uint8_t NRF24L01_Init(uint8_t channel, uint8_t payload_size) {
/* Max payload is 32bytes */
if (payload_size > 32) {
payload_size = 32;
}
/* Fill structure */
NRF24L01_Struct.Channel = !channel; /* Set channel to some different value for NRF24L01_SetChannel() function */
NRF24L01_Struct.PayloadSize = payload_size;
NRF24L01_Struct.OutPwr = NRF24L01_OutputPower_0dBm;
NRF24L01_Struct.DataRate = NRF24L01_DataRate_2M;
/* Reset nRF24L01+ to power on registers values */
NRF24L01_SoftwareReset();
/* Channel select */
NRF24L01_SetChannel(channel);
/* Set pipeline to max possible 32 bytes */
NRF24L01_WriteRegister(NRF24L01_REG_RX_PW_P0, NRF24L01_Struct.PayloadSize); // Auto-ACK pipe
NRF24L01_WriteRegister(NRF24L01_REG_RX_PW_P1, NRF24L01_Struct.PayloadSize); // Data payload pipe
NRF24L01_WriteRegister(NRF24L01_REG_RX_PW_P2, NRF24L01_Struct.PayloadSize);
NRF24L01_WriteRegister(NRF24L01_REG_RX_PW_P3, NRF24L01_Struct.PayloadSize);
NRF24L01_WriteRegister(NRF24L01_REG_RX_PW_P4, NRF24L01_Struct.PayloadSize);
NRF24L01_WriteRegister(NRF24L01_REG_RX_PW_P5, NRF24L01_Struct.PayloadSize);
/* Set RF settings (2mbps, output power) */
NRF24L01_SetRF(NRF24L01_Struct.DataRate, NRF24L01_Struct.OutPwr);
/* Config register */
NRF24L01_WriteRegister(NRF24L01_REG_CONFIG, NRF24L01_CONFIG);
/* Enable auto-acknowledgment for all pipes */
NRF24L01_WriteRegister(NRF24L01_REG_EN_AA, 0x3F);
/* Enable RX addresses */
NRF24L01_WriteRegister(NRF24L01_REG_EN_RXADDR, 0x3F);
/* Auto retransmit delay: 1000 (4x250) us and Up to 15 retransmit trials */
NRF24L01_WriteRegister(NRF24L01_REG_SETUP_RETR, 0x4F);
/* Dynamic length configurations: No dynamic length */
NRF24L01_WriteRegister(NRF24L01_REG_DYNPD, (0 << NRF24L01_DPL_P0) | (0 << NRF24L01_DPL_P1) | (0 << NRF24L01_DPL_P2) | (0 << NRF24L01_DPL_P3) | (0 << NRF24L01_DPL_P4) | (0 << NRF24L01_DPL_P5));
/* Clear FIFOs */
NRF24L01_FLUSH_TX();
NRF24L01_FLUSH_RX();
/* Clear interrupts */
NRF24L01_CLEAR_INTERRUPTS;
/* Go to RX mode */
NRF24L01_PowerUpRx();
/* Return OK */
return 1;
}
void NRF24L01_PowerUpRx(void) {
/* Disable RX/TX mode */
NRF24L01_CE_LOW;
/* Clear RX buffer */
NRF24L01_FLUSH_RX(NRF24L01_SPI);
/* Clear interrupts */
NRF24L01_CLEAR_INTERRUPTS;
/* Setup RX mode */
NRF24L01_WriteRegister(NRF24L01_REG_CONFIG, NRF24L01_CONFIG | 1 << NRF24L01_PWR_UP | 1 << NRF24L01_PRIM_RX);
/* Start listening */
NRF24L01_CE_HIGH;
}