Discussions about active development projects
#7734 by fbalakirev
Fri Jul 14, 2017 11:57 pm
Hi Nils,

I would like to clarify EEPROM values order. I tested it with Red Pitaya oscilloscope web app and it looks to me that this app interprets is s with 1V range at address 8 (jumper in LV position), followed by 20V range at address 12 (jumper in 20V position)

Another source of confusion is the sign of the offset. If I look at RedPitaya/api/src/common.c at Red Pitaya github:

Code: Select allint32_t cmn_CalibCnts(uint32_t field_len, uint32_t cnts, int calib_dc_off)
{
    /* adopt ADC count with calibrated DC offset */
    m -= calib_dc_off;
}


the EEPROM offset is subtracted. The web app adds EEPROM offset instead.

I would really appreciate some clarification from Red Pitaya team!
#7741 by fbalakirev
Mon Jul 17, 2017 4:49 pm
P.S. Could someone at Red Pitaya also clarify which offset field in rp_calib_params_t corresponds to LV and which one correspond to HV jumper position? It appears to me that fe_ch*_lo_offs is used for HV and fe_ch1_hi_offs is for LV (if magic==0xAABBCCDD) if I follow the naming convention:

Code: Select all/**
 * Calibration parameters, stored in the EEPROM device
 */
typedef struct {
    uint32_t fe_ch1_fs_g_hi; //!< High gain front end full scale voltage, channel A
    uint32_t fe_ch2_fs_g_hi; //!< High gain front end full scale voltage, channel B
    uint32_t fe_ch1_fs_g_lo; //!< Low gain front end full scale voltage, channel A
    uint32_t fe_ch2_fs_g_lo; //!< Low gain front end full scale voltage, channel B
    int32_t  fe_ch1_lo_offs; //!< Front end DC offset, channel A
    int32_t  fe_ch2_lo_offs; //!< Front end DC offset, channel B
    uint32_t be_ch1_fs;      //!< Back end full scale voltage, channel A
    uint32_t be_ch2_fs;      //!< Back end full scale voltage, channel B
    int32_t  be_ch1_dc_offs; //!< Back end DC offset, channel A
    int32_t  be_ch2_dc_offs; //!< Back end DC offset, on channel B
   uint32_t magic;          //!
    int32_t  fe_ch1_hi_offs; //!< Front end DC offset, channel A
    int32_t  fe_ch2_hi_offs; //!< Front end DC offset, channel B
} rp_calib_params_t;

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