I am planning to design Multi Channel Audio Mixer + Summing unit which will take audio tracks/signals from different sources/instruments and mix/sum/b...
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I am planning to design Multi Channel Audio Mixer + Summing unit which will take audio tracks/signals from different sources/instruments and mix/sum/block some or all the signals to outputs with PSoC Amux (into 2 Channel mixed audio outputs)
I would appreciate if someone can share some additional electrical characteristics of Amux, what I am looking for is not available on this datasheet
https://www.cypress.com/file/127201/download
It says only this :
DC and AC Electrical Characteristics The AMux operates at all valid supply voltages.
Here are my queries -
1. How much current can Amux paths carry ?
2. Can Amux route isolated signals ? ( signal sharing no common ground with PSoC Chip, kind of like EM relay )
3. What is the trace resistance from input to output through Amux ?
4. Does Amux switching cause audio level noise ?
5. What is the Parasitic Capacitance of Amux circuits ? (to avoid unwanted RC filters)
6. Can Amux carry AC audio signal below PSoC Vss Voltage (Gnd) ?
I have been trying this with two different audio sources (laptop and phone) playing two songs
It somewhat worked with few issues as follows :
1. Signal bleeding/cross-talk from some of the channels
2. Signal Attenuation/Loss of gain
Otherwise, the audio mixing and blocking did worked
Analog pins are set as Strong Drive
Amux is set with Maximum Isolation
Opamp is set for High BW/Power, Medium Cap Compensation
SW is an Input switch for enabling/disabling one or all input audio lines
LED blinks to indicate input combinations
#include <project.h>
int main()
{
AMux_Init();
Pre_Amp_Init();
CyDelay(200);
for(;;)
{
while(SW_Read()){LED_Write(1);}
AMux_DisconnectAll();
while(!SW_Read())
{LED_Write(1); CyDelay(50);LED_Write(0);CyDelay(50);}
if(SW_Read()==0)
{
for(int j=0;j<2;j++)
{
LED_Write(1); CyDelay(200);LED_Write(0);CyDelay(200);
}
AMux_Disconnect(1);AMux_Connect(0);
}
while(SW_Read()){LED_Write(1);}
if(SW_Read()==0)
{
for(int j=0;j<4;j++)
{
LED_Write(1); CyDelay(200);LED_Write(0);CyDelay(200);
}
AMux_Disconnect(0);AMux_Connect(1);
}
while(SW_Read()){LED_Write(1);}
if(SW_Read()==0)
{
for(int j=0;j<6;j++)
{
LED_Write(1); CyDelay(200);LED_Write(0);CyDelay(200);
}
AMux_Connect(0);AMux_Connect(1);
}
while(SW_Read()){LED_Write(1);}
if(SW_Read()==0)
{
for(int j=0;j<10;j++)
{
LED_Write(1); CyDelay(200);LED_Write(0);CyDelay(200);
}
AMux_Connect(2);AMux_Disconnect(1);AMux_Disconnect(3);
}
while(SW_Read()){LED_Write(1);}
if(SW_Read()==0)
{
for(int j=0;j<12;j++)
{
LED_Write(1); CyDelay(200);LED_Write(0);CyDelay(200);
}
AMux_Connect(3);AMux_Disconnect(0);AMux_Disconnect(2);
}
while(SW_Read()){LED_Write(1);}
if(!SW_Read())
{
for(int j=0;j<8;j++)
{
LED_Write(1); CyDelay(200);LED_Write(0);CyDelay(200);
}
AMux_DisconnectAll();
}
while(SW_Read()){LED_Write(1);}
}
}
Message was edited by: ShHo
PSoC Sch added and some of the experimental finding are listed.
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Nov 8, 2019
Solved
