least the same features as the stellaris part referred was this one:

    Now, about the tool i am too now curious about the criteria! 

  • 0 in reply to cb1_mobile
    Guru 27285 points

    cb1_mobile said:

    Or not!  When we purchased 1K LM3S811 price from disty Avnet was at/around 4 (USD).

     <Hi CB1, I cannot be so sure nowaday price for that volume on Piccolo can be less or equal too. Fact are 811 small is no more available nor a close substitute, so I am sorry about forgetting case difference, a lot of time elapsed and I never used that entry level part. Original project was on Stallaris 6 89xx and lm3s9b92, all samples are still on their bag due sampling phase was stopped by NRND at end of design phase.

     All software got migrated to TIVA and I am forgotting Stellaris where nothing got to production than few prototipes LX120 launchpad based.