Masahiro Furukawa / Mbed 2 deprecated MPU-9250-MagSens_M-Series

2Chx3dof Magnetrometer supported M-Series Random Sequence Generator Servo Control

Dependencies:   mbed

Sampling Frequency

Sampling Frequency in main.cpp

#define SampleFreq     200   // [Hz]

Auto Stop Setting

Auto-stop Timer 15sec after

    // auto-stop when 15sec after
    if(smpl_cnt>3000){stop_dump();}

The number of 3000 means Sample Count. The number is given by SampleFreq[Hz] * Auto-Stop Time [sec].

M-Series Random Sequence

M-series Random Update Term in main.cpp

// M-series update flag
#define  M_TERM  200;

Unit is sample count.

cf.) 200 equals to 200 [samples] which equals to 1 [second] where SampleFreq = 200 [Hz}.

See above.

M-Series Random Servo Control

M-Series.h

Committer:
mfurukawa
Date:
2021-02-02
Branch:
MPU-9250-MagSensServo
Revision:
9:b32312aacbba
Parent:
8:07c3cb01a5b6

File content as of revision 9:b32312aacbba:

//
// M-Series Random Sequence Generator
//
// Masahiro Furukawa, m.furukawa@ist.osaka-u.ac.jp
// Feb 2, 2021

// m-sequence
// https://okasho-engineer.com/m-sequence/
//
// Maximum-Length Tap Position and Number of taps
// http://wista.jp/M-Seq.htm
//
// 既約多項式
// https://www.nagoya-bunri.ac.jp//~t-ymzm/rand/rand_mseq4.html

#ifndef __M_SERIES_H__
#define __M_SERIES_H__

#define   MSeries_N   16

// m-series definition
class Mseries
{
private:
    uint8_t M[MSeries_N];
    uint8_t H[MSeries_N];

public:
    Mseries()
    {
        init();
    }

    void init(void)
    {
        // the following initial values are not validated
        M[0] = 0;
        M[1] = 0;
        M[2] = 0;
        M[3] = 1;
        M[4] = 0;
        M[5] = 0;
        M[6] = 0;
        M[7] = 1;
        M[8] = 0;
        M[9] = 0;
        M[10] = 0;
        M[11] = 1;
        M[12] = 0;
        M[13] = 0;
        M[14] = 0;
        M[15] = 1;

        // Maximum-Length Tap Position and Number of taps
        // http://www5b.biglobe.ne.jp/~pisan/radio-Msequence.htm
        //
        H[0] = 1;
        H[1] = 0;
        H[2] = 1;
        H[3] = 0;

        H[4] = 0;
        H[5] = 0;
        H[6] = 0;
        H[7] = 0;

        H[8]  = 0;
        H[9]  = 0;
        H[10] = 0;
        H[11] = 1;

        H[12] = 0;
        H[13] = 0;
        H[14] = 0;
        H[15] = 1;

    }

    uint8_t update(void)
    {
        // update M-series
        uint8_t Mtmp = M[0] * H[0];

        // one left-shifting on ring buffer
        M[0] = M[1];

        // take sequential XOR on the entire sequence
        for (int i = 1 ; i < MSeries_N - 1 ; i++) {
            // XOR
            Mtmp = (Mtmp + M[i] * H[i]) % 2;

            // one left-shifting on ring buffer
            M[i] = M[i + 1];
        }

        // store the latest value at the last
        M[MSeries_N - 1] = Mtmp;

        return get();
    }

    uint8_t get(void)
    {
        return M[15];
    }
};


#endif // __M_SERIES_H__