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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 360 | f9daq | 1 | /** |
| 2 | * $Id: calib.c 881 2013-12-16 05:37:34Z rp_jmenart $ |
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| 3 | * |
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| 4 | * @brief Red Pitaya Oscilloscope Calibration Module. |
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| 5 | * |
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| 6 | * @Author Jure Menart <juremenart@gmail.com> |
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| 7 | * |
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| 8 | * (c) Red Pitaya http://www.redpitaya.com |
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| 9 | * |
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| 10 | * This part of code is written in C programming language. |
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| 11 | * Please visit http://en.wikipedia.org/wiki/C_(programming_language) |
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| 12 | * for more details on the language used herein. |
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| 13 | */ |
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| 14 | |||
| 15 | #include <stdio.h> |
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| 16 | #include <stdlib.h> |
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| 17 | #include <errno.h> |
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| 18 | #include <string.h> |
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| 19 | |||
| 20 | #include "calib.h" |
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| 21 | |||
| 22 | const char eeprom_device[]="/sys/bus/i2c/devices/0-0050/eeprom"; |
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| 23 | const int eeprom_calib_off=0x0008; |
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| 24 | |||
| 25 | |||
| 26 | /*----------------------------------------------------------------------------*/ |
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| 27 | /** |
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| 28 | * @brief Read calibration parameters from EEPROM device. |
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| 29 | * |
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| 30 | * Function reads calibration parameters from EEPROM device and stores them to the |
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| 31 | * specified buffer. Communication to the EEPROM device is taken place through |
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| 32 | * appropriate system driver accessed through the file system device |
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| 33 | * /sys/bus/i2c/devices/0-0050/eeprom. |
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| 34 | * |
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| 35 | * @param[out] calib_params Pointer to destination buffer. |
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| 36 | * @retval 0 Success |
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| 37 | * @retval -1 Failure, error message is put on stderr device |
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| 38 | * |
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| 39 | */ |
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| 40 | int rp_read_calib_params(rp_calib_params_t *calib_params) |
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| 41 | { |
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| 42 | FILE *fp; |
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| 43 | size_t size; |
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| 44 | |||
| 45 | /* sanity check */ |
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| 46 | if(calib_params == NULL) { |
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| 47 | fprintf(stderr, "rp_read_calib_params(): input structure " |
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| 48 | "not initialized\n"); |
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| 49 | return -1; |
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| 50 | } |
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| 51 | |||
| 52 | /* open eeprom device */ |
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| 53 | fp=fopen(eeprom_device, "r"); |
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| 54 | if(fp == NULL) { |
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| 55 | fprintf(stderr, "rp_read_calib_params(): Can not open EEPROM device: " |
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| 56 | " %s\n", strerror(errno)); |
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| 57 | return -1; |
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| 58 | } |
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| 59 | |||
| 60 | /* ...and seek to the appropriate storage offset */ |
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| 61 | if(fseek(fp, eeprom_calib_off, SEEK_SET) < 0) { |
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| 62 | fclose(fp); |
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| 63 | fprintf(stderr, "rp_read_calib_params(): fseek() failed: %s\n", |
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| 64 | strerror(errno)); |
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| 65 | return -1; |
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| 66 | } |
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| 67 | |||
| 68 | /* read data from eeprom component and store it to the specified buffer */ |
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| 69 | size=fread(calib_params, sizeof(char), sizeof(rp_calib_params_t), fp); |
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| 70 | if(size != sizeof(rp_calib_params_t)) { |
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| 71 | fclose(fp); |
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| 72 | fprintf(stderr, "rp_read_calib_params(): fread() failed, " |
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| 73 | "returned bytes: %d (should be :%d)\n", size, |
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| 74 | sizeof(rp_calib_params_t)); |
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| 75 | return -1; |
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| 76 | } |
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| 77 | fclose(fp); |
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| 78 | |||
| 79 | return 0; |
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| 80 | } |
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| 81 | |||
| 82 | |||
| 83 | /*----------------------------------------------------------------------------*/ |
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| 84 | /** |
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| 85 | * Initialize calibration parameters to default values. |
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| 86 | * |
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| 87 | * @param[out] calib_params Pointer to target buffer to be initialized. |
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| 88 | * @retval 0 Success, could never fail. |
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| 89 | */ |
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| 90 | |||
| 91 | int rp_default_calib_params(rp_calib_params_t *calib_params) |
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| 92 | { |
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| 93 | calib_params->fe_ch1_fs_g_hi = 28101971; /* 0.6543 [V] */ |
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| 94 | calib_params->fe_ch2_fs_g_hi = 28101971; /* 0.6543 [V] */ |
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| 95 | calib_params->fe_ch1_fs_g_lo = 625682246; /* 14.56 [V] */ |
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| 96 | calib_params->fe_ch2_fs_g_lo = 625682246; /* 14.56 [V] */ |
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| 97 | calib_params->fe_ch1_dc_offs = 585; |
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| 98 | calib_params->fe_ch2_dc_offs = 585; |
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| 99 | calib_params->be_ch1_fs = 42949673; /* 1 [V] */ |
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| 100 | calib_params->be_ch2_fs = 42949673; /* 1 [V] */ |
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| 101 | calib_params->be_ch1_dc_offs = 0x3eac; |
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| 102 | calib_params->be_ch2_dc_offs = 0x3eac; |
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| 103 | |||
| 104 | return 0; |
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| 105 | } |