diff options
Diffstat (limited to 'nrf24l01.h')
| -rw-r--r-- | nrf24l01.h | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/nrf24l01.h b/nrf24l01.h new file mode 100644 index 0000000..95d3f48 --- /dev/null +++ b/nrf24l01.h @@ -0,0 +1,160 @@ +#ifndef __NRF24L01__H +#define __NRF24L01__H + +#include <unistd.h> +#include <avr/io.h> +#include <util/delay.h> +#include "spi.h" + +#define PORT_NRF24L01 PORTB +#define DDR_NRF24L01 DDRB +#define DD_CE DDB1 +#define DD_IRQ DDB0 + +#define NRF24L01_CMD_R_REGISTER 0x00 +#define NRF24L01_CMD_W_REGISTER 0x20 +#define NRF24L01_CMD_R_RX_PAYLOAD 0x61 +#define NRF24L01_CMD_W_TX_PAYLOAD 0xA0 +#define NRF24L01_CMD_NOP 0xFF +#define NRF24L01_CMD_FLUSH_TX 0xE1 + +#define NRF24L01_REG_STATUS 0x07 +#define NRF24L01_REG_STATUS_RX_DR 0x06 +#define NRF24L01_REG_STATUS_TX_DS 0x05 +#define NRF24L01_REG_STATUS_MAX_RT 0x04 +#define NRF24L01_REG_RX_PW_P0 0x11 +#define NRF24L01_REG_EN_AA 0x01 +#define NRF24L01_REG_SETUP_RETR 0x04 +#define NRF24L01_REG_CONFIG 0x00 +#define NRF24L01_REG_CONFIG_EN_CRC 0x3 +#define NRF24L01_REG_CONFIG_PWR_UP 0x1 +#define NRF24L01_REG_CONFIG_PRIM_RX 0x0 + +#define MAX_PAYLOAD_IN_BYTES 1 + +static inline void nrf24l01_ce_high() +{ + PORT_NRF24L01 |= _BV(DD_CE); +} + +static inline void nrf24l01_ce_low() +{ + PORT_NRF24L01 &= ~_BV(DD_CE); +} + +static inline uint8_t nrf24l01_read_cmd(uint8_t cmd) +{ + return spi_two_byte(cmd, NRF24L01_CMD_NOP); +} + +static inline uint8_t nrf24l01_read_reg(uint8_t reg) +{ + return nrf24l01_read_cmd(NRF24L01_CMD_R_REGISTER | reg); +} + +static inline void nrf24l01_write_cmd(uint8_t cmd, uint8_t data) +{ + spi_two_byte(cmd, data); +} + +static inline void nrf24l01_write_reg(uint8_t reg, uint8_t data) +{ + nrf24l01_write_cmd(NRF24L01_CMD_W_REGISTER | reg, data); +} + +static inline void nrf24l01_power_up() +{ + uint8_t config = nrf24l01_read_reg(NRF24L01_REG_CONFIG); + nrf24l01_write_reg(NRF24L01_REG_CONFIG, config | _BV(NRF24L01_REG_CONFIG_PWR_UP)); + _delay_us(10); +} + +static inline void nrf24l01_power_down() +{ + uint8_t config = nrf24l01_read_reg(NRF24L01_REG_CONFIG); + nrf24l01_write_reg(NRF24L01_REG_CONFIG, config & ~_BV(NRF24L01_REG_CONFIG_PWR_UP)); +} + +static inline void nrf24l01_init() +{ + spi_init(); + + //nrf24l01_write_reg(NRF24L01_REG_SETUP_RETR, 0x00); + //nrf24l01_write_reg(NRF24L01_REG_EN_AA, 0x00); + nrf24l01_write_reg(NRF24L01_REG_RX_PW_P0, MAX_PAYLOAD_IN_BYTES); + nrf24l01_ce_low(); +} + +static inline void nrf24l01_receive_mode() +{ + uint8_t config = nrf24l01_read_reg(NRF24L01_REG_CONFIG); + nrf24l01_write_reg(NRF24L01_REG_CONFIG, config | _BV(NRF24L01_REG_CONFIG_PRIM_RX)); + nrf24l01_ce_high(); + _delay_us(200); +} + +static inline void nrf24l01_transmit_mode() +{ + uint8_t config = nrf24l01_read_reg(NRF24L01_REG_CONFIG); + config &= ~_BV(NRF24L01_REG_CONFIG_PRIM_RX); + + nrf24l01_ce_low(); + nrf24l01_write_reg(NRF24L01_REG_CONFIG, config); + nrf24l01_ce_high(); + _delay_us(15); + nrf24l01_ce_low(); + _delay_us(200); +} + +static inline uint8_t is_data_received() +{ + uint8_t status = nrf24l01_read_reg(NRF24L01_REG_STATUS); + return status & _BV(NRF24L01_REG_STATUS_RX_DR); +} + +static inline uint8_t nrf24l01_receive_byte() +{ + return nrf24l01_read_cmd(NRF24L01_CMD_R_RX_PAYLOAD); +} + +static inline uint8_t is_data_transmitted(uint8_t status) +{ + return status & _BV(NRF24L01_REG_STATUS_TX_DS); +} + +static inline uint8_t is_data_transmit_failed(uint8_t status) +{ + return status & _BV(NRF24L01_REG_STATUS_MAX_RT); +} + +static inline int nrf24l01_send_byte(uint8_t data) +{ + nrf24l01_write_cmd(NRF24L01_CMD_W_TX_PAYLOAD, data); + nrf24l01_transmit_mode(); + + uint8_t status; + uint8_t err = 0; + + while (1) { + status = nrf24l01_read_reg(NRF24L01_REG_STATUS); + + if(is_data_transmitted(status)) { + nrf24l01_write_reg(NRF24L01_REG_STATUS, status); + break; + } + + if(is_data_transmit_failed(status)) { + nrf24l01_write_cmd(NRF24L01_CMD_FLUSH_TX, NRF24L01_CMD_NOP); + err = 1; + break; + } + + _delay_us(10000); + } + + nrf24l01_write_reg(NRF24L01_REG_STATUS, status); + nrf24l01_receive_mode(); + return err; +} + +#endif // NRF24L01__H |