pi day - calculation of 3.1415926....

[dannyf]

I learned on the radio that today's the (international?) pi day.

What about a completely useless contest on calculating pi on the most primitive computer of them all: a mcu?

A few angles:

1) on the most primitive mcu: 16 bit? 8 bit? 4 bit? or a 1 bitter?
2) fastest to the given length: pi to 10th digits? 50th digits? or 100 / 1000 digits?

Just need to do it on a mcu. Otherwise, it is not completely useless, 

[kripton2035]

my father did it on an alphatronic calculator in the seventies.
unkown processor = at best a 8bits mcu
entirely in assembly langage, it took a week to get ... 100 digits !

[mboich]

Steve Wozniak (Woz) did 150,000 digits on an Apple II many years ago.  That was a 1MHz, 8 bit micro, with probably 8K of memory.  (Needless to say, it didn't store the result, but spewed it out!)  He did an article for Byte Magazine at the time.

[senso]

My first PI calculation, I copied the algorithm that was shown in the SuperPi help file into my Casio CFX and after 5 seconds it spewed out 6 or 7 digits   

[mariush]

int main()
{
long a=10000,b,c=2800,d,e,f[2801],g;
for(;b-c;) f[++b]=a/5;
for(;d=0,g=c*2;c-=14,printf("%.4d",e+d/a),e=d%a)
for(b=c;d+=f*a,f=d%--g, d/=g--,--b;d*=b);
}

Should be fairly easy to port to even a 4bit microcontroller as long as it has enough memory/flash

[apelly]

int main()
{
long a=10000,b,c=2800,d,e,f[2801],g;
for(;b-c;) f[++b]=a/5;
for(;d=0,g=c*2;c-=14,printf("%.4d",e+d/a),e=d%a)
for(b=c;d+=f*a,f=d%--g, d/=g--,--b;d*=b);
}

Should be fairly easy to port to even a 4bit microcontroller as long as it has enough memory/flash

not if you don't put it an a code block 

Code: [Select]

int main()
{
long a=10000,b,c=2800,d,e,f[2801],g;
for(;b-c;) f[++b]=a/5;
for(;d=0,g=c*2;c-=14,printf("%.4d",e+d/a),e=d%a)
for(b=c;d+=f[b]*a,f[b]=d%--g, d/=g--,--b;d*=b);
}

[Rigby]

Why no sqrt(2) day or phi day?  golden ratio day?

pi isn't very special.

yes, I watched this, and I'm on her side.  Highly recommended viewing.

[kripton2035]

int main()
{
long a=10000,b,c=2800,d,e,f[2801],g;
for(;b-c;) f[++b]=a/5;
for(;d=0,g=c*2;c-=14,printf("%.4d",e+d/a),e=d%a)
for(b=c;d+=f*a,f=d%--g, d/=g--,--b;d*=b);
}

Should be fairly easy to port to even a 4bit microcontroller as long as it has enough memory/flash

the challenge is to calculate an infinite quantity of digits, as long as the mcu can run and has enought memory to store the digits and the calculations.

[Mechatrommer]

swmbo made something like this in under than an hour, she made us happy at least we can continue with whatever our work was during the day, and the most important part is, we are happy...

[PeterG]

swmbo made something like this in under than an hour, she made us happy at least we can continue with whatever our work was during the day, and the most important part is, we are happy...

Yes, fine work indeed. However, are the results repeatable? 

Regards

[Mechatrommer]

Yes, fine work indeed. However, are the results repeatable? 

"good enough", with specified tolerance

[scientist]

swmbo made something like this in under than an hour, she made us happy at least we can continue with whatever our work was during the day, and the most important part is, we are happy...

I demand a CNC'd version!

[miguelvp]

I demand a CNC'd version!

Not CNC'd:



Well maybe can be CNC'd

[GK]

Why no sqrt(2) day or phi day?  golden ratio day?

Or just 1/3 day.......

[miguelvp]

Why no sqrt(2) day or phi day?  golden ratio day?

Or just 1/3 day.......

yup, since Jan 41 and Jan 62 are hard to come by unless they refer to years.

Edit: funny fact, I always have treated Jan 2nd as a 1/2 day