# weirdocollector

Members

10

## Posts posted by weirdocollector

1. ### Help with Hamster Book tutorial (newbie stupid question inside)

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. ### Help with Hamster Book tutorial (newbie stupid question inside)

Thanks !

You're right, it's a math question and not a proper FPGA problem.

I'm now using this formula:

127*SIN(n*2*pi/256) + 128

Almost surely I'm wrong, but I have the sentation the formula in Hamster book cannot give the expected 28 to 228 values.

Thanks again.

3. ### Help with Hamster Book tutorial (newbie stupid question inside)

I've tried with Excel, but I cannot obtain values between 28 and 228.

I've simply applied the formula to values from 0 to 1024, what am I doing wrong?

Thanks again.

4. ### Help with Hamster Book tutorial (newbie stupid question inside)

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 !

5. ### My DUO arrived today

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.

6. ### My DUO arrived today

Just arrived...

Now waiting for an announcement about the acryilic case

This week end won't be wasted

7. ### My DUO arrived today

Got my cute little black butterfly today... Rome, Italy

Mine still have to show up

Hope it hasn't gone lost (...worrying.... )

8. ### My DUO arrived today

Still no joy here in Italy

Hope to get it soon...

9. ### LogicStart Shield for the Papilio DUO

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

10. ### Papilio DUO - Classic Computing Shield

Love the idea of the snap board !

Having 16 GPIO at your disposal is a great feature (you can virtually add everything you want).

Way to go, Jack.