Re: Wireless - switchless kernal mod

On 4/3/2018 8:42 AM, Nejat Dilek wrote:
>
> I couldn't find information about that behaviour you described,
> possibly attiny85 doesn't have it.
It does not look like it.  Bummer.  You might see if the other 8 pin 
AVRs have it, as it is relaly useful, if you should decide to make more 
of these.
> I'll possibly stop / start an
> internal timer to measure time.
I would recommend not starting/stopping.  Just set up a free running 
counter, with the accuracy you need, and then do:

static volatile uint8_t ctr;
static volatile uin8t_t bit;

#define NONE 2
#define ONE 1
#define ZERO 0

ISR() { // !CE interrupt
     if(ctr < 10) {  // less than 100uS
         ctr = 0; // error
     } else if (ctr < 20)  // 100-200
         bit = ZERO;
     } else if (ctr < 30) // 200-300
         bit = ONE;
     } else
         ctr = 0; // error
}

ISR() {  //counter 0 compare match, runs at 10uS
     if(ctr < 255)
         ctr++;
}

int main() {
     uint8_t a;
     bit = NONE;
// set counter to run at CLK/8, and count to 10.  This gives 10uS accuracy.
...

     while(1) {
         while(bit == NONE) ;
             a = bit;
             bit = NONE;
             switch(a) {
                 // handle bit data, setting b
             }
     }
}

I'd use a enum or a bit field for the bit variable, but I always forget 
the syntax.

Jim