No he trabajado nunca con el nrf24l01, pero si lo he hecho con el nrf905 y recuerdo que no logré que funcionara con las funciones nativas de spi del CCS. Conseguí que funcionara utilizando las funciones spi por software, lamentablemente no dispongo del código que he utilizado pues me encuentro de viaje y no regreso a mi domicilio en Barcelona hasta diciembre.
He encontrado un código parecido al código en que me basé. Las funciones spi están al final:
void spiWrite(INT8U dat)
INT8U spiRead(void)
#include <htc.h>
#include "delay.h"
#include "nRF905.h"
/*
****************************************************************************************
* Instruction set for the nRF905 SPI interface; refer to page 16 of nRF905 datasheet
* The available commands to be used on the SPI interface is shown below. Whenever
* CSN is set low the interface expects an instruction. Every new instruction must be
* started by a high to low transition on CSN.
* A read or a write operation may operate on a single byte or on a set of succeeding
* bytes from a given start address defined by the instruction.
****************************************************************************************
*/
#define WRC 0x00 //Write configuration register command
#define RRC 0x10 //Read configuration register command
#define WTP 0x20 //Wrte TX Payload command
#define RTP 0x21 //Read TX Payload command
#define WTA 0x22 //Write TX Address command
#define RTA 0x23 //Read TX address command
#define RRP 0x24 //Read RX Payload command
#define CC 0x80 //Channel configuration
#define OUTPUT 0
#define INPUT 1
#define HIGH 1
#define LOW 0
typedef struct _RFconfig
{
INT8U n;
INT8U buf[10]; //RF-CONFIG REGISTER (refer to page 20 of nRF905 datasheet)
}RFconfig;
/*
* Initialization of the Register Contents at byte# 0 - 9 as stated on page 20 of nRF905 datasheet
*/
const RFconfig RxTxconfig =
{
10,
0x01, //byte# 0 : set the channel # to 1
0x0e, //byte# 1 : 0bxx[AUTO_RETRAN<5>][RX_RED_PWR<4>][PA_PWR<3:2>][HFREQ_PLL<1>][CH_NO[8]<0>]
// 0b00001100 => AUTO_RETRAN=0; No retransmission of data packet
// RX_RED_PWR=0; Normal operation
// PA_PWR=11; +10dBm output power
// HFREQ_PLL=1; chip operating in 868 MHz band
// CH_NO[8]=0; 9th bit of CH_NO is zero
0x44, //byte# 2 : TX_AFW[2:0]=100 => 4 byte TX address field width
// RX_AFW[2:0]=100 => 4 byte RX address field width
0x20, //byte# 3 : RX_payload width of 32 bytes
0x20, //byte# 4 : TX_payload width of 32 bytes
0xcc, //byte# 5 : RX_ADDRESS byte 0
0xcc, //byte# 6 : RX_ADDRESS byte 1
0xcc, //byte# 7 : RX_ADDRESS byte 2
0xcc, //byte# 8 : RX_ADDRESS byte 3; thus the RX ADDRESS is configured to 0xcccccccc in this example
//remarks : The default value is 0xE7E7E7E7
0x58 //byte# 9 : Set the CRC_MODE, CRC_EN, XOF[2:0], UP_CLK_EN, UP_CLK_FREQ[1:0] bit values
// In this configuration, we are doing CRC enable for 8 CRC check bit, 16MHz crystal freq,
// and output clock disable
};
/*
**********************************************************************************************************
void rfSetChannel(void)
{
static INT8U tmp;
RACSN = LOW;
spiWrite(RRC|0x01); //read the configuration address starting address 1
tmp = spiRead()&0xfc; //clear the relevant HFREQ_PLL and CH_NO[8] bits
RACSN = HIGH;
RACSN = LOW;
spiWrite(WRC); //write the configuration register starting from address 0
spiWrite((INT8U)CHANNEL); //write bit[7:0] of the channel, leaving CH_NO[8] in the second register
spiWrite(tmp|(HFREQ<<1)|((CHANNEL>>8)&0x01));
RACSN = HIGH;
}
**********************************************************************************************************
*/
/* declaration of Tx and Rx buffers */
INT8U TxBuf[32];
INT8U RxBuf[32];
/*
ShockBurst TX routine, send the whole paylod buffer in 32 bytes to a designated receiving node (TX-address)
*/
void rfTxPacket(void)
{
INT8U i;
PWR = HIGH;
TXEN = HIGH;
TRX_CE = LOW;
RACSN = LOW; //chip select
spiWrite(WTA); //write 4 bytes TX-ADDRESS
for(i=0; i<4; i++)
{
spiWrite(RxTxconfig.buf[i+5]);
}
RACSN = HIGH;
for(i=0;i<200;i++);
RACSN = LOW; //chip select
spiWrite(WTP);
for (i=0;i<32;i++)
{
spiWrite(TxBuf[i]); //write payload data here
}
RACSN = HIGH; //chip de-select
TRX_CE = HIGH; //radio enabled
DelayUs(20);
TRX_CE = LOW; //Since no auto-transmit in this example
//TRX_CE set low for standby mode
}
void rfRxPacket(void)
{
INT8U i;
TRX_CE = LOW; //switch to standby mode
RACSN = LOW; //chip select
spiWrite(RRP); //read payload command
for(i=0;i<32;i++)
RxBuf[i] = spiRead();
RACSN = LOW;
while(DR||AM);
TRX_CE=HIGH;
}
void rfConfig905(void)
{
INT8U i;
PWR = HIGH;
TRX_CE = LOW;
RACSN = LOW; //chip enable
spiWrite(WRC); //repeat SPI write
for(i=0;i<RxTxconfig.n;i++)
{
spiWrite(RxTxconfig.buf[i]);
}
RACSN = HIGH; //chip disable
}
void rfSetRxMode(void)
{
/* Set Receive mode */
PWR = HIGH;
TXEN = LOW;
TRX_CE = HIGH;
/* After 650us nRF905 is monitoring the air for incoming communication */
DelayUs(200);
DelayUs(200);
DelayUs(200);
DelayUs(50);
}
void rfInitIO(void)
{
RACSN = HIGH; //de-select the RF module to start with
TRIS_RACSN = OUTPUT;
SPI_SCK = LOW; //clock line low to start with
TRIS_SPI_SCK = OUTPUT;
TRIS_SPI_MOSI = OUTPUT;
TRIS_SPI_MISO = INPUT;
TRIS_PWR = OUTPUT;
TRIS_TRX_CE = OUTPUT;
TRIS_TXEN = OUTPUT;
TRIS_CD = INPUT;
TRIS_AM = INPUT;
TRIS_DR = INPUT;
}
void spiWrite(INT8U dat)
{
/* software SPI, send MSB first */
static INT8U i, c;
c = dat;
for(i=0;i<8;i++)
{
if((c&0x80)==0x80)
SPI_MOSI = HIGH;
else
SPI_MOSI = LOW;
SPI_SCK = HIGH;
c=c<<1;
SPI_SCK = LOW;
}
}
INT8U spiRead(void)
{
/* software SPI read, MSB read first */
static INT8U i, dat;
for(i=0;i<8;i++)
{
dat = dat<<1;
SPI_SCK = HIGH;
if(SPI_MISO)
dat = dat+1;
SPI_SCK = LOW;
}
return dat;
}
void rfSetPwrOff(void)
{
PWR = LOW;
}
Saludos,
Miquel
