Fix calculation of mag^2.

This commit is contained in:
Jared Boone
2015-08-17 11:14:14 -07:00
parent f2c0531bc2
commit adbc5a6f26

View File

@ -56,7 +56,7 @@ void rx_test() {
volatile uint32_t buffer[4096];
uint32_t i = 0;
int16_t magsq;
uint32_t magsq;
int8_t sigi, sigq;
sgpio_cpld_stream_enable();
@ -71,11 +71,7 @@ void rx_test() {
/* find the magnitude squared */
sigi = buffer[i & 4095] & 0xff;
sigq = (buffer[i & 4095] >> 8) & 0xff;
magsq = sigi * sigq;
if ((uint16_t)magsq & 0x8000) {
magsq ^= 0xffff;
magsq++;
}
magsq = sigi * sigi + sigq * sigq;
/* illuminate LED3 only when magsq exceeds threshold */
if (magsq > 0x3c00)