82 lines
2.9 KiB
C
82 lines
2.9 KiB
C
/* -*- mode: c; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4; coding: utf-8 -*- */
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/************************************************************************************
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** **
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** mcHF QRP Transceiver **
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** K Atanassov - M0NKA 2014 **
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** **
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**---------------------------------------------------------------------------------**
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** **
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** File name: **
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** Description: **
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** Last Modified: **
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** Licence: GNU GPLv3 **
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************************************************************************************/
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#ifndef __SOFTDDS_H
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#define __SOFTDDS_H
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#include "dds_table.h"
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// we use a 32 bit accumulator
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#define SOFTDDS_ACC_SHIFT (32-DDS_TBL_BITS)
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// Soft DDS public structure
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typedef struct
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{
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// DDS accumulator
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uint32_t acc;
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// DDS step - not working if part of the structure
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uint32_t step;
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} soft_dds_t;
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/**
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* Execute a single step in the sinus generation
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*/
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inline uint32_t softdds_nextSampleIndex(soft_dds_t* dds)
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{
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uint32_t retval = (dds->acc >> SOFTDDS_ACC_SHIFT)%DDS_TBL_SIZE;
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dds->acc += dds->step;
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// now scale down precision and make sure that
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// index wraps around properly
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return retval;
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}
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/*
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* Get the index which represents a -90 degree shift compared to
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* k, i.e. get k = sin(a) => cos(a)
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*/
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inline uint32_t softdds_phase_shift90(uint32_t k)
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{
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// make sure that
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// index wraps around properly
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return (k+(3*DDS_TBL_SIZE/4))%DDS_TBL_SIZE;
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}
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/**
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* Execute a single step in the sinus generation and return actual sample value
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*/
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inline int16_t softdds_nextSample(soft_dds_t* dds)
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{
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return DDS_TABLE[softdds_nextSampleIndex(dds)];
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}
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void softdds_setFreqDDS(soft_dds_t* dds, float32_t freq, uint32_t samp_rate, uint8_t smooth);
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void softdds_genIQSingleTone(soft_dds_t* dds, float32_t *i_buff,float32_t *q_buff,uint16_t size);
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void softdds_genIQTwoTone(soft_dds_t* ddsA, soft_dds_t* ddsB, float *i_buff,float *q_buff,ushort size);
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void softdds_addSingleTone(soft_dds_t* dds_ptr, float32_t* buffer, const size_t blockSize, float32_t scaling);
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void softdds_addSingleToneToTwobuffers(soft_dds_t* dds_ptr, float32_t* buffer1, float32_t* buffer2, const size_t blockSize, float32_t scaling);
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void softdds_runIQ(float32_t *i_buff, float32_t *q_buff, uint16_t size);
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void softdds_configRunIQ(float32_t freq[2],uint32_t samp_rate,uint8_t smooth);
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#endif
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