// get random seed from wideband noise rssi
void radio_init () {
hal_disableIRQs();
// manually reset radio
#ifdef CFG_sx1276_radio
hal_pin_rst(0); // drive RST pin low
#else
hal_pin_rst(1); // drive RST pin high
#endif
hal_waitUntil(os_getTime()+ms2osticks(1)); // wait >100us
hal_pin_rst(2); // configure RST pin floating!
hal_waitUntil(os_getTime()+ms2osticks(5)); // wait 5ms
opmode(OPMODE_SLEEP);
// some sanity checks, e.g., read version number
u1_t v = readReg(RegVersion);
#ifdef CFG_sx1276_radio
ASSERT(v == 0x12 );
#elif CFG_sx1272_radio
ASSERT(v == 0x22);
#else
#error Missing CFG_sx1272_radio/CFG_sx1276_radio
#endif
// seed 15-byte randomness via noise rssi
rxlora(RXMODE_RSSI);
while( (readReg(RegOpMode) & OPMODE_MASK) != OPMODE_RX ); // continuous rx
for(int i=1; i<16; i++) {
for(int j=0; j<8; j++) {
u1_t b; // wait for two non-identical subsequent least-significant bits
while( (b = readReg(LORARegRssiWideband) & 0x01) == (readReg(LORARegRssiWideband) & 0x01) );
randbuf[i] = (randbuf[i] << 1) | b;
}
}
randbuf[0] = 16; // set initial index
#ifdef CFG_sx1276mb1_board
// chain calibration
writeReg(RegPaConfig, 0);
// Launch Rx chain calibration for LF band
writeReg(FSKRegImageCal, (readReg(FSKRegImageCal) & RF_IMAGECAL_IMAGECAL_MASK)|RF_IMAGECAL_IMAGECAL_START);
while((readReg(FSKRegImageCal)&RF_IMAGECAL_IMAGECAL_RUNNING) == RF_IMAGECAL_IMAGECAL_RUNNING){ ; }
// Sets a Frequency in HF band
u4_t frf = 868000000;
writeReg(RegFrfMsb, (u1_t)(frf>>16));
writeReg(RegFrfMid, (u1_t)(frf>> 8));
writeReg(RegFrfLsb, (u1_t)(frf>> 0));
// Launch Rx chain calibration for HF band
writeReg(FSKRegImageCal, (readReg(FSKRegImageCal) & RF_IMAGECAL_IMAGECAL_MASK)|RF_IMAGECAL_IMAGECAL_START);
while((readReg(FSKRegImageCal) & RF_IMAGECAL_IMAGECAL_RUNNING) == RF_IMAGECAL_IMAGECAL_RUNNING) { ; }
#endif /* CFG_sx1276mb1_board */
opmode(OPMODE_SLEEP);
hal_enableIRQs();
}
// called by EXTI_IRQHandler
// (set preprocessor option CFG_EXTI_IRQ_HANDLER=sensorirq)
void sensorirq () {
if((EXTI->PR & (1<<INP_PIN)) != 0) { // pending
EXTI->PR = (1<<INP_PIN); // clear irq
// run application callback function in 50ms (debounce)
os_setTimedCallback(&irqjob, os_getTime()+ms2osticks(50), irqjob.func);
}
}
static void blinkfunc (osjob_t* j) {
// toggle LED
ledstate = !ledstate;
debug_led(ledstate);
// reschedule blink job
os_setTimedCallback(j, os_getTime()+ms2osticks(100), blinkfunc);
}