/*
* ----------------------------------------------------------------------------
* “THE COFFEEWARE LICENSE” (Revision 1):
* <ihsan@kehribar.me> wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you think
* this stuff is worth it, you can buy me a coffee in return.
* -----------------------------------------------------------------------------
* This library is based on this library: 
*   https://github.com/aaronds/arduino-nrf24l01
* Which is based on this library: 
*   http://www.tinkerer.eu/AVRLib/nRF24L01
* -----------------------------------------------------------------------------
*/
#ifndef NRF24
#define NRF24

#include <stdint.h>
#include <avr/io.h>

#ifdef TURTLE
#define NRF24_IO_PORT   PORTB
#define NRF24_IO_PINREG PINB
#define NRF24_IO_DDR    DDRB
#else
#define NRF24_IO_PORT   PORTC
#define NRF24_IO_PINREG PINC
#define NRF24_IO_DDR    DDRC
#endif


#define NRF24_CE_PIN   0
#define NRF24_CSN_PIN  1
#define NRF24_SCK_PIN  2
#define NRF24_MOSI_PIN 3
#define NRF24_MISO_PIN 4


/* IO Helpers */
#define nrf24_set_bit(reg,bit) reg |= (1<<bit)
#define nrf24_clr_bit(reg,bit) reg &= ~(1<<bit)
#define nrf24_check_bit(reg,bit) (reg&(1<<bit))

/* Memory Map */
#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

/* Bit Mnemonics */

/* configuratio nregister */
#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

/* enable auto acknowledgment */
#define ENAA_P5     5
#define ENAA_P4     4
#define ENAA_P3     3
#define ENAA_P2     2
#define ENAA_P1     1
#define ENAA_P0     0

/* enable rx addresses */
#define ERX_P5      5
#define ERX_P4      4
#define ERX_P3      3
#define ERX_P2      2
#define ERX_P1      1
#define ERX_P0      0

/* setup of address width */
#define AW          0 /* 2 bits */

/* setup of auto re-transmission */
#define ARD         4 /* 4 bits */
#define ARC         0 /* 4 bits */

/* RF setup register */
#define PLL_LOCK    4
#define RF_DR       3
#define RF_PWR      1 /* 2 bits */

/* general status register */
#define RX_DR       6
#define TX_DS       5
#define MAX_RT      4
#define RX_P_NO     1 /* 3 bits */
#define TX_FULL     0

/* transmit observe register */
#define PLOS_CNT    4 /* 4 bits */
#define ARC_CNT     0 /* 4 bits */

/* fifo status */
#define TX_REUSE    6
#define FIFO_FULL   5
#define TX_EMPTY    4
#define RX_FULL     1
#define RX_EMPTY    0

/* dynamic length */
#define DPL_P0      0
#define DPL_P1      1
#define DPL_P2      2
#define DPL_P3      3
#define DPL_P4      4
#define DPL_P5      5

/* Instruction Mnemonics */
#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

#define LOW 0
#define HIGH 1

#define nrf24_ADDR_LEN 5
#define nrf24_CONFIG ((1<<EN_CRC)|(0<<CRCO))

#define NRF24_TRANSMISSON_OK 0
#define NRF24_MESSAGE_LOST   1

/* IO functions */
void nrf24_setupPins();
void nrf24_ce_digitalWrite(uint8_t state);
void nrf24_csn_digitalWrite(uint8_t state);
void nrf24_sck_digitalWrite(uint8_t state);
void nrf24_mosi_digitalWrite(uint8_t state);
uint8_t nrf24_miso_digitalRead();

/* adjustment functions */
void    nrf24_init();
void    nrf24_rx_address(uint8_t* adr);
void    nrf24_tx_address(uint8_t* adr);
void    nrf24_config(uint8_t channel, uint8_t pay_length);

/* state check functions */
uint8_t nrf24_dataReady();
uint8_t nrf24_isSending();
uint8_t nrf24_getStatus();
uint8_t nrf24_rxFifoEmpty();

/* core TX / RX functions */
void    nrf24_send(uint8_t* value);
void    nrf24_getData(uint8_t* data);

/* use in dynamic length mode */
uint8_t nrf24_payloadLength();

/* post transmission analysis */
uint8_t nrf24_lastMessageStatus();
uint8_t nrf24_retransmissionCount();

/* Returns the payload length */
uint8_t nrf24_payload_length();

/* power management */
void    nrf24_powerUpRx();
void    nrf24_powerUpTx();
void    nrf24_powerDown();

/* low level interface ... */
uint8_t spi_transfer(uint8_t tx);
void    nrf24_transmitSync(uint8_t* dataout,uint8_t len);
void    nrf24_transferSync(uint8_t* dataout,uint8_t* datain,uint8_t len);
void    nrf24_configRegister(uint8_t reg, uint8_t value);
void    nrf24_readRegister(uint8_t reg, uint8_t* value, uint8_t len);
void    nrf24_writeRegister(uint8_t reg, uint8_t* value, uint8_t len);

/* -------------------------------------------------------------------------- */
/* You should implement the platform spesific functions in your code */
/* -------------------------------------------------------------------------- */

/* -------------------------------------------------------------------------- */
/* In this function you should do the following things:
 *    - Set MISO pin input
 *    - Set MOSI pin output
 *    - Set SCK pin output
 *    - Set CSN pin output
 *    - Set CE pin output     */
/* -------------------------------------------------------------------------- */
extern void nrf24_setupPins();

/* -------------------------------------------------------------------------- */
/* nrf24 CE pin control function
 *    - state:1 => Pin HIGH
 *    - state:0 => Pin LOW     */
/* -------------------------------------------------------------------------- */
extern void nrf24_ce_digitalWrite(uint8_t state);

/* -------------------------------------------------------------------------- */
/* nrf24 CE pin control function
 *    - state:1 => Pin HIGH
 *    - state:0 => Pin LOW     */
/* -------------------------------------------------------------------------- */
extern void nrf24_csn_digitalWrite(uint8_t state);

/* -------------------------------------------------------------------------- */
/* nrf24 SCK pin control function
 *    - state:1 => Pin HIGH
 *    - state:0 => Pin LOW     */
/* -------------------------------------------------------------------------- */
extern void nrf24_sck_digitalWrite(uint8_t state);

/* -------------------------------------------------------------------------- */
/* nrf24 MOSI pin control function
 *    - state:1 => Pin HIGH
 *    - state:0 => Pin LOW     */
/* -------------------------------------------------------------------------- */
extern void nrf24_mosi_digitalWrite(uint8_t state);

/* -------------------------------------------------------------------------- */
/* nrf24 MISO pin read function
/* - returns: Non-zero if the pin is high */
/* -------------------------------------------------------------------------- */
extern uint8_t nrf24_miso_digitalRead();

#endif