/*! * \file onewire_uart.h * \brief * A target independent 1-wire implementation using a microprocessor's uart * for bit timing * \note * This 1-wire implementation is based on MCU UART io functionality. In order * to work it needs: * 1) A Open drain tx and floating(or pull-up) rx UART pin configuration with both pins * connected to the 1-wire bus wire * 2) A Transmit function even in blocking/polling mode * 3) A receive function even in blocking/polling mode * 4) A baudrate set function * * Author: Christos Choutouridis AEM: 8997 * email : * */ #ifndef __onewire_uart_h__ #define __onewire_uart_h__ #ifdef __cplusplus extern "C" { #endif #include "driver_types.h" #include /* ================ General Defines ====================*/ typedef uint16_t (*ow_uart_rw_ft) (uint8_t); /*!< UART read-write function pointer */ typedef drv_status_en (*ow_uart_br_ft) (uint32_t); /*!< UART baudrate modify function pointer */ /*! * 1-Wire operational state */ typedef enum { OWS_RESET = 0, /*!< 1-Wire bus is during in Reset state */ OWS_OPER /*!< 1-Wire bus is during normal operation */ }ow_uart_state_en; /*! * 1-Wire UART baudrate table */ typedef struct { uint32_t reset; /*!< Baudrate during reset */ uint32_t oper; /*!< Baudrate during normal operation */ uint32_t current; /*!< The current baudrate to use as flag */ }ow_uart_br_t; /*! * 1-Wire driver function callback pointers * \note * The function in this structure provided from the low level driver (usually). */ typedef struct { ow_uart_rw_ft rw; /*!< Pointer UART read-write function */ ow_uart_br_ft br; /*!< Pointer to UART baudrate function */ }ow_uart_io_t; /*! * 1-Wire Data type */ typedef struct { ow_uart_io_t io; /*!< Callback pointers and direction state */ uint32_t timing; /*!< The selected timing mode */ ow_uart_br_t baudrate; /*!< The current baudrate configuration */ drv_status_en status; /*!< Toolbox driver status */ }ow_uart_t; /* * ============ Helper Macros ============= */ /*! * 1-Wire speed */ #define OW_UART_T_STANDARD (0) #define OW_UART_T_OVERDRIVE (1) /*! * Check if the timing is a valid \ref ow_uart_timing_en value */ #define _ow_uart_is_timings(_t_) ( ((_t_) == OW_UART_T_STANDARD) || ((_t_) == OW_UART_T_OVERDRIVE) ) /* * Timing Diagram * -------------------------------------------------- * Based on Application Note 214 (www.maxim-ic.com) * * --- ---- - - - ------- * Reset \ / \ X X X / * -------------------- - - - - * RS: | | | | | | | | | | | * bit: st 0 1 2 3 4 5 6 7 st * < ---------- 1024/174 usec -------------> * * 8 bits, no parity, 1 stop * Standard: Overdrive : * BR: 9600, BR: 57600 * TX: 0xF0, TX: 0xF8 * RX: 0xF0 not present RX: 0xF8 not present * less if present less if present * * * --- -------------------------------------- * Write 1 \ / * ---- * RS: | | | | | | | | | | | * bit: st 0 1 2 3 4 5 6 7 st * < ------------- 87/11 usec -------------> * 8 bits, no parity, 1 stop * standard: BR: 115200 Overdrive: BR: 921600 * TX: 0xFF * RX: 0xFF * * --- ------ * Write 0 \ / * ------------------------------------- * RS: | | | | | | | | | | | * bit: st 0 1 2 3 4 5 6 7 st * < ------------- 87/11 usec -------------> * 8 bits, no parity, 1 stop * standard: BR: 115200 Overdrive: BR: 921600 * TX: 0x00 * RX: 0x00 * * --- - - - - - - - - - - - ------ * Read \ / X X X X X X X X X X X X X X X / * ---- - - - - - - - - - - - * RS: | | | | | | | | | | | * bit: st 0 1 2 3 4 5 6 7 st * < ------------- 87/11 usec -------------> * ^ * | * Master sample * * 8 bits, no parity, 1 stop * standard: BR: 115200 Overdrive: BR: 921600 * TX: 0xFF * RX: {1 - 0xFF, 0 - [0x00 - 0xFE] } * */ #define _ow_baudrate_standard(_br_) \ do { \ _br_.reset = 9600; \ _br_.oper = 115200; \ _br_.current = 9600; \ } while (0) #define _ow_baudrate_overdrive(_br_) \ do { \ _br_.reset = 115200; \ _br_.oper = 921600; \ _br_.current = 115200; \ } while (0) /* * ============= PUBLIC ALCD API ============= */ /* * Link and Glue functions */ void ow_uart_link_rw (ow_uart_t *ow, ow_uart_rw_ft tx); /*!< link driver's read-write function */ void ow_uart_link_br (ow_uart_t *ow, ow_uart_br_ft br); /*!< link driver's baudrate function*/ /* * Set functions */ void ow_uart_set_timing (ow_uart_t *ow, uint32_t owt); /*!< set 1-wire timing mode */ /* * User Functions */ void ow_uart_deinit (ow_uart_t *ow); /*!< for compatibility */ drv_status_en ow_uart_init (ow_uart_t *ow); /*!< for compatibility */ drv_status_en ow_uart_reset (ow_uart_t *ow); uint8_t ow_uart_rx (ow_uart_t *ow); void ow_uart_tx (ow_uart_t *ow, byte_t byte); uint8_t ow_uart_rw (ow_uart_t *ow, byte_t byte); drv_status_en ow_uart_search (ow_uart_t *ow, uint8_t *romid); #ifdef __cplusplus } #endif #endif /* #ifndef __onewire_uart_h__ */