Started working on RF24.

rf24/register.h

@@ -0,0 +1,93 @@
+// DO NOT INCLUDE THIS!
+// INCLUDE rf24.h INSTEAD!
+
+#define CONFIG      0x00
+#define EN_AA       0x01
+#define EN_RXADDR   0x02
+#define SETUP_AW    0x03
+#define SETUP_RETR  0x04
+#define RF_CH       0x05
+#define RF_SETUP    0x06
+#define STATUS      0x07
+#define OBSERVE_TX  0x08
+#define CD          0x09
+#define RX_ADDR_P0  0x0A
+#define RX_ADDR_P1  0x0B
+#define RX_ADDR_P2  0x0C
+#define RX_ADDR_P3  0x0D
+#define RX_ADDR_P4  0x0E
+#define RX_ADDR_P5  0x0F
+#define TX_ADDR     0x10
+#define RX_PW_P0    0x11
+#define RX_PW_P1    0x12
+#define RX_PW_P2    0x13
+#define RX_PW_P3    0x14
+#define RX_PW_P4    0x15
+#define RX_PW_P5    0x16
+#define FIFO_STATUS 0x17
+#define DYNPD       0x1C
+
+#define MASK_RX_DR  6
+#define MASK_TX_DS  5
+#define MASK_MAX_RT 4
+#define EN_CRC      3
+#define CRCO        2
+#define PWR_UP      1
+#define PRIM_RX     0
+
+#define ENAA_P5     5
+#define ENAA_P4     4
+#define ENAA_P3     3
+#define ENAA_P2     2
+#define ENAA_P1     1
+#define ENAA_P0     0
+
+#define ERX_P5      5
+#define ERX_P4      4
+#define ERX_P3      3
+#define ERX_P2      2
+#define ERX_P1      1
+#define ERX_P0      0
+
+#define AW          0 // 2 bits
+
+#define ARD         4 // 4 bits
+#define ARC         0 // 4 bits
+
+#define PLL_LOCK    4
+#define RF_DR       3
+#define RF_PWR      1 // 2 bits
+
+#define RX_DR       6
+#define TX_DS       5
+#define MAX_RT      4
+#define RX_P_NO     1 // 3 bits
+#define TX_FULL     0
+
+#define PLOS_CNT    4 // 4 bits
+#define ARC_CNT     0 // 4 bits
+
+#define TX_REUSE    6
+#define FIFO_FULL   5
+#define TX_EMPTY    4
+#define RX_FULL     1
+#define RX_EMPTY    0
+
+#define DPL_P0      0
+#define DPL_P1      1
+#define DPL_P2      2
+#define DPL_P3      3
+#define DPL_P4      4
+#define DPL_P5      5
+
+#define R_REGISTER    0x00 // last 4 bits will indicate reg. address
+#define W_REGISTER    0x20 // last 4 bits will indicate reg. address
+#define REGISTER_MASK 0x1F
+#define R_RX_PAYLOAD  0x61
+#define W_TX_PAYLOAD  0xA0
+#define FLUSH_TX      0xE1
+#define FLUSH_RX      0xE2
+#define REUSE_TX_PL   0xE3
+#define ACTIVATE      0x50 
+#define R_RX_PL_WID   0x60
+#define NOP           0xFF

rf24/rf24.c

@@ -0,0 +1,89 @@
+#include "rf24.h"
+#include "../ard/pins.h"
+
+// CE = standby mode, CSN = SPI chip select
+char payload_len, spi_ce, spi_csn, spi_sck, spi_mosi, spi_miso;
+
+void reg_write(unsigned char, unsigned char);
+void spi_transfer(unsigned char);
+
+void rf24_init(unsigned char payload_length,
+	unsigned char channel,
+	unsigned char ce,
+	unsigned char csn,
+	unsigned char sck,
+	unsigned char mosi,
+	unsigned char miso){
+	if(payload_length > 32){
+		payload_length = 32;
+	}
+
+	payload_len = payload_length;
+	spi_ce = ce;
+	spi_csn = csn;
+	spi_sck = sck;
+	spi_mosi = mosi;
+	spi_miso = miso;
+
+	pin_mode(spi_ce, OUTPUT);
+	pin_mode(spi_csn, OUTPUT);
+	pin_mode(spi_sck, OUTPUT);
+	pin_mode(spi_mosi, OUTPUT);
+	pin_mode(spi_miso, INPUT);
+
+	digital_write(spi_ce, LOW);
+	digital_write(spi_csn, HIGH);
+
+	reg_write(RF_CH, channel);
+}
+
+void rf24_tx_addr(unsigned char* addr){
+
+}
+
+void rf24_rx_addr(unsigned char* addr){
+
+}
+
+void rf24_send(char* data){
+
+}
+
+void rf24_receive(char* data){
+
+}
+
+void reg_write(unsigned char reg, unsigned char value){
+	digital_write(spi_csn, LOW);
+	spi_transfer(W_REGISTER|(REGISTER_MASK&reg));
+	spi_transfer(value);
+	digital_write(spi_csn, HIGH);
+}
+
+void spi_transfer(unsigned char data){
+	unsigned char i = 0;
+	unsigned char rx = 0;
+
+	digital_write(spi_sck, LOW); // clock
+
+	for(i = 0; i < 8; i++){
+		// tx
+		if(data&(1<<(7-i))){
+			digital_write(spi_mosi, HIGH);
+		}
+		else{
+			digital_write(spi_mosi, LOW);
+		}
+
+		digital_write(spi_sck, HIGH); // clock
+
+		// rx
+		rx <<= 1;
+
+		if(digital_read(spi_miso) == HIGH){
+			rx |= 0x01;
+		}
+
+		digital_write(spi_sck, LOW); // clock
+	}
+}

rf24/rf24.h

@@ -0,0 +1,12 @@
+#ifndef RF24_H_
+#define RF24_H_
+
+#include "register.h"
+
+void rf24_init(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char);
+void rf24_tx_addr(unsigned char*);
+void rf24_rx_addr(unsigned char*);
+void rf24_send(char*); // length is fixed and set on initialization
+void rf24_receive(char*); // length is fixed and set on initialization
+
+#endif