From 781deb73f651e910e7427c0943008fe2787463f4 Mon Sep 17 00:00:00 2001
From: Marvin Blum <marvin@marvinblum.de>
Date: Sun, 16 Apr 2017 02:31:02 +0200
Subject: [PATCH] Started rf24 with SPI.

---
 compile         |  1 +
 main.c          | 24 +++++--------
 rf24/nRF24L01.h | 26 ++++++++++++++
 rf24/rf24.c     | 91 +++++++++++++++++++++++++++++++++++++++++++++++++
 rf24/rf24.h     | 16 +++++++++
 5 files changed, 142 insertions(+), 16 deletions(-)
 create mode 100644 rf24/nRF24L01.h
 create mode 100644 rf24/rf24.c
 create mode 100644 rf24/rf24.h

diff --git a/compile b/compile
index 4ab5a2e..8064098 100755
--- a/compile
+++ b/compile
@@ -4,6 +4,7 @@ mkdir build
 avr-gcc -Os -DF_CPU=16000000UL -mmcu=atmega328p -c -o build/util.o -Wall ard/util.c
 avr-gcc -Os -DF_CPU=16000000UL -mmcu=atmega328p -c -o build/serial.o -Wall ard/serial.c
 avr-gcc -Os -DF_CPU=16000000UL -mmcu=atmega328p -c -o build/pins.o -Wall ard/pins.c
+avr-gcc -Os -DF_CPU=16000000UL -mmcu=atmega328p -c -o build/rf24.o -Wall rf24/rf24.c
 avr-gcc -Os -DF_CPU=16000000UL -mmcu=atmega328p -c -o build/main.o -Wall main.c
 avr-gcc -mmcu=atmega328p build/*.o -o build/main
 avr-objcopy -O ihex -R .eeprom build/main build/main.hex
diff --git a/main.c b/main.c
index 0616d88..390b900 100644
--- a/main.c
+++ b/main.c
@@ -1,7 +1,10 @@
+#include <util/delay.h>
 #include <stdio.h>
 #include "ard/serial.h"
 #include "ard/pins.h"
 #include "ard/util.h"
+#include "rf24/rf24.h"
+#include "rf24/nRF24L01.h"
 
 void prepare();
 void loop();
@@ -19,23 +22,12 @@ void prepare(){
 	pins_init();
 	serial_init(9600);
 
-	pin_mode(A1, INPUT);
-	pin_mode(6, OUTPUT);
-	pin_mode(11, OUTPUT);
+	_delay_ms(50);
+	rf24_init(7, 6, 5, 4, 3, 2);
+	_delay_ms(200);
 }
 
 void loop(){
-	int analog = map(analog_read(A1), 0, 1023, 0, 255);
-	analog_write(11, analog);
-
-	if(analog < 128){
-		digital_write(6, HIGH);
-	}
-	else{
-		digital_write(6, LOW);
-	}
-
-	char out[15];
-	sprintf(out, "%d", analog);
-	serial_write(out, 15);
+	rf24_read_register(STATUS);
+	_delay_ms(5);
 }
diff --git a/rf24/nRF24L01.h b/rf24/nRF24L01.h
new file mode 100644
index 0000000..bb5e445
--- /dev/null
+++ b/rf24/nRF24L01.h
@@ -0,0 +1,26 @@
+#ifndef NRF24L01_H_
+#define NRF24L01_H_
+
+#define CONFIG      0x00
+#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 STATUS      0x07
+#define RX_DR       6
+#define TX_DS       5
+#define MAX_RT      4
+#define RX_P_NO     3 // 3 bits
+#define TX_FULL     0
+
+#define R_REGISTER  0x00
+#define W_REGISTER  0x20
+#define REG_MASK    0x1f
+
+// TODO
+
+#endif
diff --git a/rf24/rf24.c b/rf24/rf24.c
new file mode 100644
index 0000000..53ae2b4
--- /dev/null
+++ b/rf24/rf24.c
@@ -0,0 +1,91 @@
+#include "rf24.h"
+#include "nRF24L01.h"
+#include "../ard/pins.h"
+
+// FIXME for testing, remove later
+#include <util/delay.h>
+
+const unsigned char RF24_POWER_DOWN = 1;
+const unsigned char RF24_STANDBY_1 = 2;
+const unsigned char RF24_STANDBY_2 = 3;
+const unsigned char RF24_TX = 4;
+const unsigned char RF24_RX = 5;
+
+unsigned char _ce, _csn, _sck, _mo, _mi, _irq;
+
+unsigned char rf24_serial_write(unsigned char);
+
+void rf24_init(unsigned char ce, unsigned char csn, unsigned char sck, unsigned char mo, unsigned char mi, unsigned char irq){
+	pin_mode(ce, OUTPUT);
+	pin_mode(csn, OUTPUT);
+	digital_write(csn, HIGH); // disable
+	pin_mode(sck, OUTPUT);
+	pin_mode(mo, OUTPUT);
+	pin_mode(mi, INPUT);
+	pin_mode(irq, OUTPUT);
+
+	_ce = ce;
+	_csn = csn;
+	_sck = sck;
+	_mo = mo;
+	_mi = mi;
+	_irq = irq;
+
+	rf24_mode(RF24_POWER_DOWN);
+}
+
+void rf24_mode(unsigned char mode){
+	switch(mode){
+		case 1: // RF24_POWER_DOWN
+			rf24_config_register(CONFIG, 0x00);
+			break;
+		case 2: // RF24_STANDBY_1
+			//rf24_config_register(CONFIG, 1<<PWR_UP);
+			break;
+		case 3: // RF24_STANDBY_2
+			break;
+		case 4: // RF24_TX
+			break;
+		case 5: // RF24_RX
+			break;
+	}
+}
+
+void rf24_config_register(unsigned char reg, unsigned char value){
+	rf24_serial_write(W_REGISTER|(reg&REG_MASK));
+	rf24_serial_write(value);
+}
+
+unsigned char rf24_read_register(unsigned char reg){
+	return rf24_serial_write(R_REGISTER|(reg&REG_MASK));
+}
+
+unsigned char rf24_serial_write(unsigned char data){
+	digital_write(_sck, LOW);
+	digital_write(_csn, LOW); // chip enable
+	unsigned char i = 0, rx = 0;
+
+	for(i = 0; i < 8; i++){
+		// write bit
+		if(data&(1<<(7-i))){
+			digital_write(_mo, HIGH);
+		}
+		else{
+			digital_write(_mo, LOW);
+		}
+
+		// read bit
+		digital_write(_sck, HIGH); // clock
+		rx <<= 1;
+
+		if(digital_read(_mi)){
+			rx |= 0x01;
+		}
+
+		digital_write(_sck, LOW); // clock
+	}
+
+	digital_write(_csn, HIGH); // chip disable
+
+	return rx;
+}
diff --git a/rf24/rf24.h b/rf24/rf24.h
new file mode 100644
index 0000000..c2a58fc
--- /dev/null
+++ b/rf24/rf24.h
@@ -0,0 +1,16 @@
+#ifndef RF24_H_
+#define RF24_H_
+
+extern const unsigned char RF24_POWER_DOWN;
+extern const unsigned char RF24_STANDBY_1;
+extern const unsigned char RF24_STANDBY_2;
+extern const unsigned char RF24_TX;
+extern const unsigned char RF24_RX;
+
+void rf24_init(unsigned char, unsigned char, unsigned char, unsigned char, unsigned char, unsigned char);
+void rf24_mode(unsigned char);
+
+void rf24_config_register(unsigned char, unsigned char);
+unsigned char rf24_read_register(unsigned char);
+
+#endif