/******************************************************************************
*
* File: nrf24l01.c
* 
* Copyright S. Brennen Ball, 2006-2007
* 
* The author provides no guarantees, warantees, or promises, implied or
*	otherwise.  By using this software you agree to indemnify the author
* 	of any damages incurred by using it.
*
*****************************************************************************/

#include "nrf24l01.h"

//Arguments except opt_rx_standby_mode fill the actual register they are named 
//  after. Registers that do not need to be initialized are not included here.
//The argument opt_rx_active_mode is only used if the user is initializing the
//  24L01 as a receiver.  If the argument is false, the receiver will remain in
//  standby mode and not monitor for packets.  If the argument is true, the CE
//  pin will be set and the 24L01 will monitor for packets.  In TX mode, the value
//  of this argument is insignificant.
//If the user wants to leave any 1-byte register in its default state, simply put
//  as that register's argument nrf24l01_<reg>_DEFAULT_VAL, where <reg> is the register
//  name.
//If the user wants to leave any of the 5-byte registers RX_ADDR_P0, RX_ADDR_P1, or 
//  TX_ADDR in its default state, simply put NULL in the argument for that address value.
void nrf24l01_initialize(unsigned char config,
						 unsigned char opt_rx_active_mode,  
						 unsigned char en_aa, 
						 unsigned char en_rxaddr, 
						 unsigned char setup_aw, 
						 unsigned char setup_retr, 
						 unsigned char rf_ch, 
						 unsigned char rf_setup, 
						 unsigned char * rx_addr_p0, 
						 unsigned char * rx_addr_p1, 
						 unsigned char rx_addr_p2, 
						 unsigned char rx_addr_p3, 
						 unsigned char rx_addr_p4, 
						 unsigned char rx_addr_p5, 
						 unsigned char * tx_addr, 
						 unsigned char rx_pw_p0, 
						 unsigned char rx_pw_p1, 
						 unsigned char rx_pw_p2, 
						 unsigned char rx_pw_p3, 
						 unsigned char rx_pw_p4, 
						 unsigned char rx_pw_p5)
{
	unsigned char data[5];

	data[0] = en_aa;
	nrf24l01_write_register(nrf24l01_EN_AA, data, 1);

	data[0] = en_rxaddr;
	nrf24l01_write_register(nrf24l01_EN_RXADDR, data, 1);

	data[0] = setup_aw;
	nrf24l01_write_register(nrf24l01_SETUP_AW, data, 1);

	data[0] = setup_retr;
	nrf24l01_write_register(nrf24l01_SETUP_RETR, data, 1);

	data[0] = rf_ch;
	nrf24l01_write_register(nrf24l01_RF_CH, data, 1);

	data[0] = rf_setup;
	nrf24l01_write_register(nrf24l01_RF_SETUP, data, 1);

	if(rx_addr_p0 != NULL)
		nrf24l01_set_rx_addr(rx_addr_p0, 5, 0);
	else
	{
		data[0] = nrf24l01_RX_ADDR_P0_B0_DEFAULT_VAL;
		data[1] = nrf24l01_RX_ADDR_P0_B1_DEFAULT_VAL;
		data[2] = nrf24l01_RX_ADDR_P0_B2_DEFAULT_VAL;
		data[3] = nrf24l01_RX_ADDR_P0_B3_DEFAULT_VAL;
		data[4] = nrf24l01_RX_ADDR_P0_B4_DEFAULT_VAL;
		
		nrf24l01_set_rx_addr(data, 5, 0);
	}

	if(rx_addr_p1 != NULL)
		nrf24l01_set_rx_addr(rx_addr_p1, 5, 1);
	else
	{
		data[0] = nrf24l01_RX_ADDR_P1_B0_DEFAULT_VAL;
		data[1] = nrf24l01_RX_ADDR_P1_B1_DEFAULT_VAL;
		data[2] = nrf24l01_RX_ADDR_P1_B2_DEFAULT_VAL;
		data[3] = nrf24l01_RX_ADDR_P1_B3_DEFAULT_VAL;
		data[4] = nrf24l01_RX_ADDR_P1_B4_DEFAULT_VAL;
		
		nrf24l01_set_rx_addr(data, 5, 1);
	}

	data[0] = rx_addr_p2;
	nrf24l01_set_rx_addr(data, 1, 2);

	data[0] = rx_addr_p3;
	nrf24l01_set_rx_addr(data, 1, 3);

	data[0] = rx_addr_p4;
	nrf24l01_set_rx_addr(data, 1, 4);

	data[0] = rx_addr_p5;
	nrf24l01_set_rx_addr(data, 1, 5);

	if(tx_addr != NULL)
		nrf24l01_set_tx_addr(tx_addr, 5);
	else
	{
		data[0] = nrf24l01_TX_ADDR_B0_DEFAULT_VAL;
		data[1] = nrf24l01_TX_ADDR_B1_DEFAULT_VAL;
		data[2] = nrf24l01_TX_ADDR_B2_DEFAULT_VAL;
		data[3] = nrf24l01_TX_ADDR_B3_DEFAULT_VAL;
		data[4] = nrf24l01_TX_ADDR_B4_DEFAULT_VAL;
		
		nrf24l01_set_tx_addr(data, 5);
	}

	data[0] = rx_pw_p0;
	nrf24l01_write_register(nrf24l01_RX_PW_P0, data, 1);

	data[0] = rx_pw_p1;
	nrf24l01_write_register(nrf24l01_RX_PW_P1, data, 1);

	data[0] = rx_pw_p2;
	nrf24l01_write_register(nrf24l01_RX_PW_P2, data, 1);

	data[0] = rx_pw_p3;
	nrf24l01_write_register(nrf24l01_RX_PW_P3, data, 1);

	data[0] = rx_pw_p4;
	nrf24l01_write_register(nrf24l01_RX_PW_P4, data, 1);

	data[0] = rx_pw_p5;
	nrf24l01_write_register(nrf24l01_RX_PW_P5, data, 1);

	if((config & nrf24l01_CONFIG_PWR_UP) != 0)
		nrf24l01_power_up_param(opt_rx_active_mode, config);
	else
		nrf24l01_power_down_param(config);
}

//initializes the 24L01 to all default values except the PWR_UP and PRIM_RX bits
//this function also disables the auto-ack feature on the chip (EN_AA register is 0)
//bool rx is true if the device should be a receiver and false if it should be
//  a transmitter.
//unsigned char payload_width is the payload width for pipe 0.  All other pipes
//  are left in their default (disabled) state.
//bool enable_auto_ack controls the auto ack feature on pipe 0.  If true, auto-ack will
//  be enabled.  If false, auto-ack is disabled.
void nrf24l01_initialize_debug(bool rx, unsigned char p0_payload_width, bool enable_auto_ack)
{
	unsigned char config;
	unsigned char en_aa;
	
	config = nrf24l01_CONFIG_DEFAULT_VAL | nrf24l01_CONFIG_PWR_UP;
	
	if(enable_auto_ack != false)
		en_aa = nrf24l01_EN_AA_ENAA_P0;
	else
		en_aa = nrf24l01_EN_AA_ENAA_NONE;
	
	if(rx == true)
		config = config | nrf24l01_CONFIG_PRIM_RX;
		
	nrf24l01_initialize(config, 
						true,
						en_aa, 
						nrf24l01_EN_RXADDR_DEFAULT_VAL, 
						nrf24l01_SETUP_AW_DEFAULT_VAL, 
						nrf24l01_SETUP_RETR_DEFAULT_VAL, 
						nrf24l01_RF_CH_DEFAULT_VAL, 
						nrf24l01_RF_SETUP_DEFAULT_VAL,  
						NULL, 
						NULL, 
						nrf24l01_RX_ADDR_P2_DEFAULT_VAL, 
						nrf24l01_RX_ADDR_P3_DEFAULT_VAL, 
						nrf24l01_RX_ADDR_P4_DEFAULT_VAL, 
						nrf24l01_RX_ADDR_P5_DEFAULT_VAL, 
						NULL, 
						p0_payload_width, 
						nrf24l01_RX_PW_P1_DEFAULT_VAL, 
						nrf24l01_RX_PW_P2_DEFAULT_VAL, 
						nrf24l01_RX_PW_P3_DEFAULT_VAL, 
						nrf24l01_RX_PW_P4_DEFAULT_VAL, 
						nrf24l01_RX_PW_P5_DEFAULT_VAL);
}

//initializes only the CONFIG register and pipe 0's payload width
//the primary purpose of this function is to allow users with microcontrollers with
//  extremely small program memories to still be able to init their 24L01.  This code
//  should have a smaller footprint than the above init functions.
//when using this method, the 24L01 MUST have its default configuration loaded
//  in all registers to work.  It is recommended that the device be reset or
//  have its power cycled immediately before this code is run.
//in normal circumstances, the user should use nrf24l01_initialize() rather than this
//  function, since this function does not set all of the register values.
void nrf24l01_initialize_debug_lite(bool rx, unsigned char p0_payload_width)
{
	unsigned char config;
	
	config = nrf24l01_CONFIG_DEFAULT_VAL;
	
	if(rx != false)
		config |= nrf24l01_CONFIG_PRIM_RX;
		
	nrf24l01_write_register(nrf24l01_RX_PW_P0, &p0_payload_width, 1);
	nrf24l01_power_up_param(true, config);
}

//powers up the 24L01 with all necessary delays
//this function takes the existing contents of the CONFIG register and sets the PWR_UP 
//the argument rx_active_mode is only used if the user is setting up the
//  24L01 as a receiver.  If the argument is false, the receiver will remain in
//  standby mode and not monitor for packets.  If the argument is true, the CE
//  pin will be set and the 24L01 will monitor for packets.  In TX mode, the value
//  of this argument is insignificant.
//note: if the read value of the CONFIG register already has the PWR_UP bit set, this function
//  exits in order to not make an unecessary register write.
void nrf24l01_power_up(bool rx_active_mode)
{
	unsigned char config;
	
	nrf24l01_read_register(nrf24l01_CONFIG, &config, 1);
	
	if((config & nrf24l01_CONFIG_PWR_UP) != 0)
		return;
		
	config |= nrf24l01_CONFIG_PWR_UP;
	
	nrf24l01_write_register(nrf24l01_CONFIG, &config, 1);
	
	delay_us(1500);
	
	if((config & nrf24l01_CONFIG_PRIM_RX) == 0)
		nrf24l01_clear_ce();
	else
	{
		if(rx_active_mode != false)
			nrf24l01_set_ce();
		else
			nrf24l01_clear_ce();
	}
}

//powers up the 24L01 with all necessary delays
//this function allows the user to set the contents of the CONFIG register, but the function
//  sets the PWR_UP bit in the CONFIG register, so the user does not need to.
//the argument rx_active_mode is only used if the user is setting up the
//  24L01 as a receiver.  If the argument is false, the receiver will remain in
//  standby mode and not monitor for packets.  If the argument is true, the CE
//  pin will be set and the 24L01 will monitor for packets.  In TX mode, the value
//  of this argument is insignificant.
void nrf24l01_power_up_param(bool rx_active_mode, unsigned char config)
{
	unsigned char test, test2;
	
	config |= nrf24l01_CONFIG_PWR_UP;
	
	nrf24l01_write_register(nrf24l01_CONFIG, &config, 1);

	delay_us(1500);

	if((config & nrf24l01_CONFIG_PRIM_RX) == 0)
		nrf24l01_clear_ce();
	else
	{
		if(rx_active_mode != false)
			nrf24l01_set_ce();
		else
			nrf24l01_clear_ce();
	}
}

//powers down the 24L01
//this function takes the existing contents of the CONFIG register and simply
//  clears the PWR_UP bit in the CONFIG register.
//note: if the read value of the CONFIG register already has the PWR_UP bit cleared, this 
//  function exits in order to not make an unecessary register write.
void nrf24l01_power_down()
{
	unsigned char config;
	
	nrf24l01_read_register(nrf24l01_CONFIG, &config, 1);
	
	if((config & nrf24l01_CONFIG_PWR_UP) == 0)
		return;
	
	config &= (~nrf24l01_CONFIG_PWR_UP);
	
	nrf24l01_write_register(nrf24l01_CONFIG, &config, 1);

	nrf24l01_clear_ce();
}

//powers down the 24L01
//this function allows the user to set the contents of the CONFIG register, but the function
//  clears the PWR_UP bit in the CONFIG register, so the user does not need to.
void nrf24l01_power_down_param(unsigned char config)
{
	config &= (~nrf24l01_CONFIG_PWR_UP);
	
	nrf24l01_write_register(nrf24l01_CONFIG, &config, 1);

	nrf24l01_clear_ce();
}


//sets up the 24L01 as a receiver with all necessary delays
//this function takes the existing contents of the CONFIG register and sets the PRIM_RX 
//  bit in the CONFIG register.
//if the argument rx_active_mode is false, the receiver will remain in standby mode
//  and not monitor for packets.  If the argument is true, the CE pin will be set 
//  and the 24L01 will monitor for packets.
//note: if the read value of the CONFIG register already has the PRIM_RX bit set, this function
//  exits in order to not make an unecessary register write.
void nrf24l01_set_as_rx(bool rx_active_mode)
{
	unsigned char config;
	unsigned char status;
	
	status = nrf24l01_read_register(0, &config, 1);

	if((config & nrf24l01_CONFIG_PRIM_RX) != 0)
		return;

	config |= nrf24l01_CONFIG_PRIM_RX;
	
	nrf24l01_write_register(nrf24l01_CONFIG, &config, 1);

	if(rx_active_mode != false)
		nrf24l01_set_ce();
	else
		nrf24l01_clear_ce();
}

//sets up the 24L01 as a receiver with all necessary delays
//this function allows the user to set the contents of the CONFIG register, but the function
//  sets the PRIM_RX bit in the CONFIG register, so the user does not need to.