stefanodi
Member
Hi, I made a receiver for HF bands with Teensy 4.0 and https://github.com/chipaudette/OpenAudio_ArduinoLibrary
For SSB & FM reception no problem, I have to solve the amplitude modulated reception.
I thought of using and modifying the code that worked very well in the already built receiver.
This is the old original code (unmodified):
I'm not a programming expert, I tried modifying the previous code like this:
I'm not getting compile errors, but it doesn't work.
I kindly ask if I can get some help.
Thank you.
Stefano
For SSB & FM reception no problem, I have to solve the amplitude modulated reception.
I thought of using and modifying the code that worked very well in the already built receiver.
This is the old original code (unmodified):
Code:
Code file: AMDemod.h
/* Audio Library for Teensy 3.X
* Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
*
* Development of this audio library was funded by PJRC.COM, LLC by sales of
* Teensy and Audio Adaptor boards. Please support PJRC's efforts to develop
* open source software by purchasing Teensy or other PJRC products.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice, development funding notice, and this permission
* notice shall be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "Arduino.h"
#include "AudioStream.h"
#include "arm_math.h"
class AMDemod : public AudioStream
{
public:
AMDemod() : AudioStream(2, inputQueueArray),pass(1){ }
void passthrough(bool p) {
pass = p;
}
virtual void update(void);
private:
audio_block_t *inputQueueArray[2];
bool pass;
};
///////////////////////////////////////////////////////////////////////////////////////////////
Code file: AMDemod.cpp
/* Audio Library for Teensy 3.X
* Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
*
* Development of this audio library was funded by PJRC.COM, LLC by sales of
* Teensy and Audio Adaptor boards. Please support PJRC's efforts to develop
* open source software by purchasing Teensy or other PJRC products.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice, development funding notice, and this permission
* notice shall be included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "AM_demod.h"
#include "utility/dspinst.h"
void AMDemod::update(void)
{
if (!pass) return;
audio_block_t *blocki, *blockq;
int16_t *pi, *pq, *end;
int32_t sum;
blocki = receiveWritable(0); // receives I, end result is written in channel 0
blockq = receiveReadOnly(1); // receives Q
if (!blocki) {
if (blockq) release(blockq);
return;
}
if (!blockq) {
release(blocki);
return;
}
pi = (int16_t *)(blocki->data);
pq = (int16_t *)(blockq->data);
end = pi + AUDIO_BLOCK_SAMPLES;
while (pi < end) {
// square and sum I and Q
sum = *pi * *pi;
sum += *pq * *pq;
// The result of squaring a 1.15 is 2.30.
// Shift the sum up one bit to make it 1.31 (Q31)
// and then that becomes the input to the arm sqrt function
sum <<= 1;
arm_sqrt_q31((q31_t)sum,(q31_t *) &sum);
// The result is in the high order 16 bits of sum
*pi++ = sum >> 16;
pq++;
}
transmit(blocki);
release(blocki);
release(blockq);
}
I'm not a programming expert, I tried modifying the previous code like this:
Code:
Code file: AMDemod.h
#include "AudioStream_F32.h"
#include "arm_math.h"
class AMDemod : public AudioStream_F32{
public:
AMDemod() : AudioStream_F32(2, inputQueueArray_f32),pass(1) { }
// AMDemod(const AudioSettings_F32 &settings) : AudioStream_F32(2, inputQueueArray_f32) { }
void passthrough(bool p) {pass = p;}
virtual void update(void);
private:
audio_block_f32_t *inputQueueArray_f32[2];
bool pass;
};
#endif
//////////////////////////////////////////////////////////////////////////////////////
Code file: AMDemod.cpp
#include "AM_demod.h"
void AMDemod::update(void){
if (!pass) return;
audio_block_f32_t *blocki, *blockq;
int16_t *pi, *pq, *end;
int32_t sum;
blocki = receiveWritable_f32(0); // receives I, end result is written in channel 0
blockq = receiveReadOnly_f32(1); // receives Q
if (!blocki) {if (blockq) release(blockq);return;}
if (!blockq) {release(blocki);return;}
pi = (int16_t *)(blocki->data);
pq = (int16_t *)(blockq->data);
end = pi + AUDIO_BLOCK_SAMPLES;
while (pi < end) {
// square and sum I and Q
sum = *pi * *pi;
sum += *pq * *pq;
// The result of squaring a 1.15 is 2.30.
// Shift the sum up one bit to make it 1.31 (Q31)
// and then that becomes the input to the arm sqrt function
sum <<= 1;
arm_sqrt_q31((q31_t)sum,(q31_t *) &sum);
// The result is in the high order 16 bits of sum
*pi++ = sum >> 16;
pq++;
}
transmit(blocki);
release(blocki);
release(blockq);
}
I kindly ask if I can get some help.
Thank you.
Stefano