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Adding DC estimator filter for all modes

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This commit is contained in:
Andy CA6JAU 2017-07-06 00:51:46 -04:00
parent 6c4496e034
commit f8d767913e
11 changed files with 42 additions and 34 deletions
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28
IO.cpp
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@ -36,6 +36,10 @@ const uint16_t GAUSSIAN_0_5_FILTER_LEN = 12U;
static q15_t BOXCAR_FILTER[] = {3000, 3000, 3000, 3000, 3000, 0};
const uint16_t BOXCAR_FILTER_LEN = 6U;
// Generated using [b, a] = butter(1, 0.001) in MATLAB
static q31_t DC_FILTER[] = {3367972, 0, 3367972, 0, 2140747704, 0}; // {b0, 0, b1, b2, -a1, -a2}
const uint32_t DC_FILTER_STAGES = 1U; // One Biquad stage
const uint16_t DC_OFFSET = 2048U;
CIO::CIO() :
@ -62,11 +66,14 @@ m_detect(false),
m_adcOverflow(0U),
m_dacOverflow(0U),
m_watchdog(0U),
m_lockout(false)
m_lockout(false),
m_dcFilter(),
m_dcState()
{
::memset(m_rrcState, 0x00U, 70U * sizeof(q15_t));
::memset(m_gaussianState, 0x00U, 40U * sizeof(q15_t));
::memset(m_boxcarState, 0x00U, 30U * sizeof(q15_t));
::memset(m_dcState, 0x00U, 4U * sizeof(q31_t));
m_rrcFilter.numTaps = RRC_0_2_FILTER_LEN;
m_rrcFilter.pState = m_rrcState;
@ -79,6 +86,11 @@ m_lockout(false)
m_boxcarFilter.numTaps = BOXCAR_FILTER_LEN;
m_boxcarFilter.pState = m_boxcarState;
m_boxcarFilter.pCoeffs = BOXCAR_FILTER;
m_dcFilter.numStages = DC_FILTER_STAGES;
m_dcFilter.pState = m_dcState;
m_dcFilter.pCoeffs = DC_FILTER;
m_dcFilter.postShift = 0;
initInt();
}
@ -156,6 +168,20 @@ void CIO::process()
if (m_lockout)
return;
q31_t dc_level = 0;
q31_t dcVals[20];
q31_t intSamp[20];
::arm_q15_to_q31((q15_t*)samples, intSamp, RX_BLOCK_SIZE);
::arm_biquad_cascade_df1_q31(&m_dcFilter, intSamp, dcVals, RX_BLOCK_SIZE);
for (uint8_t i = 0U; i < RX_BLOCK_SIZE; i++)
dc_level += dcVals[i];
dc_level /= RX_BLOCK_SIZE;
m_dc_level = (q15_t) (dc_level >> 16);
if (m_modemState == STATE_IDLE) {
if (m_dstarEnable) {