Started working on RF24.

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
+	}
+}