weirdocollector

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Posts posted by weirdocollector


  1. Hi Alvie !

    First of all thank you for you taking the time for such a thorough answer: really appreciated :)

    I've used Excel in order to calculate the sine sample values, and your last formula:

    int(128+100*sin($n*2*pi/2048))

    works as expected , giving values between 28 and 228, with 'n' from '0' to '2047'.

    The problem in Hamster Book's formula seems to be the '+1' after the sine (sine(n*PI()/1024)+1)*100), that you have ignored in your formula, that makes the multiplier of '100' to be between '0' and '2', instead between '-1' and '1', giving as a result a different range of values.

    Now to my Papilio ! :)

    Thanks again.


  2. Hi everybody!

    I'm going through the wonderful Hamstrer book with the help of my Papilio Pro :)

    I'm having trouble with the Chapter 16 tutorial about the Delta-Sigma DAC, in creating the required sine wave samples to place in the COE file of the FPGA ROM.

    The suggested formula is "f(n) = int((sine(n*PI()/1024)+1)*100)+128" that, as the texts says, "will give you values between 28 and 228 that you can use".

    How could I generate such values ?

    Any help is really appreciated.

    Thanks a lot !

     


  3. Hello,

     

    I talked with Mike the other day and he has been super, super busy getting a new product out the door at his new job. He said that he expects for there to be a lull in the next couple weeks and that the eBook will be his priority when that happens. 

     

    Hopefully it will all work out and we will see something soon. :)

     

    Jack.

     

    Hi Jack,

     

    just to know if there are any news on the updated book  :)

     

    Thanks a lot.


  4. Hi all,

     

    is it to late, or to costly, to add a DB-9 male connector, to be placed on parallel to the four directional buttons already provided, in order to connect an Atari standard joystick ?

     

    I think it will be much more easy and useful having a true joystick to use, given also the fact that the old on-board mini joystick present on the current LogicStart Megawing has been tossed.

     

    Any way, I've already added to my Papilio DUO pledge (that already included a Classic Computing shield, a case, and a set of wings), a new LogicStart shield  ;)