Use of Array pointers with 8 Unmuxed Analog Inputs

[robinfawell]

Dear Thorsten

Since I first sent this message I realise that I dont need pointers for a character array.  I realise that I only need single quotation marks and dont need the *.  However it should still work. 

Here is the modified code.  I still get the same errors during compilation!

void AIN_NotifyChange(unsigned char pot, unsigned int pin_value) __wparam
{
	//Send Midi Control to Sound Module	 eg B1 08 XX, B0 0B YY etc
    
	unsigned char  status[8] = {'B1', 'B1', 'B1', 'B0', 'B0', 'B0', 'B2', 'B1'};
	unsigned char  byte[8] = {'0x08', '0x0B', '0x09', '0x0B', '0x07', '0x08', '0x0B', '0x01'};




	if( pot >= 0 && pot <=7 ){

	MIOS_MIDI_TxBufferPut(status);
	MIOS_MIDI_TxBufferPut(byte);
	MIOS_MIDI_TxBufferPut(pin_value);}
}

Orig Message I have managed to program on Core 2 the two keyboards complete with:- A)  one Unmuxed  Analog channel generating B1 07 XX B) 2 X 61 keynotes with upper keyboard wired backwards to minimise DIN - DIN cabling C) Coupling of the two keyboards (Double Note On/Off Messages. Thanks very much for your input. 8 Unmuxed Analog Inputs I am attempting to write the code for Core 1 Analog inputs, these are balance controls and Tremelo speed pots.  There are 8 pots.  I have proved that the system will generate Midi Control Changes but  not in the required manner. As you will see below I am attempting to construct a character array pointer with two variables (status) and (byte).  These correspond to the 1st and 2nd bytes of the midi message.  The compilation does not work, I get character incompatibilty problems. (see below).  I am showing the two sections concerned with AIN inputs.

/////////////////////////////////////////////////////////////////////////////
// This function is called by MIOS after startup to initialize the 
// application
/////////////////////////////////////////////////////////////////////////////
void Init(void) __wparam
{
  // initialize the shift registers
  	MIOS_SRIO_NumberSet(16); // shiftregisters
  	MIOS_SRIO_UpdateFrqSet(1); // mS
  
	MIOS_AIN_NumberSet (8); // number of pots
	MIOS_AIN_UnMuxed ;

	//define deadband, use 7
	MIOS_AIN_DeadbandSet (7);

}

/////////////////////////////////////////////////////////////////////////////
// This function is called by MIOS when a pot has been moved
/////////////////////////////////////////////////////////////////////////////
void AIN_NotifyChange(unsigned char pot, unsigned int pin_value) __wparam
{
	//Send Midi Control to Sound Module	 eg B1 08 XX, B0 0B YY etc
    
	unsigned char * status[8] = {"B1", "B1", "B1", "B0", "B0", "B0", "B2", "B1"};
	unsigned char * byte[8] = {"0x08", "0x0B", "0x09", "0x0B", "0x07", "0x08", "0x0B", "0x01"};




	if( pot >= 0 && pot <=7 ){

	MIOS_MIDI_TxBufferPut(status);
	MIOS_MIDI_TxBufferPut(byte);
	MIOS_MIDI_TxBufferPut(pin_value);}
}

[u]Compiler text[/u]

C:\C_Stops>make
Makefile generated.
Makefile.bat generated.
Directory already exists
Assembling MIOS SDCC wrapper
==========================================================================
Compiling pic18f452.c
Processor: 18F452
==========================================================================
Compiling main.c
Processor: 18F452
main.c:238: error 78: incompatible types
from type 'unsigned-char generic*  [8] '
to type 'unsigned-char'
main.c:239: error 78: incompatible types
from type 'unsigned-char generic*  [8] '
to type 'unsigned-char'
-:0: error 103: code not generated for 'AIN_NotifyChange' due to previous errors

ERROR!

Please note that I am trying the' Hex' 0xB1 and 'straight' B1 data.  Both give the same error.

Please help.

Best Regards Robin

[TK.]

Hi Robin,

there are two things, which lead to the error.

One thing is, that you are trying to put illegal characters into the table. Characters are quoted with a ', and just single ASCII bytes, and hex codes - typical usecase for a character: MIOS_LCD_PrintChar('A');

Another thing is, that the array is not accessed correctly. Since you want to select a single element, you have to write status[pot] and byte[pot]

In addition, it isn't a good idea to create a new array with constant definitions each time when AIN_NotifyChange is called. It's better to put such static arrays outside the function, and to declare them as "const"

This leads to the effect, that the compiler will put a table into program flash - in a similar way you know from midio_presets.inc

So, here a code snippet which should work:

/////////////////////////////////////////////////////////////////////////////
// This function is called by MIOS when a pot has been moved
/////////////////////////////////////////////////////////////////////////////
const unsigned char midi_status[8] = {0xB1, 0xB1, 0xB1, 0xB0, 0xB0, 0xB0, 0xB2, 0xB1};
const unsigned char midi_byte[8] = {0x08, 0x0B, 0x09, 0x0B, 0x07, 0x08, 0x0B, 0x01};

void AIN_NotifyChange(unsigned char pin, unsigned int pin_value) __wparam
{
  //Send Midi Control to Sound Module  eg B1 08 XX, B0 0B YY etc
  if( pin >= 0 && pin <=7 ){
    MIOS_MIDI_TxBufferPut(midi_status[pin]);
    MIOS_MIDI_TxBufferPut(midi_byte[pin]);
    MIOS_MIDI_TxBufferPut(pin_value);
  }
}
[/code]
Best Regards, Thorsten.