LeafLabs Garden

A place to share, learn, and grow...

1. 

   samtal
   Member

   Hello experts,

   I acquired the Maple (5) as a result of the Arduino not enabling me the speed and resolution I needed.
   Another major reason was the fact that the STM32F103 is capable of dual simultaneous sampling that, in my application, is critical.
   The speed performance and resolution of the Maple is sufficient (although I wish I could have the Arduino Reference command), but I was surprised to find out that the Maple with the compiler I have (IDE 0.0.9) did not implement the STM dual regular simultaneous ADC mode.
   Is there a way to implement that dual mode with Maple 5? Is there a newer IDE that can do it?

   Thanks,
   Sam

   Posted 4 years ago #
2. 

   gbulmer
   Moderator

   samtal - just to clarify terminology:
   The IDE provides a way to edit, compile, link and upload C/C++ and 'Arduino-style' code.
   The library provides pieces of code which are compiled and run on the Maple's STM32F103.
   AFAIK, the library does not provide code to configure and use the STM32F103 in the way you would like to use it.

   There is nothing to prevent you from using the IDE to write, compile, link and upload any code you would like to run on a Maple.
   It doesn't impose any restrictions beyond those imposed by the underlying gcc-based tool-chain, and that tool-chain supports the STM32F103 being configured and used in every way.

   Is there a way to implement that dual mode with Maple 5?

   Yes, the IDE and tool-chain doesn't stop you doing anything. You do not need a newer IDE. If you are able to read and understand the STM32F103 manual RM0008, and using the libmaple code as a guide, you could write C/C++ code to configure the STM32F103 to implement any and every behaviour that it is capable of using the current Maple IDE.

   If you have problems, and you understand how to ask good questions, please ask here.

   (full disclosure: I am not a member of the LeafLabs staff)

   Posted 4 years ago #
3. 

   dreamcat4
   Member

   Usually its typical to find from the data sheet and / or other relevant Microcontroller manual(s) the memory address to access those registers. There should be some special - purpose registers in the StM32103 to implement such device-specific features. "Using Maple IDE as a guide" means browsing through the C Header files for preprocessor macros (#defines) which offer a convenient label for these address ranges. Most Micro controller code is written this way - its no different for the Arduino either.

   Posted 4 years ago #
4. 

   gbulmer
   Moderator

   Usually its typical to find from the data sheet and / or other relevant Microcontroller manual(s) the memory address to access those registers.

   As I wrote, the relevant manual is RM0008.
   http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/REFERENCE_MANUAL/CD00171190.pdf

   The STM32F ADC is described in section "11 Analog-to-digital converter (ADC) " pages 205 to 242.

   The document "AN3116 Application note: STM32™’s ADC modes and their applications"
   http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/APPLICATION_NOTE/CD00258017.pdf
   might be a helpful overview, but the fact that samtal has got this specific suggests it won't help much.

   The matching firmware:
   http://www.st.com/internet/com/SOFTWARE_RESOURCES/SW_COMPONENT/FIRMWARE/an3116.zip
   may contain enough to get going.
   It looks rather long and complex when starting from a Maple perspective. I think quite a lot of the Maple setup overlaps that and likely works, so much of that ST code is redundant. Also, the ST code is written to a general template so it has quite a lot of stuff which could be skipped while trying to understand what is going on.

   (full disclosure: I am not a member of the LeafLabs staff)

   Posted 4 years ago #
5. 

   samtal
   Member

   Hello all kind helpers.

   I do appreciate all for trying to help, and will look deeper into your replies. I have naturally read through most ST documentation, and that is where I got the idea of using Maple, based on ST ability for dual simultaneous DAC, which unfortunately the Maple does not support.
   My basic understanding was that the Arduino and the Maple are intended to make life easier and simple for non-expert programmers, and be used as an interface layer between low-level users (in programming terms, like myself) and the more complex programming (assembler or C/C++/C#).
   Programming the STM32 in C/C++ contradicts that simplicity idea.
   If using normal programming languages, one should better use one of the many ST (or Microchip, or Atmel or whatever) development boards where all commands are implemented, and the user interface is significantly more user friendly and error corrective. (Some also use Windows graphic API).
   I can accept the answer that not all Maple STM32 commands are implemented at this time, and will be added on later. Otherwise the Arduino / Maple have no advantage.

   And, to be more practical, does anyone have a dual-sampling ADC snippet for the Maple?
   Thanks
   samtal

   Posted 4 years ago #
6. 

   samtal
   Member

   Minor (but important) correction to my previous post:

   The line "Programming the STM32 in C/C++ contradicts that simplicity idea"
   should read:
   "Programming the MAPLE in C/C++ contradicts that simplicity idea".
   Thanks
   samtal

   Posted 4 years ago #
7. 

   samtal
   Member

   Hello,
   I seem to be talking to myself....and I am desperate.
   I acquired the Maple (two pieces to test), but as I am unable to use the STM32 dual ADC, the Maple is not my solution unless...
   Unless someone can come to my rescue.
   I have tried to use ST sample C code, but there seem to be many differences in the IDE interpretation, and as I am not an expert (forgot the days I programmed c...) I find it too complex.
   Does anyone have a code piece that can make the Maple use simultaneous ADC?
   Thanks,
   samtal

   Posted 4 years ago #
8. 

   anton
   Member

   Try new refactor version of libmaple, it has support for ADC2.
   https://github.com/leaflabs/libmaple/blob/refactor/libmaple/adc.c
   You only need to rewrite adc_read function.

   Posted 4 years ago #
9. 

   samtal
   Member

   Thanks Anton.
   I looked into it and tried to include in my app and run, but I get various errors (like: "multiple definition of adc_disable'" and "multiple definition ofadc_init'")

   If possible, I need some more assistance.
   1. Does this file replace the origirnal adc.c file in libmaple 0.0.9 which is different?.
   2. Can you please be more specific and write some basic instructions on how to make it work?

   Thanks,

   samtal

   Posted 4 years ago #
10. 

    anton
    Member

    samtal, download the whole refactor branch https://github.com/leaflabs/libmaple/tree/refactor
    and compile from the command line (type make in libmaple folder)

    Posted 4 years ago #
11. 

    mbolivar
    LeafLabs

    anton, samtal,

    Rather than write a new adc_read(), how about adding dual ADC support with a new function (adc_read_dual(), maybe?) . That way, we can fold your changes into a later libmaple release.

    Posted 4 years ago #
12. 

    samtal
    Member

    mboliver,

    No doubt the best would be if someone knowledgeable (unlike myslef in this case) will expand the Maple commands to dual ADC. example: Add a parameter to the analogRead analogRead(AnalogPin,ADC1 or ADC2).
    Seems as if the only reason it was not done so far is probably because the Arduino does not have that option, but when using the STM32 ARM, that option is expected.
    Who can take up the glove??

    samtal

    Posted 4 years ago #
13. 

    poslathian
    LeafLabs

    While I dont come bearing the elusive reference design - sadly - this thread inspired me to start this new page on the wiki http://wiki.leaflabs.com/index.php?title=ExRequest an "example request" forum, to serve as the seeds of a new cookbook project weve been talking about. Go ahead and post requests for reference designs you just wish you had. If you have neat code recipes, share them! Or take on the challenge of fulfilling someone else's cookbook wish. The first entry is up for grabs - claim eternal glory by writing up a wiki post on dual mode adc sampling!

    Posted 4 years ago #
14. 

    gbulmer
    Moderator

    I've been wondering what the API should look like.

    C/C++ only returns a single value as the return of a function, so the only way to get two sample values from a function are either
    a. use a struct:
    struct DUAL_ADC { int, analogValueA, analogValueB; } analogRead(int analogPinA, int analoguePinB);
    which isn't very typical for most C users.

    b. return multiple values in the parameter list
    analogRead(int analogPinA, int* analogValueAptr, int analogPinB, int* analogValueBptr)

    There are a few C++ idioms, but sticking to the maplelib approach, those C++ idioms would be wrappers for a simple base C API.

    The C++ idiom's I first think of would have an object which represents an ADC. That would lead to the need for an object that represents the 'paired' ADC. IIRC the high-density STM32F parts, which have three ADC's, don't support triple simultaneous sampling, so it would only need that extra dual-ADC object.

    With that idiom, the returned values could be retrieved from the object using 'getters', so it would be enough to have a call which takes the two analogPins to be sampled.

    Any other suggestions or comments?

    Posted 4 years ago #
15. 

    crenn
    Moderator

    There are 2 ways I can think of doing it. Getting the function to pass back a pointer to a 2 member array, or passing pointers of where you want the data stored.

    Posted 4 years ago #

RSS feed for this topic

Reply »

You must log in to post.