Audio bridge to Ethernet, is it possible?

[tschrama]

Hi all,

Your options are welcome on this idea:
Would it be possible to make a Audio to ethernet bridge on a teensy 4.1?

Audio will be send from an external ADC using TDM, 100kHz, 24 bits, 4 or 8 channels. This audio needs to be processed on a Rasb Pi. I figured a Ethernet connection might be good for that task.

Is it possible, or should I look for different route?


Thanks for any comments you might have.
Thijs Schrama

[tschrama]

Just Bumping.... I am about to start working on this task. Any warning, remarks, opinions are welcome.

[tschrama]

Today I started experimenting.

This code compiles fine, but halts the ethernet configuration. Do any of you know why?

/ MATLABUDPBroadcastExample.ino
// Copyright 2016 The MathWorks, Inc.
// some edits T Schrama july 2020 for teensy 4.1 nativeEthernet

#include <SPI.h>
#include <Ethernet.h>
#include <EthernetUdp.h>

int ledPin = LED_BUILTIN;                                    // Connect an LED->330Ohm to pin 5 or LED_BUILTIN

int packetSize;

//byte mac[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xAD, 0xDE};

uint8_t mac[6];

unsigned int broadcastPort = 31416;      
char packetBuffer[UDP_TX_PACKET_MAX_SIZE];  
char  ArduinoAckMessage[] = "Arduino:ACK\r";       // "\r" is the carriage return, i.e., char(13)
char MATLABBlinkItCommand[] = "MATLAB:BlinkIt\r";  
EthernetUDP Udp;
IPAddress broadcastAddress;

void setup()
{
  teensyMAC(mac);  // function to auire Teensy 4.1 NativeEthernet MAC,  function is define below
  Serial.begin(9600);
  if (Ethernet.begin(mac)==0){
    Serial.println("Failed to configure Ethernet. Halt.");
    delay(1000);                                  // Allow some time for message to be printed
    abort();
  }
  Serial.print("Arduino's IP Address is: ");
  Serial.println(Ethernet.localIP());
  Udp.begin(broadcastPort);  
  pinMode(ledPin, OUTPUT);      
  digitalWrite(ledPin, LOW);    
}

void loop()
{
  // if there's data available, read a packet
  packetSize = Udp.parsePacket();
  if (packetSize) {
    Serial.print("Message: ");
    Udp.read(packetBuffer, UDP_TX_PACKET_MAX_SIZE);
    packetBuffer[packetSize] = '\0';
    Serial.println(packetBuffer);
    if (strcmp(packetBuffer, MATLABBlinkItCommand) == 0)
    {
      broadcastAddress = Udp.remoteIP();
      broadcastAddress[3] = 255;
      Udp.beginPacket(broadcastAddress, broadcastPort);
      Udp.write(ArduinoAckMessage);
      Udp.endPacket();
      digitalWrite(ledPin, HIGH);                   // sets the LED on
      delay(1000);                                  // waits for a second
      digitalWrite(ledPin, LOW);                    // sets the LED off
    }
  }
  delay(10);  
}

// code to aquire MAC adres of teensy 4.1 nativeEthernet
void teensyMAC(uint8_t *mac) {

  static char teensyMac[23];
  
  #if defined(HW_OCOTP_MAC1) && defined(HW_OCOTP_MAC0)
    Serial.println("using HW_OCOTP_MAC* - see https://forum.pjrc.com/threads/57595-Serial-amp-MAC-Address-Teensy-4-0");
    for(uint8_t by=0; by<2; by++) mac[by]=(HW_OCOTP_MAC1 >> ((1-by)*8)) & 0xFF;
    for(uint8_t by=0; by<4; by++) mac[by+2]=(HW_OCOTP_MAC0 >> ((3-by)*8)) & 0xFF;

    #define MAC_OK

  #else
    
    mac[0] = 0x04;
    mac[1] = 0xE9;
    mac[2] = 0xE5;

    uint32_t SN=0;
    __disable_irq();
    
    #if defined(HAS_KINETIS_FLASH_FTFA) || defined(HAS_KINETIS_FLASH_FTFL)
      Serial.println("using FTFL_FSTAT_FTFA - vis teensyID.h - see https://github.com/sstaub/TeensyID/blob/master/TeensyID.h");
      
      FTFL_FSTAT = FTFL_FSTAT_RDCOLERR | FTFL_FSTAT_ACCERR | FTFL_FSTAT_FPVIOL;
      FTFL_FCCOB0 = 0x41;
      FTFL_FCCOB1 = 15;
      FTFL_FSTAT = FTFL_FSTAT_CCIF;
      while (!(FTFL_FSTAT & FTFL_FSTAT_CCIF)) ; // wait
      SN = *(uint32_t *)&FTFL_FCCOB7;

      #define MAC_OK
      
    #elif defined(HAS_KINETIS_FLASH_FTFE)
      Serial.println("using FTFL_FSTAT_FTFE - vis teensyID.h - see https://github.com/sstaub/TeensyID/blob/master/TeensyID.h");
      
      kinetis_hsrun_disable();
      FTFL_FSTAT = FTFL_FSTAT_RDCOLERR | FTFL_FSTAT_ACCERR | FTFL_FSTAT_FPVIOL;
      *(uint32_t *)&FTFL_FCCOB3 = 0x41070000;
      FTFL_FSTAT = FTFL_FSTAT_CCIF;
      while (!(FTFL_FSTAT & FTFL_FSTAT_CCIF)) ; // wait
      SN = *(uint32_t *)&FTFL_FCCOBB;
      kinetis_hsrun_enable();

      #define MAC_OK
      
    #endif
    
    __enable_irq();

    for(uint8_t by=0; by<3; by++) mac[by+3]=(SN >> ((2-by)*8)) & 0xFF;

  #endif

  #ifdef MAC_OK
    sprintf(teensyMac, "MAC: %02x:%02x:%02x:%02x:%02x:%02x", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
    Serial.println(teensyMac);
  #else
    Serial.println("ERROR: could not get MAC");
  #endif
}

[tschrama]

OK, got it working.

First, I had to bridge my ethernet in my computer, so the teensy sees my DHCP from my home-internet-provider-modem(?)
Second, I had to change the ethernet library to the nativeEthrnet library.

#include <fnet.h>
#include <fnet_config.h>
#include <fnet_user_config.h>

#include <NativeEthernet.h>

// MATLABUDPBroadcastExample.ino
// Copyright 2016 The MathWorks, Inc.
// some edits T Schrama july 2020 for teensy 4.1 nativeEthernet

#include <SPI.h>
//#include <Ethernet.h>
//#include <EthernetUdp.h>

int ledPin = LED_BUILTIN;                                    // Connect an LED->330Ohm to pin 5 or LED_BUILTIN

int packetSize;

//byte mac[] = {0xDE, 0xAD, 0xBE, 0xEF, 0xAD, 0xDE};

uint8_t mac[6];

unsigned int broadcastPort = 31416;      
char packetBuffer[UDP_TX_PACKET_MAX_SIZE];  
char  ArduinoAckMessage[] = "Arduino:ACK\r";       // "\r" is the carriage return, i.e., char(13)
char MATLABBlinkItCommand[] = "MATLAB:BlinkIt\r";  
EthernetUDP Udp;
IPAddress broadcastAddress;

void setup()
{
  teensyMAC(mac);                                // function to auqire Teensy 4.1 NativeEthernet MAC,  function is defined below
  Serial.begin(9600);
  if (Ethernet.begin(mac)==0){
    Serial.println("Failed to configure Ethernet. Halt.");
    delay(1000);                                  // Allow some time for message to be printed
    abort();
  }
  Serial.print("Arduino's IP Address is: ");
  Serial.println(Ethernet.localIP());
  Udp.begin(broadcastPort);  
  pinMode(ledPin, OUTPUT);      
  digitalWrite(ledPin, LOW);    
}

void loop()
{
  // if there's data available, read a packet
  packetSize = Udp.parsePacket();
  if (packetSize) {
    Serial.print("Message: ");
    Udp.read(packetBuffer, UDP_TX_PACKET_MAX_SIZE);
    packetBuffer[packetSize] = '\0';
    Serial.println(packetBuffer);
    if (strcmp(packetBuffer, MATLABBlinkItCommand) == 0)
    {
      broadcastAddress = Udp.remoteIP();
      broadcastAddress[3] = 255;
      Udp.beginPacket(broadcastAddress, broadcastPort);
      Udp.write(ArduinoAckMessage);
      Udp.endPacket();
      digitalWrite(ledPin, HIGH);                   // sets the LED on
      delay(1000);                                  // waits for a second
      digitalWrite(ledPin, LOW);                    // sets the LED off
    }
  }
  delay(10);  
}

// code to aquire MAC adres of teensy 4.1 nativeEthernet
void teensyMAC(uint8_t *mac) {

  static char teensyMac[23];
  
  #if defined(HW_OCOTP_MAC1) && defined(HW_OCOTP_MAC0)
    Serial.println("using HW_OCOTP_MAC* - see https://forum.pjrc.com/threads/57595-Serial-amp-MAC-Address-Teensy-4-0");
    for(uint8_t by=0; by<2; by++) mac[by]=(HW_OCOTP_MAC1 >> ((1-by)*8)) & 0xFF;
    for(uint8_t by=0; by<4; by++) mac[by+2]=(HW_OCOTP_MAC0 >> ((3-by)*8)) & 0xFF;

    #define MAC_OK

  #else
    
    mac[0] = 0x04;
    mac[1] = 0xE9;
    mac[2] = 0xE5;

    uint32_t SN=0;
    __disable_irq();
    
    #if defined(HAS_KINETIS_FLASH_FTFA) || defined(HAS_KINETIS_FLASH_FTFL)
      Serial.println("using FTFL_FSTAT_FTFA - vis teensyID.h - see https://github.com/sstaub/TeensyID/blob/master/TeensyID.h");
      
      FTFL_FSTAT = FTFL_FSTAT_RDCOLERR | FTFL_FSTAT_ACCERR | FTFL_FSTAT_FPVIOL;
      FTFL_FCCOB0 = 0x41;
      FTFL_FCCOB1 = 15;
      FTFL_FSTAT = FTFL_FSTAT_CCIF;
      while (!(FTFL_FSTAT & FTFL_FSTAT_CCIF)) ; // wait
      SN = *(uint32_t *)&FTFL_FCCOB7;

      #define MAC_OK
      
    #elif defined(HAS_KINETIS_FLASH_FTFE)
      Serial.println("using FTFL_FSTAT_FTFE - vis teensyID.h - see https://github.com/sstaub/TeensyID/blob/master/TeensyID.h");
      
      kinetis_hsrun_disable();
      FTFL_FSTAT = FTFL_FSTAT_RDCOLERR | FTFL_FSTAT_ACCERR | FTFL_FSTAT_FPVIOL;
      *(uint32_t *)&FTFL_FCCOB3 = 0x41070000;
      FTFL_FSTAT = FTFL_FSTAT_CCIF;
      while (!(FTFL_FSTAT & FTFL_FSTAT_CCIF)) ; // wait
      SN = *(uint32_t *)&FTFL_FCCOBB;
      kinetis_hsrun_enable();

      #define MAC_OK
      
    #endif
    
    __enable_irq();

    for(uint8_t by=0; by<3; by++) mac[by+3]=(SN >> ((2-by)*8)) & 0xFF;

  #endif

  #ifdef MAC_OK
    sprintf(teensyMac, "MAC: %02x:%02x:%02x:%02x:%02x:%02x", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
    Serial.println(teensyMac);
  #else
    Serial.println("ERROR: could not get MAC");
  #endif
}