in de mix
Fork of RF24 by
RF24.cpp
- Committer:
- akashvibhute
- Date:
- 2015-07-06
- Revision:
- 0:bb74812ac6bb
- Child:
- 1:00706a42491e
File content as of revision 0:bb74812ac6bb:
/* Copyright (C) 2011 J. Coliz <maniacbug@ymail.com> This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License version 2 as published by the Free Software Foundation. */ #include "RF24.h" /****************************************************************************/ void RF24::csn(int mode) { // Minimum ideal spi bus speed is 2x data rate // If we assume 2Mbs data rate and 16Mhz clock, a // divider of 4 is the minimum we want. // CLK:BUS 8Mhz:2Mhz, 16Mhz:4Mhz, or 20Mhz:5Mhz //#ifdef ARDUINO // spi.setBitOrder(MSBFIRST); // spi.setDataMode(spi_MODE0); // spi.setClockDivider(spi_CLOCK_DIV4); //#endif // digitalWrite(csn_pin,mode); csn_pin = mode; } /****************************************************************************/ void RF24::ce(int level) { //digitalWrite(ce_pin,level); ce_pin = level; } /****************************************************************************/ uint8_t RF24::read_register(uint8_t reg, uint8_t* buf, uint8_t len) { uint8_t status; csn(LOW); status = spi.write( R_REGISTER | ( REGISTER_MASK & reg ) ); while ( len-- ) *buf++ = spi.write(0xff); csn(HIGH); return status; } /****************************************************************************/ uint8_t RF24::read_register(uint8_t reg) { csn(LOW); spi.write( R_REGISTER | ( REGISTER_MASK & reg ) ); uint8_t result = spi.write(0xff); csn(HIGH); return result; } /****************************************************************************/ uint8_t RF24::write_register(uint8_t reg, const uint8_t* buf, uint8_t len) { uint8_t status; csn(LOW); status = spi.write( W_REGISTER | ( REGISTER_MASK & reg ) ); while ( len-- ) spi.write(*buf++); csn(HIGH); return status; } /****************************************************************************/ uint8_t RF24::write_register(uint8_t reg, uint8_t value) { uint8_t status; // IF_SERIAL_DEBUG(printf(("write_register(%02x,%02x)\r\n"),reg,value)); csn(LOW); status = spi.write( W_REGISTER | ( REGISTER_MASK & reg ) ); spi.write(value); csn(HIGH); return status; } /****************************************************************************/ uint8_t RF24::write_payload(const void* buf, uint8_t len) { uint8_t status; const uint8_t* current = reinterpret_cast<const uint8_t*>(buf); uint8_t data_len = min(len,payload_size); uint8_t blank_len = dynamic_payloads_enabled ? 0 : payload_size - data_len; //printf("[Writing %u bytes %u blanks]",data_len,blank_len); csn(LOW); status = spi.write( W_TX_PAYLOAD ); while ( data_len-- ) spi.write(*current++); while ( blank_len-- ) spi.write(0); csn(HIGH); return status; } /****************************************************************************/ uint8_t RF24::read_payload(void* buf, uint8_t len) { uint8_t status; uint8_t* current = reinterpret_cast<uint8_t*>(buf); uint8_t data_len = min(len,payload_size); uint8_t blank_len = dynamic_payloads_enabled ? 0 : payload_size - data_len; //printf("[Reading %u bytes %u blanks]",data_len,blank_len); csn(LOW); status = spi.write( R_RX_PAYLOAD ); while ( data_len-- ) *current++ = spi.write(0xff); while ( blank_len-- ) spi.write(0xff); csn(HIGH); return status; } /****************************************************************************/ uint8_t RF24::flush_rx(void) { uint8_t status; csn(LOW); status = spi.write( FLUSH_RX ); csn(HIGH); return status; } /****************************************************************************/ uint8_t RF24::flush_tx(void) { uint8_t status; csn(LOW); status = spi.write( FLUSH_TX ); csn(HIGH); return status; } /****************************************************************************/ uint8_t RF24::get_status(void) { uint8_t status; csn(LOW); status = spi.write( NOP ); csn(HIGH); return status; } /****************************************************************************/ void RF24::print_status(uint8_t status) { printf(("STATUS\t\t = 0x%02x RX_DR=%x TX_DS=%x MAX_RT=%x RX_P_NO=%x TX_FULL=%x\r\n"), status, (status & _BV(RX_DR))?1:0, (status & _BV(TX_DS))?1:0, (status & _BV(MAX_RT))?1:0, ((status >> RX_P_NO) & 7), (status & _BV(TX_FULL))?1:0 ); } /****************************************************************************/ void RF24::print_observe_tx(uint8_t value) { printf(("OBSERVE_TX=%02x: POLS_CNT=%x ARC_CNT=%x\r\n"), value, (value >> PLOS_CNT) & 15, (value >> ARC_CNT) & 15 ); } /****************************************************************************/ void RF24::print_byte_register(const char* name, uint8_t reg, uint8_t qty) { // char extra_tab = strlen(name) < 8 ? '\t' : 0; printf("%s =",name); while (qty--) printf((" 0x%02x"),read_register(reg++)); printf(("\r\n")); } /****************************************************************************/ void RF24::print_address_register(const char* name, uint8_t reg, uint8_t qty) { // char extra_tab = strlen_P(name) < 8 ? '\t' : 0; printf("%s =",name); while (qty--) { uint8_t buffer[5]; read_register(reg++,buffer,sizeof buffer); printf((" 0x")); uint8_t* bufptr = buffer + sizeof buffer; while( --bufptr >= buffer ) printf(("%02x"),*bufptr); } printf(("\r\n")); } /****************************************************************************/ RF24::RF24(PinName mosi, PinName miso, PinName sck, PinName _csnpin, PinName _cepin): ce_pin(_cepin), csn_pin(_csnpin), wide_band(true), p_variant(false), payload_size(32), ack_payload_available(false), dynamic_payloads_enabled(false), pipe0_reading_address(0), spi(mosi, miso, sck) { spi.frequency(10000000/5); // 2Mbit, 1/5th the maximum transfer rate for the spi bus spi.format(8,0); // 8-bit, ClockPhase = 0, ClockPolarity = 0 wait_ms(100); } /****************************************************************************/ void RF24::setChannel(uint8_t channel) { // TODO: This method could take advantage of the 'wide_band' calculation // done in setChannel() to require certain channel spacing. const uint8_t max_channel = 127; write_register(RF_CH,min(channel,max_channel)); } /****************************************************************************/ void RF24::setPayloadSize(uint8_t size) { const uint8_t max_payload_size = 32; payload_size = min(size,max_payload_size); } /****************************************************************************/ uint8_t RF24::getPayloadSize(void) { return payload_size; } /****************************************************************************/ static const char rf24_datarate_e_str_0[] = "1MBPS"; static const char rf24_datarate_e_str_1[] = "2MBPS"; static const char rf24_datarate_e_str_2[] = "250KBPS"; static const char * const rf24_datarate_e_str_P[] = { rf24_datarate_e_str_0, rf24_datarate_e_str_1, rf24_datarate_e_str_2, }; static const char rf24_model_e_str_0[] = "nRF24L01"; static const char rf24_model_e_str_1[] = "nRF24L01+"; static const char * const rf24_model_e_str_P[] = { rf24_model_e_str_0, rf24_model_e_str_1, }; static const char rf24_crclength_e_str_0[] = "Disabled"; static const char rf24_crclength_e_str_1[] = "8 bits"; static const char rf24_crclength_e_str_2[] = "16 bits" ; static const char * const rf24_crclength_e_str_P[] = { rf24_crclength_e_str_0, rf24_crclength_e_str_1, rf24_crclength_e_str_2, }; static const char rf24_pa_dbm_e_str_0[] = "PA_MIN"; static const char rf24_pa_dbm_e_str_1[] = "PA_LOW"; static const char rf24_pa_dbm_e_str_2[] = "PA_MED"; static const char rf24_pa_dbm_e_str_3[] = "PA_HIGH"; static const char * const rf24_pa_dbm_e_str_P[] = { rf24_pa_dbm_e_str_0, rf24_pa_dbm_e_str_1, rf24_pa_dbm_e_str_2, rf24_pa_dbm_e_str_3, }; void RF24::printDetails(void) { print_status(get_status()); print_address_register(("RX_ADDR_P0-1"),RX_ADDR_P0,2); print_byte_register(("RX_ADDR_P2-5"),RX_ADDR_P2,4); print_address_register(("TX_ADDR"),TX_ADDR); print_byte_register(("RX_PW_P0-6"),RX_PW_P0,6); print_byte_register(("EN_AA"),EN_AA); print_byte_register(("EN_RXADDR"),EN_RXADDR); print_byte_register(("RF_CH"),RF_CH); print_byte_register(("RF_SETUP"),RF_SETUP); print_byte_register(("CONFIG"),CONFIG); print_byte_register(("DYNPD/FEATURE"),DYNPD,2); printf(("Data Rate\t = %s\r\n"), rf24_datarate_e_str_P[getDataRate()]); printf(("Model\t\t = %s\r\n"), rf24_model_e_str_P[isPVariant()]); printf(("CRC Length\t = %s\r\n"),rf24_crclength_e_str_P[getCRCLength()]); printf(("PA Power\t = %s\r\n"),rf24_pa_dbm_e_str_P[getPALevel()]); } /****************************************************************************/ void RF24::begin(void) { // Initialize pins // pinMode(ce_pin,OUTPUT); // pinMode(csn_pin,OUTPUT); // Initialize spi bus //spi.begin(); mainTimer.start(); ce(LOW); csn(HIGH); // Must allow the radio time to settle else configuration bits will not necessarily stick. // This is actually only required following power up but some settling time also appears to // be required after resets too. For full coverage, we'll always assume the worst. // Enabling 16b CRC is by far the most obvious case if the wrong timing is used - or skipped. // Technically we require 4.5ms + 14us as a worst case. We'll just call it 5ms for good measure. // WARNING: wait_ms is based on P-variant whereby non-P *may* require different timing. wait_ms( 5 ) ; // Set 1500uS (minimum for 32B payload in ESB@250KBPS) timeouts, to make testing a little easier // WARNING: If this is ever lowered, either 250KBS mode with AA is broken or maximum packet // sizes must never be used. See documentation for a more complete explanation. write_register(SETUP_RETR,(4 << ARD) | (15 << ARC)); // Restore our default PA level setPALevel( RF24_PA_MAX ) ; // Determine if this is a p or non-p RF24 module and then // reset our data rate back to default value. This works // because a non-P variant won't allow the data rate to // be set to 250Kbps. if( setDataRate( RF24_250KBPS ) ) { p_variant = true ; } // Then set the data rate to the slowest (and most reliable) speed supported by all // hardware. setDataRate( RF24_1MBPS ) ; // Initialize CRC and request 2-byte (16bit) CRC setCRCLength( RF24_CRC_16 ) ; // Disable dynamic payloads, to match dynamic_payloads_enabled setting write_register(DYNPD,0); // Reset current status // Notice reset and flush is the last thing we do write_register(STATUS,_BV(RX_DR) | _BV(TX_DS) | _BV(MAX_RT) ); // Set up default configuration. Callers can always change it later. // This channel should be universally safe and not bleed over into adjacent // spectrum. //setChannel(76); setChannel(90); // Flush buffers flush_rx(); flush_tx(); // set EN_RXADDRR to 0 to fix pipe 0 from receiving write_register(EN_RXADDR, 0); } /****************************************************************************/ void RF24::startListening(void) { write_register(CONFIG, read_register(CONFIG) | _BV(PWR_UP) | _BV(PRIM_RX)); write_register(STATUS, _BV(RX_DR) | _BV(TX_DS) | _BV(MAX_RT) ); // Restore the pipe0 adddress, if exists if (pipe0_reading_address) write_register(RX_ADDR_P0, reinterpret_cast<const uint8_t*>(&pipe0_reading_address), 5); // Flush buffers flush_rx(); flush_tx(); // Go! ce(HIGH); // wait for the radio to come up (130us actually only needed) // wait_msMicroseconds(130); wait_us(130); } /****************************************************************************/ void RF24::stopListening(void) { ce(LOW); flush_tx(); flush_rx(); } /****************************************************************************/ void RF24::powerDown(void) { write_register(CONFIG,read_register(CONFIG) & ~_BV(PWR_UP)); } /****************************************************************************/ void RF24::powerUp(void) { write_register(CONFIG,read_register(CONFIG) | _BV(PWR_UP)); } /******************************************************************/ bool RF24::write( const void* buf, uint8_t len ) { bool result = false; // Begin the write startWrite(buf,len); // ------------ // At this point we could return from a non-blocking write, and then call // the rest after an interrupt // Instead, we are going to block here until we get TX_DS (transmission completed and ack'd) // or MAX_RT (maximum retries, transmission failed). Also, we'll timeout in case the radio // is flaky and we get neither. // IN the end, the send should be blocking. It comes back in 60ms worst case, or much faster // if I tighted up the retry logic. (Default settings will be 1500us. // Monitor the send uint8_t observe_tx; uint8_t status; uint32_t sent_at = mainTimer.read_ms(); const uint32_t timeout = 500; //ms to wait for timeout do { status = read_register(OBSERVE_TX,&observe_tx,1); // IF_SERIAL_DEBUG(Serial.print(observe_tx,HEX)); } while( ! ( status & ( _BV(TX_DS) | _BV(MAX_RT) ) ) && ( mainTimer.read_ms() - sent_at < timeout ) ); // The part above is what you could recreate with your own interrupt handler, // and then call this when you got an interrupt // ------------ // Call this when you get an interrupt // The status tells us three things // * The send was successful (TX_DS) // * The send failed, too many retries (MAX_RT) // * There is an ack packet waiting (RX_DR) bool tx_ok, tx_fail; whatHappened(tx_ok,tx_fail,ack_payload_available); //printf("%u%u%u\r\n",tx_ok,tx_fail,ack_payload_available); result = tx_ok; // IF_SERIAL_DEBUG(Serial.print(result?"...OK.":"...Failed")); // Handle the ack packet if ( ack_payload_available ) { ack_payload_length = getDynamicPayloadSize(); // IF_SERIAL_DEBUG(Serial.print("[AckPacket]/")); // IF_SERIAL_DEBUG(Serial.println(ack_payload_length,DEC)); } // Yay, we are done. // Power down // powerDown(); // Flush buffers (Is this a relic of past experimentation, and not needed anymore? // flush_tx(); return result; } /****************************************************************************/ void RF24::startWrite( const void* buf, uint8_t len ) { // Transmitter power-up write_register(CONFIG, ( read_register(CONFIG) | _BV(PWR_UP) ) & ~_BV(PRIM_RX) ); // wait_msMicroseconds(150); wait_us(130); // Send the payload write_payload( buf, len ); // Allons! ce(HIGH); // wait_msMicroseconds(15); wait_us(15); ce(LOW); } /****************************************************************************/ uint8_t RF24::getDynamicPayloadSize(void) { uint8_t result = 0; csn(LOW); spi.write( R_RX_PL_WID ); result = spi.write(0xff); csn(HIGH); return result; } /****************************************************************************/ bool RF24::available(void) { return available(NULL); } /****************************************************************************/ bool RF24::available(uint8_t* pipe_num) { uint8_t status = get_status(); // Too noisy, enable if you really want lots o data!! //IF_SERIAL_DEBUG(print_status(status)); bool result = ( status & _BV(RX_DR) ); if (result) { // If the caller wants the pipe number, include that if ( pipe_num ) *pipe_num = ( status >> RX_P_NO ) & 7; // Clear the status bit // ??? Should this REALLY be cleared now? Or wait until we // actually READ the payload? write_register(STATUS,_BV(RX_DR) ); // Handle ack payload receipt if ( status & _BV(TX_DS) ) { write_register(STATUS,_BV(TX_DS)); } } return result; } /****************************************************************************/ bool RF24::read( void* buf, uint8_t len ) { // Fetch the payload read_payload( buf, len ); // was this the last of the data available? return read_register(FIFO_STATUS) & _BV(RX_EMPTY); } /****************************************************************************/ void RF24::whatHappened(bool& tx_ok,bool& tx_fail,bool& rx_ready) { // Read the status & reset the status in one easy call // Or is that such a good idea? uint8_t status = write_register(STATUS,_BV(RX_DR) | _BV(TX_DS) | _BV(MAX_RT) ); // Report to the user what happened tx_ok = status & _BV(TX_DS); tx_fail = status & _BV(MAX_RT); rx_ready = status & _BV(RX_DR); } /****************************************************************************/ void RF24::openWritingPipe(uint64_t value) { // Note that AVR 8-bit uC's store this LSB first, and the NRF24L01(+) // expects it LSB first too, so we're good. write_register(RX_ADDR_P0, reinterpret_cast<uint8_t*>(&value), 5); write_register(TX_ADDR, reinterpret_cast<uint8_t*>(&value), 5); const uint8_t max_payload_size = 32; write_register(RX_PW_P0,min(payload_size,max_payload_size)); flush_tx(); } /****************************************************************************/ static const uint8_t child_pipe[] = { RX_ADDR_P0, RX_ADDR_P1, RX_ADDR_P2, RX_ADDR_P3, RX_ADDR_P4, RX_ADDR_P5 }; static const uint8_t child_payload_size[] = { RX_PW_P0, RX_PW_P1, RX_PW_P2, RX_PW_P3, RX_PW_P4, RX_PW_P5 }; static const uint8_t child_pipe_enable[] = { ERX_P0, ERX_P1, ERX_P2, ERX_P3, ERX_P4, ERX_P5 }; void RF24::openReadingPipe(uint8_t child, uint64_t address) { // If this is pipe 0, cache the address. This is needed because // openWritingPipe() will overwrite the pipe 0 address, so // startListening() will have to restore it. if (child == 0) pipe0_reading_address = address; if (child <= 6) { // For pipes 2-5, only write the LSB if ( child < 2 ) write_register(child_pipe[child], reinterpret_cast<const uint8_t*>(&address), 5); else write_register(child_pipe[child], reinterpret_cast<const uint8_t*>(&address), 1); write_register(child_payload_size[child],payload_size); // Note it would be more efficient to set all of the bits for all open // pipes at once. However, I thought it would make the calling code // more simple to do it this way. write_register(EN_RXADDR,read_register(EN_RXADDR) | _BV(child_pipe_enable[child])); } } /****************************************************************************/ void RF24::toggle_features(void) { csn(LOW); spi.write( ACTIVATE ); spi.write( 0x73 ); csn(HIGH); } /****************************************************************************/ void RF24::enableDynamicPayloads(void) { // Enable dynamic payload throughout the system write_register(FEATURE,read_register(FEATURE) | _BV(EN_DPL) ); // If it didn't work, the features are not enabled if ( ! read_register(FEATURE) ) { // So enable them and try again toggle_features(); write_register(FEATURE,read_register(FEATURE) | _BV(EN_DPL) ); } // IF_SERIAL_DEBUG(printf("FEATURE=%i\r\n",read_register(FEATURE))); // Enable dynamic payload on all pipes // // Not sure the use case of only having dynamic payload on certain // pipes, so the library does not support it. write_register(DYNPD,read_register(DYNPD) | _BV(DPL_P5) | _BV(DPL_P4) | _BV(DPL_P3) | _BV(DPL_P2) | _BV(DPL_P1) | _BV(DPL_P0)); dynamic_payloads_enabled = true; } /****************************************************************************/ void RF24::enableAckPayload(void) { // // enable ack payload and dynamic payload features // write_register(FEATURE,read_register(FEATURE) | _BV(EN_ACK_PAY) | _BV(EN_DPL) ); // If it didn't work, the features are not enabled if ( ! read_register(FEATURE) ) { // So enable them and try again toggle_features(); write_register(FEATURE,read_register(FEATURE) | _BV(EN_ACK_PAY) | _BV(EN_DPL) ); } // IF_SERIAL_DEBUG(printf("FEATURE=%i\r\n",read_register(FEATURE))); // // Enable dynamic payload on pipes 0 & 1 // write_register(DYNPD,read_register(DYNPD) | _BV(DPL_P1) | _BV(DPL_P0)); } /****************************************************************************/ void RF24::writeAckPayload(uint8_t pipe, const void* buf, uint8_t len) { const uint8_t* current = reinterpret_cast<const uint8_t*>(buf); csn(LOW); spi.write( W_ACK_PAYLOAD | ( pipe & 7 ) ); const uint8_t max_payload_size = 32; uint8_t data_len = min(len,max_payload_size); while ( data_len-- ) spi.write(*current++); csn(HIGH); } /****************************************************************************/ bool RF24::isAckPayloadAvailable(void) { bool result = ack_payload_available; ack_payload_available = false; return result; } /****************************************************************************/ bool RF24::isPVariant(void) { return p_variant ; } /****************************************************************************/ void RF24::setAutoAck(bool enable) { if ( enable ) write_register(EN_AA, 63); else write_register(EN_AA, 0); } /****************************************************************************/ void RF24::setAutoAck( uint8_t pipe, bool enable ) { if ( pipe <= 6 ) { uint8_t en_aa = read_register( EN_AA ) ; if( enable ) { en_aa |= _BV(pipe) ; } else { en_aa &= ~_BV(pipe) ; } write_register( EN_AA, en_aa ) ; } } /****************************************************************************/ bool RF24::testCarrier(void) { return ( read_register(CD) & 1 ); } /****************************************************************************/ bool RF24::testRPD(void) { return ( read_register(RPD) & 1 ) ; } /****************************************************************************/ void RF24::setPALevel(rf24_pa_dbm_e level) { uint8_t setup = read_register(RF_SETUP) ; setup &= ~(_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH)) ; // switch uses RAM (evil!) if ( level == RF24_PA_MAX ) { setup |= (_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH)) ; } else if ( level == RF24_PA_HIGH ) { setup |= _BV(RF_PWR_HIGH) ; } else if ( level == RF24_PA_LOW ) { setup |= _BV(RF_PWR_LOW); } else if ( level == RF24_PA_MIN ) { // nothing } else if ( level == RF24_PA_ERROR ) { // On error, go to maximum PA setup |= (_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH)) ; } write_register( RF_SETUP, setup ) ; } /****************************************************************************/ rf24_pa_dbm_e RF24::getPALevel(void) { rf24_pa_dbm_e result = RF24_PA_ERROR ; uint8_t power = read_register(RF_SETUP) & (_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH)) ; // switch uses RAM (evil!) if ( power == (_BV(RF_PWR_LOW) | _BV(RF_PWR_HIGH)) ) { result = RF24_PA_MAX ; } else if ( power == _BV(RF_PWR_HIGH) ) { result = RF24_PA_HIGH ; } else if ( power == _BV(RF_PWR_LOW) ) { result = RF24_PA_LOW ; } else { result = RF24_PA_MIN ; } return result ; } /****************************************************************************/ bool RF24::setDataRate(rf24_datarate_e speed) { bool result = false; uint8_t setup = read_register(RF_SETUP) ; // HIGH and LOW '00' is 1Mbs - our default wide_band = false ; setup &= ~(_BV(RF_DR_LOW) | _BV(RF_DR_HIGH)) ; if( speed == RF24_250KBPS ) { // Must set the RF_DR_LOW to 1; RF_DR_HIGH (used to be RF_DR) is already 0 // Making it '10'. wide_band = false ; setup |= _BV( RF_DR_LOW ) ; } else { // Set 2Mbs, RF_DR (RF_DR_HIGH) is set 1 // Making it '01' if ( speed == RF24_2MBPS ) { wide_band = true ; setup |= _BV(RF_DR_HIGH); } else { // 1Mbs wide_band = false ; } } write_register(RF_SETUP,setup); // Verify our result if ( read_register(RF_SETUP) == setup ) { result = true; } else { wide_band = false; } return result; } /****************************************************************************/ rf24_datarate_e RF24::getDataRate( void ) { rf24_datarate_e result ; uint8_t dr = read_register(RF_SETUP) & (_BV(RF_DR_LOW) | _BV(RF_DR_HIGH)); // switch uses RAM (evil!) // Order matters in our case below if ( dr == _BV(RF_DR_LOW) ) { // '10' = 250KBPS result = RF24_250KBPS ; } else if ( dr == _BV(RF_DR_HIGH) ) { // '01' = 2MBPS result = RF24_2MBPS ; } else { // '00' = 1MBPS result = RF24_1MBPS ; } return result ; } /****************************************************************************/ void RF24::setCRCLength(rf24_crclength_e length) { uint8_t config = read_register(CONFIG) & ~( _BV(CRCO) | _BV(EN_CRC)) ; if ( length == RF24_CRC_DISABLED ) { // Do nothing, we turned it off above. } else if ( length == RF24_CRC_8 ) { config |= _BV(EN_CRC); } else { config |= _BV(EN_CRC); config |= _BV( CRCO ); } write_register( CONFIG, config ) ; } /****************************************************************************/ rf24_crclength_e RF24::getCRCLength(void) { rf24_crclength_e result = RF24_CRC_DISABLED; uint8_t config = read_register(CONFIG) & ( _BV(CRCO) | _BV(EN_CRC)) ; if ( config & _BV(EN_CRC ) ) { if ( config & _BV(CRCO) ) result = RF24_CRC_16; else result = RF24_CRC_8; } return result; } /****************************************************************************/ void RF24::disableCRC( void ) { uint8_t disable = read_register(CONFIG) & ~_BV(EN_CRC) ; write_register( CONFIG, disable ) ; } /****************************************************************************/ void RF24::setRetries(uint8_t delay, uint8_t count) { write_register(SETUP_RETR,(delay&0xf)<<ARD | (count&0xf)<<ARC); } uint8_t RF24::min(uint8_t a, uint8_t b) { if(a < b) return a; else return b; }