1 /****************************************************************************** 2 * 3 * Copyright (C) 2022-2023 Maxim Integrated Products, Inc. (now owned by 4 * Analog Devices, Inc.), 5 * Copyright (C) 2023-2024 Analog Devices, Inc. 6 * 7 * Licensed under the Apache License, Version 2.0 (the "License"); 8 * you may not use this file except in compliance with the License. 9 * You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, software 14 * distributed under the License is distributed on an "AS IS" BASIS, 15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 16 * See the License for the specific language governing permissions and 17 * limitations under the License. 18 * 19 ******************************************************************************/ 20 21 /** 22 * \file 23 * \brief Magnetic Stripe Reader driver 24 * \details This driver can be used to configure and operate the Magnetic Stripe 25 * Reader. It reads and decodes magnetic stripe data that is encoded 26 * according to the ISO/IEC standard 7811. 27 * \details This file defines the driver API including data types and function 28 * prototypes. 29 */ 30 31 #ifndef LIBRARIES_PERIPHDRIVERS_INCLUDE_MAX32662_MSR_H_ 32 #define LIBRARIES_PERIPHDRIVERS_INCLUDE_MAX32662_MSR_H_ 33 34 #ifdef __cplusplus 35 extern "C" { 36 #endif 37 38 /***** Definitions *****/ 39 40 /// Number of tracks on a card 41 #ifndef MSR_NUM_TRACKS 42 #define MSR_NUM_TRACKS 3 43 #endif 44 45 #define MSR_MAX_SAMPLES 1536 46 47 // Assuming nominal bit density of 210 bpi and 3.375 inch length 48 #define MSR_MAX_RAW_LEN_BITS (709) 49 #define MSR_MAX_RAW_LEN_BYTES ((MSR_MAX_RAW_LEN_BITS + 7) / 8) 50 #define MSR_MAX_RAW_LEN_HALFWORDS ((MSR_MAX_RAW_LEN_BITS + 15) / 16) 51 52 /// Maximum size in bytes of decoded track characters (5-bit min to 8-bit max) 53 #define MSR_MAX_DEC_LEN (MSR_MAX_RAW_LEN_BITS / 5) 54 55 /// Swipe direction: the card was swiped in the forward direction 56 #define MSR_FORWARD 0 57 /// Swipe direction: the card was swiped in the reverse direction 58 #define MSR_REVERSE 1 59 60 /// Error codes 61 #define MSR_ERR_OK 0x00 62 #define MSR_ERR_BAD_LEN 0x01 63 #define MSR_ERR_START_SEN 0x02 64 #define MSR_ERR_END_SEN 0x04 65 #define MSR_ERR_OUTLIER 0x08 66 #define MSR_ERR_PARAM 0x10 67 #define MSR_ERR_LRC 0x40 68 #define MSR_ERR_PARITY 0x80 69 70 /// Structure to contain result of a track decode 71 typedef struct { 72 uint8_t error_code; ///< Error code value 73 uint8_t parity_errs; ///< Number of characters with parity errors 74 uint8_t lrc; ///< LRC check value. A value of '0' indicates a 75 /// successful LRC check. Any other value should be 76 /// considered a failure. 77 uint8_t direction; ///< Swipe direction determined from decode 78 uint8_t len; ///< Number or decoded characters. This does not include 79 /// the sentinels or the LRC. 80 uint16_t speed; 81 uint8_t data[MSR_MAX_DEC_LEN]; ///< The decoded data 82 } msr_decoded_track_t; 83 84 /// MSR sample fields 85 typedef union { 86 struct { 87 uint16_t time : 9; 88 uint16_t amp : 7; 89 }; 90 uint16_t value; 91 } msr_sample_t; 92 93 /// Structure to contain raw MSR samples 94 typedef struct { 95 uint16_t len; 96 msr_sample_t data[MSR_MAX_SAMPLES]; 97 } msr_samples_t; 98 99 /***** Function Prototypes *****/ 100 101 /** 102 * \brief Initializes magnetic card reader hardware 103 * \returns #E_NO_ERROR if everything is successful 104 */ 105 int msr_init(void); 106 107 /** 108 * \brief Initializes specified track 109 * \param track track number (1 to 3) 110 */ 111 void msr_init_track(unsigned int track); 112 113 /** 114 * \brief Enables magnetic card reader 115 * \pre The reader should be initialized by calling msr_init() and then 116 * waiting at least 100 us before calling this function. 117 */ 118 void msr_enable(void); 119 120 /** 121 * \brief Disables magnetic card reader 122 */ 123 void msr_disable(void); 124 125 /** 126 * \brief Task used to execute driver functionality. 127 * \details This function executes the internal driver functionality that 128 * processes MSR events and reads stripe data. This function is used 129 * when MSR interrupt servicing is disabled. 130 * \returns 1 if all tracking reading is complete, 0 otherwise 131 */ 132 int msr_task(void); 133 134 /** 135 * \brief Decodes the specified track of data 136 * \param track track number (1 to 3) 137 * \param decoded_track track decode results 138 * \returns number of characters decoded 139 * \note This function has significant stack usage. 140 */ 141 unsigned int msr_track_decode(unsigned int track, msr_decoded_track_t *decoded_track); 142 143 /** 144 * \brief Registers an application callback function 145 * \details The callback function will be called after completion of the read 146 * of all enabled card tracks 147 * \details Unregistering of the callback can be performed by calling this 148 * function function with a NULL parameter. 149 * \param func application callback function 150 */ 151 void msr_set_complete_callback(void (*func)(void)); 152 153 /** 154 * \brief Retrieves the raw (undecoded) sample data for the specified track 155 * of data 156 * \param track track number (1 to 3) 157 * \param samples pointer to where the sample data will be copied 158 * \returns number of samples retrieved 159 */ 160 unsigned int mcr_get_track_samples(unsigned int track, msr_samples_t *samples); 161 162 #ifdef __cplusplus 163 } 164 #endif 165 166 #endif // LIBRARIES_PERIPHDRIVERS_INCLUDE_MAX32662_MSR_H_ 167
