si4438 cca 侦听
/* set GPIO0 for RSSI interrupt / CCA */ txbuf[0] = CMD_GPIO_PIN_CFG; txbuf[1] = 27; /* GPIO[0] = 27: CCA or 37: CCA_LATCH */ txbuf[2] = 0; /* GPIO[1] = DONOTHING */ txbuf[3] = 0; /* GPIO[2] = DONOTHING */ txbuf[4] = 0; /* GPIO[3] = DONOTHING */ txbuf[5] = 0; /* NIRQ = behavior not modified */ txbuf[6] = 0; /* SDO = behavior not modified*/ txbuf[7] = 0; /* GEN_CONFIG = GPIO outputs will have the highest drive strength*/ si446x_SendCommand(8, txbuf); si446x_WaitForCTS(); /* set RSSI threshold */ txbuf[0] = CMD_SET_PROPERTY; txbuf[1] = PROP_MODEM_GROUP; txbuf[2] = 0x03; /* num of property */