/*
* File: librfm95.h
* Author: torsten.roemer@luniks.net
*
* Created on 30. März 2025
*/
#ifndef LIBRFM_H
#define LIBRFM_H
#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
/* Registers shared by FSK and LoRa mode */
#define RFM_FIFO 0x00
#define RFM_OP_MODE 0x01
#define RFM_FRF_MSB 0x06
#define RFM_FRF_MID 0x07
#define RFM_FRF_LSB 0x08
#define RFM_PA_CONFIG 0x09
#define RFM_PA_RAMP 0x0a
#define RFM_OCP 0x0b
#define RFM_LNA 0x0c
#define RFM_DIO_MAP1 0x40
#define RFM_DIO_MAP2 0x41
#define RFM_VERSION 0x42
/* FSK mode registers */
#define RFM_FSK_BITRATE_MSB 0x02
#define RFM_FSK_BITRATE_LSB 0x03
#define RFM_FSK_FDEV_MSB 0x04
#define RFM_FSK_FDEV_LSB 0x05
#define RFM_FSK_RX_CONFIG 0x0d
#define RFM_FSK_RSSI_CONFIG 0x0e
#define RFM_FSK_RSSI_COLLIS 0x0f
#define RFM_FSK_RSSI_THRESH 0x10
#define RFM_FSK_RSSI_VALUE 0x11
#define RFM_FSK_RX_BW 0x12
#define RFM_FSK_AFC_BW 0x13
#define RFM_FSK_AFC_FEI 0x1a
#define RFM_FSK_PREA_DETECT 0x1f
#define RFM_FSK_RX_TO_RSSI 0x20
#define RFM_FSK_RX_TO_PREA 0x21
#define RFM_FSK_RX_TO_SYNC 0x22
#define RFM_FSK_RX_DELAY 0x23
#define RFM_FSK_OSC 0x24
#define RFM_FSK_PREA_MSB 0x25
#define RFM_FSK_PREA_LSB 0x26
#define RFM_FSK_SYNC_CONFIG 0x27
#define RFM_FSK_SYNC_VAL1 0x28
#define RFM_FSK_SYNC_VAL2 0x29
#define RFM_FSK_SYNC_VAL3 0x2a
#define RFM_FSK_SYNC_VAL4 0x2b
#define RFM_FSK_SYNC_VAL5 0x2c
#define RFM_FSK_SYNC_VAL6 0x2d
#define RFM_FSK_SYNC_VAL7 0x2e
#define RFM_FSK_SYNC_VAL8 0x2f
#define RFM_FSK_PCK_CONFIG1 0x30
#define RFM_FSK_PCK_CONFIG2 0x31
#define RFM_FSK_PAYLOAD_LEN 0x32
#define RFM_FSK_NODE_ADDR 0x33
#define RFM_FSK_CAST_ADDR 0x34
#define RFM_FSK_FIFO_THRESH 0x35
#define RFM_FSK_IMAGE_CAL 0x3b
#define RFM_FSK_TEMP 0x3c
#define RFM_FSK_LOW_BAT 0x3d
#define RFM_FSK_IRQ_FLAGS1 0x3e
#define RFM_FSK_IRQ_FLAGS2 0x3f
/* LoRa mode registers */
#define RFM_LORA_FIFO_ADDR_PTR 0x0d
#define RFM_LORA_FIFO_TX_ADDR 0x0e
#define RFM_LORA_FIFO_RX_ADDR 0x0f
#define RFM_LORA_FIFO_CURR_ADDR 0x10
#define RFM_LORA_IRQ_FLAGS_MASK 0x11
#define RFM_LORA_IRQ_FLAGS 0x12
#define RFM_LORA_RX_BYTES_NB 0x13
#define RFM_LORA_RX_HDR_CNT_MSB 0x14
#define RFM_LORA_RX_HDR_CNT_LSB 0x15
#define RFM_LORA_RX_PCK_CNT_MSB 0x16
#define RFM_LORA_RX_PCK_CNT_LSB 0x17
#define RFM_LORA_MODEM_STAT 0x18
#define RFM_LORA_PCK_SNR 0x19
#define RFM_LORA_PCK_RSSI 0x1a
#define RFM_LORA_RSSI 0x1b
#define RFM_LORA_HOP_CHANNEL 0x1c
#define RFM_LORA_MODEM_CONFIG1 0x1d
#define RFM_LORA_MODEM_CONFIG2 0x1e
#define RFM_LORA_SYMB_TIMEO_LSB 0x1f
#define RFM_LORA_PREA_LEN_MSB 0x20
#define RFM_LORA_PREA_LEN_LSB 0x21
#define RFM_LORA_PAYLD_LEN 0x22
#define RFM_LORA_PAYLD_MAX_LEN 0x23
#define RFM_LORA_HOP_PERIOD 0x24
#define RFM_LORA_FIFO_RX_B_ADDR 0x25
#define RFM_LORA_MODEM_CONFIG3 0x26
/* Values shared by FSK and LoRa mode */
#define RFM_MODE_SLEEP 0x00
#define RFM_MODE_STDBY 0x01
#define RFM_MODE_FS_TX 0x02
#define RFM_MODE_TX 0x03
#define RFM_MODE_FS_RX 0x04
#define RFM_MODE_RX 0x05 // LoRa RXCONTINUOUS
#define RFM_MODE_RXSINGLE 0x06 // LoRa only
#define RFM_MODE_CAD 0x07 // LoRa only
#define RFM_MASK_MODE 0x07
#define RFM_F_STEP 61035
#define RFM_DBM_MIN 2
#define RFM_DBM_MAX 17
#define RFM_PA_MIN 0
#define RFM_PA_MAX 15
#define RFM_PA_OFF 2
/* FSK mode values */
#define RFM_FSK_MSG_SIZE 63
/* LoRa mode values */
// assuming 50/50 for Tx/Rx for now
#define RFM_LORA_MSG_SIZE 128
/**
* Flags for 'PayloadReady'/'RxDone' event.
*/
typedef struct {
bool ready;
bool crc;
uint8_t rssi;
} RxFlags;
/**
* F_CPU dependent delay of 5 milliseconds.
* _delay_ms(5);
*
* @param ms
*/
void _rfmDelay5(void);
/**
* Turns the radio on by pulling its reset pin high.
* PORTB |= (1 << PB0);
*/
void _rfmOn(void);
/**
* Selects the radio to talk to via SPI.
* PORTB &= ~(1 << PB1);
*/
void _rfmSel(void);
/**
* Deselects the radio to talk to via SPI.
* PORTB |= (1 << PB1);
*/
void _rfmDes(void);
/**
* SPI transmits/receives given data/returns it.
*
* @param data
* @return data
*/
uint8_t _rfmTx(uint8_t data);
/**
* Initializes the radio module in FSK or LoRa mode with the given carrier
* frequency in kilohertz and node and brodcast address.
* Returns true on success, false otherwise.
*
* @param freq carrier frequency
* @param node address
* @param broadcast address
* @param lora LoRa or FSK mode
* @return success
*/
bool rfmInit(uint64_t freq, uint8_t node, uint8_t cast, bool lora);
/**
* Reads interrupt flags. Should be called when any interrupt occurs
* on DIO0 or DIO4.
*/
void rfmIrq(void);
/**
* Sets the "Timeout" interrupt flag, allowing to "unlock" a possibly hanging
* wait for either "PayloadReady" or "Timeout" by the radio in FSK mode,
* ignored in LoRa mode.
*/
void rfmTimeout(void);
/**
* Shuts down the radio.
*/
void rfmSleep(void);
/**
* Wakes up the radio.
*/
void rfmWake(void);
/**
* Sets the node address.
*
* @param address
*/
void rfmSetNodeAddress(uint8_t address);
/**
* Sets the output power to -2 to +13 dBm.
* Values outside that range are ignored.
*
* @param dBm ouput power
*/
void rfmSetOutputPower(int8_t dBm);
/**
* Returns the current output power setting in dBm.
*
* @return ouput power
*/
int8_t rfmGetOutputPower(void);
/**
* Sets the radio to receive mode and maps "PayloadReady" to DIO0 and enables
* or disables timeout.
* For FSK mode.
*
* @param timeout enable timeout
*/
void rfmStartReceive(bool timeout);
/**
* Returns true and puts the radio in standby mode if a "PayloadReady"
* interrupt arrived.
* For FSK mode.
*
* @return flags
*/
RxFlags rfmPayloadReady(void);
/**
* Sets the radio in standby mode, puts the payload into the given array
* with the given size, and returns the length of the payload.
* For FSK mode.
*
* @param payload buffer for payload
* @param size of payload buffer
* @return payload bytes actually received
*/
size_t rfmReadPayload(uint8_t *payload, size_t size);
/**
* Waits for "PayloadReady", puts the payload into the given array with the
* given size, enables or disables timeout, and returns the length of the
* payload, or 0 if a timeout occurred.
* For FSK mode.
*
* @param payload buffer for payload
* @param size of payload buffer
* @param timeout enable timeout
* @return payload bytes actually received
*/
size_t rfmReceivePayload(uint8_t *payload, size_t size, bool timeout);
/**
* Transmits up to 63 bytes of the given payload with the given node address.
* For FSK mode.
*
* @param payload to be sent
* @param size of payload
* @param node address
* @return payload bytes actually sent
*/
size_t rfmTransmitPayload(uint8_t *payload, size_t size, uint8_t node);
/**
* Sets the radio in continous receive mode and maps "RxDone" to DIO0.
*/
void rfmLoRaStartRx(void);
/**
* Returns true if a "RxDone" interrupt arrived.
*
* @return flags
*/
RxFlags rfmLoRaRxDone(void);
/**
* Puts the received payload into the given array with the given size,
* and returns the length of the payload.
*
* @param payload buffer for payload
* @param size of payload buffer
* @return payload bytes actually received
*/
size_t rfmLoRaRxRead(uint8_t *payload, size_t size);
/**
* Sets the radio in single receive mode, waits for "RxDone" with timeout,
* puts the payload into the given array with the given size, and returns
* the length of the payload, or 0 if a timeout occurred.
*
* @param payload buffer for payload
* @param size of payload buffer
* @return payload bytes actually received
*/
size_t rfmLoRaRx(uint8_t *payload, size_t size);
/**
* Transmits up to 128 bytes of the given payload.
*
* @param payload to be sent
* @param size of payload
* @return payload bytes actually sent
*/
size_t rfmLoRaTx(uint8_t *payload, size_t size);
#endif /* LIBRFM_H */
