iPod Speaker Dock Idea

I have some speakers I scrapped from a broken LCD TV, and I thought it would be a cool idea to make an iPod dock out of them. I also have a NETduino that i want to implement into this project somehow.

My main problem is the circuitry.

1.) I dont know how to amplify the sound/ what i should use to amplify it

2.) I need to be able to charge the iPod

3.) I want it to get sound from the iPod's dock connector

What i know:

the speakers have 7 ohms of resistance

Any help with this project will be greatly apprecieated

Parents

0 shabaz over 12 years ago

Here is some sample C code to play and skip right/left with the old (pre-lightening) dock connector. I have tested this on the original
iPod touch. It uses the ATmega64, but should be easy to adapt for any processor.
To use it, call ipod_uart_init() at the start of your program, and then use the ipod_tx_cmd() command whenever you wish to
control the iPod, e.g. ipod_tx_cmd(PLAY2) etc..
The '2' is not important, it just means it is a so-called 'type-2' command (the iPod understands some simpler Type-1 commands too, which
I did not implement.

The instructions are in an array which could be extended for other commands if desired.

// Port E
// Ipod Rx/Tx pins: (also used as programming port MOSI/MISO)
#define IPOD_RX 0x01
#define IPOD_TX 0x02

// ***************** COMMANDS *******************
#define PLAY2 0
#define SKIPR2 1
#define SKIPL2 2
#define REL2 3
const unsigned char cmd_arr[]={
/* mode 2 commands */
/* play command */
0x00, 0x00, 0x01,
/* skip right */
0x00, 0x08,
/* skip left */
0x00, 0x10,
/* button release */
0x00, 0x00
};
const unsigned int idx_arr[]={
/* play */
0,
/* skip right */
3,
/* skip left */
5,
/* button release */
7,
/* terminate the array */
9
};
// ipod interface (UART0)
void ipod_uart_init(void)
{
// At 14.7Mhz, UBRR0 set to 47 gives 19200baud
UBRR0H = 0;
UBRR0L = 47;
/* Enable receiver and transmitter */
//UCSR0B = (1<<RXEN0)|(1<<TXEN0);
UCSR0B = (1<<TXEN0);
/* Set frame format: 8data, N, 1stop bit */
UCSR0C = 0x06;
}
// This will transmit a single byte across the ipod interface
void ipod_tx_byte( unsigned char data )
{
/* Wait for empty transmit buffer */
while ( !( UCSR0A & (1<<UDRE0)) )
;
/* Put data into buffer, sends the data */
UDR0 = data;
}
// This will calculate the checksum and transmit all bytes
void ipod_tx_bytes(unsigned char mode, unsigned char* arr, unsigned char length)
{
unsigned int tot;
unsigned char j;
unsigned int check;
unsigned char i;
tot=length+1+mode;
for (j=0; j<length; j++)
{
    tot=tot+arr[j];
}
check=0x100-(tot & 0xff);
ipod_tx_byte(0xff);
ipod_tx_byte(0x55);
ipod_tx_byte(length+1);
ipod_tx_byte(mode);
for (i=0; i< length; i++)
{
    ipod_tx_byte(arr[i]);
}
ipod_tx_byte((unsigned char)check);
}
// This will play a command from the array
void ipod_tx_cmd(unsigned char cmd)
{
int i;
unsigned int index;
unsigned char length;
switch (cmd)
{
    // Mode 2 commands
    case PLAY2:
    case SKIPR2:
    case SKIPL2:
      index=idx_arr[cmd];
      length=(unsigned char) (idx_arr[cmd+1] - idx_arr[cmd]);
      // transmit these commands a few times in case the ipod misses it
      // (will this ever happen?)
      for (i=0; i<3; i++)
      {
        ipod_tx_bytes(2, (unsigned char*)&cmd_arr[index], length);
      }
      // since it was a mode 2 command, now execute 'button release'
      for (i=0; i<3; i++)
      {
        ipod_tx_bytes(2, (unsigned char*)&cmd_arr[idx_arr[REL2]], idx_arr[REL2 + 1] - idx_arr[REL2] );
      }
      break;
default:
      break;
}
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0 shabaz over 12 years ago

Here is some sample C code to play and skip right/left with the old (pre-lightening) dock connector. I have tested this on the original
iPod touch. It uses the ATmega64, but should be easy to adapt for any processor.
To use it, call ipod_uart_init() at the start of your program, and then use the ipod_tx_cmd() command whenever you wish to
control the iPod, e.g. ipod_tx_cmd(PLAY2) etc..
The '2' is not important, it just means it is a so-called 'type-2' command (the iPod understands some simpler Type-1 commands too, which
I did not implement.

The instructions are in an array which could be extended for other commands if desired.

// Port E
// Ipod Rx/Tx pins: (also used as programming port MOSI/MISO)
#define IPOD_RX 0x01
#define IPOD_TX 0x02

// ***************** COMMANDS *******************
#define PLAY2 0
#define SKIPR2 1
#define SKIPL2 2
#define REL2 3
const unsigned char cmd_arr[]={
/* mode 2 commands */
/* play command */
0x00, 0x00, 0x01,
/* skip right */
0x00, 0x08,
/* skip left */
0x00, 0x10,
/* button release */
0x00, 0x00
};
const unsigned int idx_arr[]={
/* play */
0,
/* skip right */
3,
/* skip left */
5,
/* button release */
7,
/* terminate the array */
9
};
// ipod interface (UART0)
void ipod_uart_init(void)
{
// At 14.7Mhz, UBRR0 set to 47 gives 19200baud
UBRR0H = 0;
UBRR0L = 47;
/* Enable receiver and transmitter */
//UCSR0B = (1<<RXEN0)|(1<<TXEN0);
UCSR0B = (1<<TXEN0);
/* Set frame format: 8data, N, 1stop bit */
UCSR0C = 0x06;
}
// This will transmit a single byte across the ipod interface
void ipod_tx_byte( unsigned char data )
{
/* Wait for empty transmit buffer */
while ( !( UCSR0A & (1<<UDRE0)) )
;
/* Put data into buffer, sends the data */
UDR0 = data;
}
// This will calculate the checksum and transmit all bytes
void ipod_tx_bytes(unsigned char mode, unsigned char* arr, unsigned char length)
{
unsigned int tot;
unsigned char j;
unsigned int check;
unsigned char i;
tot=length+1+mode;
for (j=0; j<length; j++)
{
    tot=tot+arr[j];
}
check=0x100-(tot & 0xff);
ipod_tx_byte(0xff);
ipod_tx_byte(0x55);
ipod_tx_byte(length+1);
ipod_tx_byte(mode);
for (i=0; i< length; i++)
{
    ipod_tx_byte(arr[i]);
}
ipod_tx_byte((unsigned char)check);
}
// This will play a command from the array
void ipod_tx_cmd(unsigned char cmd)
{
int i;
unsigned int index;
unsigned char length;
switch (cmd)
{
    // Mode 2 commands
    case PLAY2:
    case SKIPR2:
    case SKIPL2:
      index=idx_arr[cmd];
      length=(unsigned char) (idx_arr[cmd+1] - idx_arr[cmd]);
      // transmit these commands a few times in case the ipod misses it
      // (will this ever happen?)
      for (i=0; i<3; i++)
      {
        ipod_tx_bytes(2, (unsigned char*)&cmd_arr[index], length);
      }
      // since it was a mode 2 command, now execute 'button release'
      for (i=0; i<3; i++)
      {
        ipod_tx_bytes(2, (unsigned char*)&cmd_arr[idx_arr[REL2]], idx_arr[REL2 + 1] - idx_arr[REL2] );
      }
      break;
default:
      break;
}
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