diff options
Diffstat (limited to 'libsensors_iio/software/core/mllite/ml_math_func.c')
-rw-r--r-- | libsensors_iio/software/core/mllite/ml_math_func.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/libsensors_iio/software/core/mllite/ml_math_func.c b/libsensors_iio/software/core/mllite/ml_math_func.c index 86c4b41..cce0381 100644 --- a/libsensors_iio/software/core/mllite/ml_math_func.c +++ b/libsensors_iio/software/core/mllite/ml_math_func.c @@ -655,6 +655,52 @@ double inv_vector_norm(const float *x) { return sqrt(x[0]*x[0]+x[1]*x[1]+x[2]*x[2]); } + +void inv_init_biquad_filter(inv_biquad_filter_t *pFilter, float *pBiquadCoeff) { + int i; + // initial state to zero + pFilter->state[0] = 0; + pFilter->state[1] = 0; + + // set up coefficients + for (i=0; i<5; i++) { + pFilter->c[i] = pBiquadCoeff[i]; + } +} + +void inv_calc_state_to_match_output(inv_biquad_filter_t *pFilter, float input) +{ + pFilter->input = input; + pFilter->output = input; + pFilter->state[0] = input / (1 + pFilter->c[2] + pFilter->c[3]); + pFilter->state[1] = pFilter->state[0]; +} + +float inv_biquad_filter_process(inv_biquad_filter_t *pFilter, float input) { + float stateZero; + + pFilter->input = input; + // calculate the new state; + stateZero = pFilter->input - pFilter->c[2]*pFilter->state[0] + - pFilter->c[3]*pFilter->state[1]; + + pFilter->output = stateZero + pFilter->c[0]*pFilter->state[0] + + pFilter->c[1]*pFilter->state[1]; + + // update the output and state + pFilter->output = pFilter->output * pFilter->c[4]; + pFilter->state[1] = pFilter->state[0]; + pFilter->state[0] = stateZero; + return pFilter->output; +} + +void inv_get_cross_product_vec(float *cgcross, float compass[3], float grav[3]) { + + cgcross[0] = (float)compass[1] * grav[2] - (float)compass[2] * grav[1]; + cgcross[1] = (float)compass[2] * grav[0] - (float)compass[0] * grav[2]; + cgcross[2] = (float)compass[0] * grav[1] - (float)compass[1] * grav[0]; +} + /** * @} */ |