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Hi
I've tried to use my Polaroid Sonar not only for distances up to 2.7 meters. So
I want to check the overflow flag. But my code doesn't work. Can anybody give
me some advises?
Here is my code:
long sonar_sample() {
int start_time;
int help;
overflow_counter=0L;
poke(0x1023, 1); /* clear tic3 flag */
start_time=peekword(0x100e); /* capture start time */
bit_set(0x1008, 0x20); /* trigger pulse */
bit_clear(0x1024,0b10000000); /* TOI cleared => TOF
read by software */
while (!(peek(0x1000) & 0x1)) { /* wait until receive echo */
if (peek(0x1025)&0b10000000)
{
overflow_counter=overflow_counter+1L;
bit_clear(0x1025,0b10000000);
}
if (overflow_counter>=4L)
{
/* if too much time has elapsed, abort */
bit_clear(0x1008, 0x20);
return -1L;
}
defer(); /* let others run while waiting */
}
bit_clear(0x1008, 0x20); /* clear pulse trigger */
help =peekword(0x1014)-start_time;
return overflow_counter*65535L +(long)help; /* tic3 has time of echo */
}
Thanks
Martin
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