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ardupilot/libraries/AP_HAL_F4Light/RC_NRF_parser.cpp

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/*
(c) 2017 night_ghost@ykoctpa.ru
based on: BetaFlight NRF driver
*/
#include <exti.h>
#include <timer.h>
#include "RCInput.h"
#include <pwm_in.h>
#include <AP_HAL/utility/dsm.h>
#include "sbus.h"
#include "GPIO.h"
#include "ring_buffer_pulse.h"
#include "RC_NRF_parser.h"
using namespace F4Light;
extern const AP_HAL::HAL& hal;
#if defined(BOARD_NRF_CS_PIN) && defined(BOARD_NRF_NAME)
static uint8_t NRF_Buffer[NRF_MAX_PAYLOAD_SIZE];
static uint8_t ackPayload[NRF24L01_MAX_PAYLOAD_SIZE];
NRF_parser::uint8_t rxTxAddr[RX_TX_ADDR_LEN] = {0x4b,0x5c,0x6d,0x7e,0x8f};
static const uint8_t inavRfChannelHoppingCount = INAV_RF_CHANNEL_HOPPING_COUNT_DEFAULT;
static uint8_t inavRfChannelCount;
static uint8_t inavRfChannelIndex;
static uint8_t inavRfChannels[INAV_RF_CHANNEL_COUNT_MAX];
void NRF_parser::init(uint8_t ch){
memset((void *)&val[0], 0, sizeof(val));
_last_signal=0;
_last_change =0;
GPIO::_pinMode(BOARD_NRF24_CS_PIN, OUTPUT);
GPIO::_write(BOARD_NRF24_CS_PIN, 1);
nrf = hal.spi->get_device(BOARD_NRF_NAME);
nrf->register_periodic_callback(FUNCTOR_BIND_MEMBER(&NRF_parser::_timer, bool), 100);
}
void NRF_parser::_timer() {
uint32_t timeNowUs;
switch (protocolState) {
case STATE_BIND:
if (NRF24L01_ReadPayloadIfAvailable(NRF_Buffer, NRF_MAX_PAYLOAD_SIZE)) {
whitenPayload(NRF_Buffer, NRF_MAX_PAYLOAD_SIZE);
const bool bindPacket = checkBindPacket(NRF_Buffer);
if (bindPacket) {
state = RX_SPI_RECEIVED_BIND;
writeBindAckPayload(NRF_Buffer);
// got a bind packet, so set the hopping channels and the rxTxAddr and start listening for data
inavSetBound();
}
}
break;
case STATE_DATA:
timeNowUs = micros();
// read the payload, processing of payload is deferred
if (NRF24L01_ReadPayloadIfAvailable(NRF_Buffer, NRF_MAX_PAYLOAD_SIZE)) {
whitenPayload(NRF_Buffer, NRF_MAX_PAYLOAD_SIZE);
receivedPowerSnapshot = NRF24L01_ReadReg(NRF24L01_09_RPD); // set to 1 if received power > -64dBm
const bool bindPacket = checkBindPacket(NRF_Buffer);
if (bindPacket) {
// transmitter may still continue to transmit bind packets after we have switched to data mode
state = RX_SPI_RECEIVED_BIND;
writeBindAckPayload(NRF_Buffer);
} else {
state = RX_SPI_RECEIVED_DATA;
writeTelemetryAckPayload();
}
}
if ((state == RX_SPI_RECEIVED_DATA) || (timeNowUs > timeOfLastHop + hopTimeout)) {
inavHopToNextChannel();
timeOfLastHop = timeNowUs;
}
break;
}
}
bool NRF_parser::checkBindPacket(const uint8_t *payload)
{
bool bindPacket = false;
if (payload[0] == BIND_PAYLOAD0 && payload[1] == BIND_PAYLOAD1) {
bindPacket = true;
if (protocolState ==STATE_BIND) {
rxTxAddr[0] = payload[2];
rxTxAddr[1] = payload[3];
rxTxAddr[2] = payload[4];
rxTxAddr[3] = payload[5];
rxTxAddr[4] = payload[6];
/*inavRfChannelHoppingCount = payload[7]; // !!TODO not yet implemented on transmitter
if (inavRfChannelHoppingCount > INAV_RF_CHANNEL_COUNT_MAX) {
inavRfChannelHoppingCount = INAV_RF_CHANNEL_COUNT_MAX;
}*/
if (fixedIdPtr != NULL && *fixedIdPtr == 0) {
// copy the rxTxAddr so it can be saved
memcpy(fixedIdPtr, rxTxAddr, sizeof(uint32_t));
}
}
}
return bindPacket;
}
void NRF_parser::whitenPayload(uint8_t *payload, uint8_t len)
{
#ifdef USE_WHITENING
uint8_t whitenCoeff = 0x6b; // 01101011
while (len--) {
for (uint8_t m = 1; m; m <<= 1) {
if (whitenCoeff & 0x80) {
whitenCoeff ^= 0x11;
(*payload) ^= m;
}
whitenCoeff <<= 1;
}
payload++;
}
#else
UNUSED(payload);
UNUSED(len);
#endif
}
void NRF_parser::inavSetBound(void)
{
protocolState = STATE_DATA;
NRF24L01_WriteRegisterMulti(NRF24L01_0A_RX_ADDR_P0, rxTxAddr, RX_TX_ADDR_LEN);
NRF24L01_WriteRegisterMulti(NRF24L01_10_TX_ADDR, rxTxAddr, RX_TX_ADDR_LEN);
timeOfLastHop = micros();
inavRfChannelIndex = 0;
inavSetHoppingChannels();
NRF24L01_SetChannel(inavRfChannels[0]);
#ifdef DEBUG_NRF24_INAV
debug[0] = inavRfChannels[inavRfChannelIndex];
#endif
}
void NRF_parser::writeAckPayload(uint8_t *data, uint8_t length)
{
whitenPayload(data, length);
NRF24L01_WriteReg(NRF24L01_07_STATUS, BV(NRF24L01_07_STATUS_MAX_RT));
NRF24L01_WriteAckPayload(data, length, NRF24L01_PIPE0);
}
void NRF_parser::writeTelemetryAckPayload(void)
{
#ifdef TELEMETRY_NRF24_LTM
// set up telemetry data, send back telemetry data in the ACK packet
static uint8_t sequenceNumber = 0;
static ltm_frame_e ltmFrameType = LTM_FRAME_START;
ackPayload[0] = TELEMETRY_ACK_PAYLOAD0;
ackPayload[1] = sequenceNumber++;
const int ackPayloadSize = getLtmFrame(&ackPayload[2], ltmFrameType) + 2;
++ltmFrameType;
if (ltmFrameType > LTM_FRAME_COUNT) {
ltmFrameType = LTM_FRAME_START;
}
writeAckPayload(ackPayload, ackPayloadSize);
#ifdef DEBUG_NRF24_INAV
debug[1] = ackPayload[1]; // sequenceNumber
debug[2] = ackPayload[2]; // frame type, 'A', 'S' etc
debug[3] = ackPayload[3]; // pitch for AFrame
#endif
#endif
}
void NRF_parser::writeBindAckPayload(uint8_t *payload)
{
#ifdef USE_AUTO_ACKKNOWLEDGEMENT
memcpy(ackPayload, payload, BIND_PAYLOAD_SIZE);
// send back the payload with the first two bytes set to zero as the ack
ackPayload[0] = BIND_ACK_PAYLOAD0;
ackPayload[1] = BIND_ACK_PAYLOAD1;
// respond to request for rfChannelCount;
ackPayload[7] = inavRfChannelHoppingCount;
// respond to request for payloadSize
switch (payloadSize) {
case INAV_PROTOCOL_PAYLOAD_SIZE_MIN:
case INAV_PROTOCOL_PAYLOAD_SIZE_DEFAULT:
case INAV_PROTOCOL_PAYLOAD_SIZE_MAX:
ackPayload[8] = payloadSize;
break;
default:
ackPayload[8] = INAV_PROTOCOL_PAYLOAD_SIZE_DEFAULT;
break;
}
writeAckPayload(ackPayload, BIND_PAYLOAD_SIZE);
#else
UNUSED(payload);
#endif
}
void NRF_parser::inavHopToNextChannel(void)
{
++inavRfChannelIndex;
if (inavRfChannelIndex >= inavRfChannelCount) {
inavRfChannelIndex = 0;
}
NRF24L01_SetChannel(inavRfChannels[inavRfChannelIndex]);
#ifdef DEBUG_NRF24_INAV
debug[0] = inavRfChannels[inavRfChannelIndex];
#endif
}
// The hopping channels are determined by the low bits of rxTxAddr
void NRF_parser::inavSetHoppingChannels(void)
{
#ifdef NO_RF_CHANNEL_HOPPING
// just stay on bind channel, useful for debugging
inavRfChannelCount = 1;
inavRfChannels[0] = INAV_RF_BIND_CHANNEL;
#else
inavRfChannelCount = inavRfChannelHoppingCount;
const uint8_t addr = rxTxAddr[0];
uint8_t ch = 0x10 + (addr & 0x07);
for (int ii = 0; ii < INAV_RF_CHANNEL_COUNT_MAX; ++ii) {
inavRfChannels[ii] = ch;
ch += 0x0c;
}
#endif
}
void NRF_parser::set_val(uint8_t ch, uint16_t val){
if(_val[ch] != val) {
_val[ch] = val;
_last_change = systick_uptime();
}
}
void NRF_parser::inavNrf24SetRcDataFromPayload(uint16_t *rcData, const uint8_t *payload)
{
memset(_val, 0, sizeof(_val));
// payload[0] and payload[1] are zero in DATA state
// the AETR channels have 10 bit resolution
uint8_t lowBits = payload[6]; // least significant bits for AETR
set_val(RC_SPI_ROLL, PWM_RANGE_MIN + ((payload[2] << 2) | (lowBits & 0x03)) ); // Aileron
lowBits >>= 2;
set_val(RC_SPI_PITCH, PWM_RANGE_MIN + ((payload[3] << 2) | (lowBits & 0x03)) ); // Elevator
lowBits >>= 2;
set_val(RC_SPI_THROTTLE, PWM_RANGE_MIN + ((payload[4] << 2) | (lowBits & 0x03)) ); // Throttle
lowBits >>= 2;
set_val(RC_SPI_YAW, PWM_RANGE_MIN + ((payload[5] << 2) | (lowBits & 0x03)) ); // Rudder
if (payloadSize == INAV_PROTOCOL_PAYLOAD_SIZE_MIN) {
// small payload variant of protocol, supports 6 channels
set_val(RC_SPI_AUX1, PWM_RANGE_MIN + (payload[7] << 2) );
set_val(RC_SPI_AUX2, PWM_RANGE_MIN + (payload[1] << 2) );
_channels = RC_SPI_AUX2+1;
} else {
// channel AUX1 is used for rate, as per the deviation convention
const uint8_t rate = payload[7];
// AUX1
if (rate == RATE_HIGH) {
set_val(RC_CHANNEL_RATE, PWM_RANGE_MAX);
} else if (rate == RATE_MID) {
set_val(RC_CHANNEL_RATE, PWM_RANGE_MIDDLE);
} else {
set_val(RC_CHANNEL_RATE, PWM_RANGE_MIN);
}
// channels AUX2 to AUX7 use the deviation convention
const uint8_t flags = payload[8];
set_val(RC_CHANNEL_FLIP, (flags & FLAG_FLIP) ? PWM_RANGE_MAX : PWM_RANGE_MIN ); // AUX2
set_val(RC_CHANNEL_PICTURE, (flags & FLAG_PICTURE) ? PWM_RANGE_MAX : PWM_RANGE_MIN ); // AUX3
set_val(RC_CHANNEL_VIDEO, (flags & FLAG_VIDEO) ? PWM_RANGE_MAX : PWM_RANGE_MIN ); // AUX4
set_val(RC_CHANNEL_HEADLESS, (flags & FLAG_HEADLESS) ? PWM_RANGE_MAX : PWM_RANGE_MIN ); //AUX5
set_val(RC_CHANNEL_RTH, (flags & FLAG_RTH) ? PWM_RANGE_MAX : PWM_RANGE_MIN ); // AUX6
// channels AUX7 to AUX10 have 10 bit resolution
lowBits = payload[13]; // least significant bits for AUX7 to AUX10
set_val(RC_SPI_AUX7, PWM_RANGE_MIN + ((payload[9] << 2) | (lowBits & 0x03)) );
lowBits >>= 2;
set_val(RC_SPI_AUX8, PWM_RANGE_MIN + ((payload[10] << 2) | (lowBits & 0x03)) );
lowBits >>= 2;
set_val(RC_SPI_AUX9, PWM_RANGE_MIN + ((payload[11] << 2) | (lowBits & 0x03)) );
lowBits >>= 2;
set_val(RC_SPI_AUX10, PWM_RANGE_MIN + ((payload[12] << 2) | (lowBits & 0x03)) );
lowBits >>= 2;
// channels AUX11 and AUX12 have 8 bit resolution
set_val(RC_SPI_AUX11, PWM_RANGE_MIN + (payload[14] << 2) );
set_val(RC_SPI_AUX12, PWM_RANGE_MIN + (payload[15] << 2) );
_channels = RC_SPI_AUX12+1;
}
if (payloadSize == INAV_PROTOCOL_PAYLOAD_SIZE_MAX) {
// large payload variant of protocol
// channels AUX13 to AUX16 have 8 bit resolution
set_val(RC_SPI_AUX13, PWM_RANGE_MIN + (payload[16] << 2) );
set_val(RC_SPI_AUX14, PWM_RANGE_MIN + (payload[17] << 2) );
_channels = RC_SPI_AUX14+1;
}
_last_signal = systick_uptime();
}
void NRF_parser::inavNrf24Setup(const uint32_t *fixedId)
{
// sets PWR_UP, EN_CRC, CRCO - 2 byte CRC, only get IRQ pin interrupt on RX_DR
NRF24L01_Initialize(BV(NRF24L01_00_CONFIG_EN_CRC) | BV(NRF24L01_00_CONFIG_CRCO) | BV(NRF24L01_00_CONFIG_MASK_MAX_RT) | BV(NRF24L01_00_CONFIG_MASK_TX_DS));
#ifdef USE_AUTO_ACKKNOWLEDGEMENT
NRF24L01_WriteReg(NRF24L01_01_EN_AA, BV(NRF24L01_01_EN_AA_ENAA_P0)); // auto acknowledgment on P0
NRF24L01_WriteReg(NRF24L01_02_EN_RXADDR, BV(NRF24L01_02_EN_RXADDR_ERX_P0));
NRF24L01_WriteReg(NRF24L01_03_SETUP_AW, NRF24L01_03_SETUP_AW_5BYTES); // 5-byte RX/TX address
NRF24L01_WriteReg(NRF24L01_04_SETUP_RETR, 0);
NRF24L01_Activate(0x73); // activate R_RX_PL_WID, W_ACK_PAYLOAD, and W_TX_PAYLOAD_NOACK registers
NRF24L01_WriteReg(NRF24L01_1D_FEATURE, BV(NRF24L01_1D_FEATURE_EN_ACK_PAY) | BV(NRF24L01_1D_FEATURE_EN_DPL));
NRF24L01_WriteReg(NRF24L01_1C_DYNPD, BV(NRF24L01_1C_DYNPD_DPL_P0)); // enable dynamic payload length on P0
//NRF24L01_Activate(0x73); // deactivate R_RX_PL_WID, W_ACK_PAYLOAD, and W_TX_PAYLOAD_NOACK registers
NRF24L01_WriteRegisterMulti(NRF24L01_10_TX_ADDR, rxTxAddr, RX_TX_ADDR_LEN);
#else
NRF24L01_SetupBasic();
#endif
NRF24L01_WriteReg(NRF24L01_06_RF_SETUP, NRF24L01_06_RF_SETUP_RF_DR_250Kbps | NRF24L01_06_RF_SETUP_RF_PWR_n12dbm);
// RX_ADDR for pipes P1-P5 are left at default values
NRF24L01_WriteRegisterMulti(NRF24L01_0A_RX_ADDR_P0, rxTxAddr, RX_TX_ADDR_LEN);
NRF24L01_WriteReg(NRF24L01_11_RX_PW_P0, payloadSize);
#ifdef USE_BIND_ADDRESS_FOR_DATA_STATE
inavSetBound();
UNUSED(fixedId);
#else
fixedId = NULL; // !!TODO remove this once configurator supports setting rx_id
if (fixedId == NULL || *fixedId == 0) {
fixedIdPtr = NULL;
protocolState = STATE_BIND;
inavRfChannelCount = 1;
inavRfChannelIndex = 0;
NRF24L01_SetChannel(INAV_RF_BIND_CHANNEL);
} else {
fixedIdPtr = (uint32_t*)fixedId;
// use the rxTxAddr provided and go straight into DATA_STATE
memcpy(rxTxAddr, fixedId, sizeof(uint32_t));
rxTxAddr[4] = RX_TX_ADDR_4;
inavSetBound();
}
#endif
NRF24L01_SetRxMode(); // enter receive mode to start listening for packets
// put a null packet in the transmit buffer to be sent as ACK on first receive
writeAckPayload(ackPayload, payloadSize);
}
///////////////////////
#define NRF24_CE_HI() cs_assert()
#define NRF24_CE_LO() cs_release()
// Instruction Mnemonics
// nRF24L01: Table 16. Command set for the nRF24L01 SPI. Product Specification, p46
// nRF24L01+: Table 20. Command set for the nRF24L01+ SPI. Product Specification, p51
#define R_REGISTER 0x00
#define W_REGISTER 0x20
#define REGISTER_MASK 0x1F
#define ACTIVATE 0x50
#define R_RX_PL_WID 0x60
#define R_RX_PAYLOAD 0x61
#define W_TX_PAYLOAD 0xA0
#define W_ACK_PAYLOAD 0xA8
#define FLUSH_TX 0xE1
#define FLUSH_RX 0xE2
#define REUSE_TX_PL 0xE3
#define NOP 0xFF
uint8_t rxSpiTransferByte(uint8_t data){
uint8_t bt;
// const uint8_t *send, uint32_t send_len, uint8_t *recv, uint32_t recv_len
nrf->transfer(&data,1,&bt,1);
return bt;
}
uint8_t rxSpiWriteByte(uint8_t data)
{
ENABLE_RX();
const uint8_t ret = rxSpiTransferByte(data);
DISABLE_RX();
return ret;
}
void rxSpiWriteCommand(uint8_t reg, uint8_t data){
uint8_t bt[2] = {reg, data };
nrf->transfer(&bt,2,NULL,0);
}
void rxSpiWriteCommandMulti(uint8_t reg, const uint8_t *data, uint8_t length){
uint8_t bt[length+1];
bt[0]=reg;
for(uint8_t i=0;i<length;i++) {
bt[i+1] = data[i];
}
nrf->transfer(&bt,length,NULL,0);
}
void rxSpiReadCommand(uint8_t reg, uint8_t bt){
nrf->transfer(reg);
return nrf->transfer(bt);
}
bool rxSpiReadCommandMulti(uint8_t reg, uint8_t op, uint8_t *data, uint8_t length)
const uint8_t ret = rxSpiTransferByte(reg);
for (uint8_t i = 0; i < length; i++) {
data[i] = rxSpiTransferByte(op);
}
return ret;
}
void NRF24L01_WriteReg(uint8_t reg, uint8_t data)
{
rxSpiWriteCommand(W_REGISTER | (REGISTER_MASK & reg), data);
}
void NRF24L01_WriteRegisterMulti(uint8_t reg, const uint8_t *data, uint8_t length)
{
rxSpiWriteCommandMulti(W_REGISTER | ( REGISTER_MASK & reg), data, length);
}
/*
* Transfer the payload to the nRF24L01 TX FIFO
* Packets in the TX FIFO are transmitted when the
* nRF24L01 next enters TX mode
*/
uint8_t NRF24L01_WritePayload(const uint8_t *data, uint8_t length)
{
return rxSpiWriteCommandMulti(W_TX_PAYLOAD, data, length);
}
uint8_t NRF24L01_WriteAckPayload(const uint8_t *data, uint8_t length, uint8_t pipe)
{
return rxSpiWriteCommandMulti(W_ACK_PAYLOAD | (pipe & 0x07), data, length);
}
uint8_t NRF24L01_ReadReg(uint8_t reg)
{
return rxSpiReadCommand(R_REGISTER | (REGISTER_MASK & reg), NOP);
}
uint8_t NRF24L01_ReadRegisterMulti(uint8_t reg, uint8_t *data, uint8_t length)
{
return rxSpiReadCommandMulti(R_REGISTER | (REGISTER_MASK & reg), NOP, data, length);
}
/*
* Read a packet from the nRF24L01 RX FIFO.
*/
uint8_t NRF24L01_ReadPayload(uint8_t *data, uint8_t length)
{
return rxSpiReadCommandMulti(R_RX_PAYLOAD, NOP, data, length);
}
/*
* Empty the transmit FIFO buffer.
*/
void NRF24L01_FlushTx()
{
rxSpiWriteByte(FLUSH_TX);
}
/*
* Empty the receive FIFO buffer.
*/
void NRF24L01_FlushRx()
{
rxSpiWriteByte(FLUSH_RX);
}
uint8_t NRF24L01_Activate(uint8_t code)
{
return rxSpiWriteCommand(ACTIVATE, code);
}
// standby configuration, used to simplify switching between RX, TX, and Standby modes
static uint8_t standbyConfig;
void NRF24L01_Initialize(uint8_t baseConfig)
{
standbyConfig = BV(NRF24L01_00_CONFIG_PWR_UP) | baseConfig;
NRF24_CE_LO();
// nRF24L01+ needs 100 milliseconds settling time from PowerOnReset to PowerDown mode
static const timeUs_t settlingTimeUs = 100000;
const timeUs_t currentTimeUs = micros();
if (currentTimeUs < settlingTimeUs) {
delayMicroseconds(settlingTimeUs - currentTimeUs);
}
// now in PowerDown mode
NRF24L01_WriteReg(NRF24L01_00_CONFIG, standbyConfig); // set PWR_UP to enter Standby mode
// nRF24L01+ needs 4500 microseconds from PowerDown mode to Standby mode, for crystal oscillator startup
delayMicroseconds(4500);
// now in Standby mode
}
/*
* Common setup of registers
*/
void NRF24L01_SetupBasic(void)
{
NRF24L01_WriteReg(NRF24L01_01_EN_AA, 0x00); // No auto acknowledgment
NRF24L01_WriteReg(NRF24L01_02_EN_RXADDR, BV(NRF24L01_02_EN_RXADDR_ERX_P0));
NRF24L01_WriteReg(NRF24L01_03_SETUP_AW, NRF24L01_03_SETUP_AW_5BYTES); // 5-byte RX/TX address
NRF24L01_WriteReg(NRF24L01_1C_DYNPD, 0x00); // Disable dynamic payload length on all pipes
}
/*
* Enter standby mode
*/
void NRF24L01_SetStandbyMode(void)
{
// set CE low and clear the PRIM_RX bit to enter standby mode
NRF24_CE_LO();
NRF24L01_WriteReg(NRF24L01_00_CONFIG, standbyConfig);
}
/*
* Enter receive mode
*/
void NRF24L01_SetRxMode(void)
{
NRF24_CE_LO(); // drop into standby mode
// set the PRIM_RX bit
NRF24L01_WriteReg(NRF24L01_00_CONFIG, standbyConfig | BV(NRF24L01_00_CONFIG_PRIM_RX));
NRF24L01_ClearAllInterrupts();
// finally set CE high to start enter RX mode
NRF24_CE_HI();
// nRF24L01+ will now transition from Standby mode to RX mode after 130 microseconds settling time
}
/*
* Enter transmit mode. Anything in the transmit FIFO will be transmitted.
*/
void NRF24L01_SetTxMode(void)
{
// Ensure in standby mode, since can only enter TX mode from standby mode
NRF24L01_SetStandbyMode();
NRF24L01_ClearAllInterrupts();
// pulse CE for 10 microseconds to enter TX mode
NRF24_CE_HI();
delayMicroseconds(10);
NRF24_CE_LO();
// nRF24L01+ will now transition from Standby mode to TX mode after 130 microseconds settling time.
// Transmission will then begin and continue until TX FIFO is empty.
}
void NRF24L01_ClearAllInterrupts(void)
{
// Writing to the STATUS register clears the specified interrupt bits
NRF24L01_WriteReg(NRF24L01_07_STATUS, BV(NRF24L01_07_STATUS_RX_DR) | BV(NRF24L01_07_STATUS_TX_DS) | BV(NRF24L01_07_STATUS_MAX_RT));
}
bool NRF24L01_ReadPayloadIfAvailable(uint8_t *data, uint8_t length)
{
if (NRF24L01_ReadReg(NRF24L01_17_FIFO_STATUS) & BV(NRF24L01_17_FIFO_STATUS_RX_EMPTY)) {
return false;
}
NRF24L01_ReadPayload(data, length);
return true;
}
#endif // BOARD_NRF24_CS_PIN
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