Implemented MIDI interface

8 files changed, 209 insertions, 161 deletions

diff --git a/floppyMusic/floppy.c b/floppyMusic/floppy.c
index 6a12af6..b065302 100644
--- a/floppyMusic/floppy.c
+++ b/floppyMusic/floppy.c
@@ -15,11 +15,11 @@ ISR(TIMER0_OVF_vect)
 
 	*fPORT = 0xff; //Deactivate all previously activated pins
 
-	for(uint8_t i = 0; i < 8; i++)
+	for(uint8_t i = 0; i < 8; i++) //Perform check of every channel
 	{
-		if(floppy_nextrun[i] == timer_overflow_counter && floppy_frequencies[i] > 0)
+		if(floppy_nextrun[i] == timer_overflow_counter && floppy_frequencies[i] > 0) //check if pulse is due
 		{
-			floppy_nextrun[i] += floppy_frequencies[i];
+			floppy_nextrun[i] += floppy_frequencies[i]; //set next pulse
 			floppy_pulse(i);
 		}
 	}
@@ -27,7 +27,7 @@ ISR(TIMER0_OVF_vect)
 	sei();
 }
 
-void floppy_setup(char *_pulse_port, char *_pulse_ddr, char *_direction_port, char *_direction_ddr)
+void floppy_setup(unsigned char *_pulse_port, unsigned char *_pulse_ddr, unsigned char *_direction_port, unsigned char *_direction_ddr)
  {
 	//Setup Ports
 	fPORT	= _pulse_port;
@@ -89,6 +89,8 @@ void floppy_setup(char *_pulse_port, char *_pulse_ddr, char *_direction_port, ch
 
  uint8_t floppy_calc_freq(uint32_t _f_hz)
  {
+
+	///TODO Shift notes out of effective range of FDD into range
 	if(_f_hz < 31)
 		return 255;
 	if(_f_hz > 7813)
diff --git a/floppyMusic/floppy.h b/floppyMusic/floppy.h
index cc069c0..b0a45cb 100644
--- a/floppyMusic/floppy.h
+++ b/floppyMusic/floppy.h
@@ -10,7 +10,7 @@
 #define FLOPPY_H_
 
 #ifndef F_CPU
-#define F_CPU 16000000UL
+#error F_CPU not defined for floppy.h
 #endif
 
 #include <avr/io.h>
@@ -22,15 +22,32 @@ uint8_t floppy_frequencies[8];
 uint8_t floppy_nextrun[8];
 uint8_t floppy_head_return_counter[8];
 
-char *fPORT, *fDDR, *dPORT, *dDDR; //Ports for floppy and Direction of Heads
-
-void floppy_setup(char *_pulse_port, char *_pulse_ddr, char *_direction_port, char *_direction_ddr);
+unsigned char *fPORT, *fDDR, *dPORT, *dDDR; //Ports for floppy and Direction of Heads
 
+void floppy_setup(unsigned char *_pulse_port, unsigned char *_pulse_ddr, unsigned char *_direction_port, unsigned char *_direction_ddr);
+/*
+* *_pulse_port : port where stepper is connected, eg &PORTA
+* *_pulse_ddr  : its direction register, eg &DDRA
+* *_direction_port : Port where direction pins are connected, eg &PORTB
+* *_direction_ddr  : its direction register, eg &DDRB
+*/
 void floppy_set_frequency(uint8_t _floppy_id, uint8_t _freq);
+/*
+* _floppy_id : [0-7] channel select
+* _freq : [0-255] numerical value representing frequency. use floppy_calc_freq() to calculate from frequency in Hz
+*/
 
 void floppy_pulse(uint8_t _floppy_id);
+/*
+* pulses FDD, keeps track of when to apply head-reverse signal
+* _floppy_id : [0-7] channel select
+*/
 
 uint8_t floppy_calc_freq(uint32_t _f_hz);
+/*
+* Converts frequency in Hz into value used by floppy_set_frequency()
+* _f_hz : Frequency in Hz
+*/
 
 
 #endif /* FLOPPY_H_ */
\ No newline at end of file
diff --git a/floppyMusic/floppyMusic.cproj b/floppyMusic/floppyMusic.cproj
index 0ab48be..34cd8d5 100644
--- a/floppyMusic/floppyMusic.cproj
+++ b/floppyMusic/floppyMusic.cproj
@@ -82,39 +82,39 @@
   <PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
     <ToolchainSettings>
       <AvrGcc>
-  <avrgcc.common.Device>-mmcu=atmega32 -B "%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\gcc\dev\atmega32"</avrgcc.common.Device>
-  <avrgcc.common.outputfiles.hex>True</avrgcc.common.outputfiles.hex>
-  <avrgcc.common.outputfiles.lss>True</avrgcc.common.outputfiles.lss>
-  <avrgcc.common.outputfiles.eep>True</avrgcc.common.outputfiles.eep>
-  <avrgcc.common.outputfiles.srec>True</avrgcc.common.outputfiles.srec>
-  <avrgcc.common.outputfiles.usersignatures>False</avrgcc.common.outputfiles.usersignatures>
-  <avrgcc.compiler.general.ChangeDefaultCharTypeUnsigned>True</avrgcc.compiler.general.ChangeDefaultCharTypeUnsigned>
-  <avrgcc.compiler.general.ChangeDefaultBitFieldUnsigned>True</avrgcc.compiler.general.ChangeDefaultBitFieldUnsigned>
-  <avrgcc.compiler.symbols.DefSymbols>
-    <ListValues>
-      <Value>NDEBUG</Value>
-    </ListValues>
-  </avrgcc.compiler.symbols.DefSymbols>
-  <avrgcc.compiler.directories.IncludePaths>
-    <ListValues>
-      <Value>%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\include</Value>
-    </ListValues>
-  </avrgcc.compiler.directories.IncludePaths>
-  <avrgcc.compiler.optimization.level>Optimize for size (-Os)</avrgcc.compiler.optimization.level>
-  <avrgcc.compiler.optimization.PackStructureMembers>True</avrgcc.compiler.optimization.PackStructureMembers>
-  <avrgcc.compiler.optimization.AllocateBytesNeededForEnum>True</avrgcc.compiler.optimization.AllocateBytesNeededForEnum>
-  <avrgcc.compiler.warnings.AllWarnings>True</avrgcc.compiler.warnings.AllWarnings>
-  <avrgcc.linker.libraries.Libraries>
-    <ListValues>
-      <Value>libm</Value>
-    </ListValues>
-  </avrgcc.linker.libraries.Libraries>
-  <avrgcc.assembler.general.IncludePaths>
-    <ListValues>
-      <Value>%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\include</Value>
-    </ListValues>
-  </avrgcc.assembler.general.IncludePaths>
-</AvrGcc>
+        <avrgcc.common.Device>-mmcu=atmega32 -B "%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\gcc\dev\atmega32"</avrgcc.common.Device>
+        <avrgcc.common.outputfiles.hex>True</avrgcc.common.outputfiles.hex>
+        <avrgcc.common.outputfiles.lss>True</avrgcc.common.outputfiles.lss>
+        <avrgcc.common.outputfiles.eep>True</avrgcc.common.outputfiles.eep>
+        <avrgcc.common.outputfiles.srec>True</avrgcc.common.outputfiles.srec>
+        <avrgcc.common.outputfiles.usersignatures>False</avrgcc.common.outputfiles.usersignatures>
+        <avrgcc.compiler.general.ChangeDefaultCharTypeUnsigned>True</avrgcc.compiler.general.ChangeDefaultCharTypeUnsigned>
+        <avrgcc.compiler.general.ChangeDefaultBitFieldUnsigned>True</avrgcc.compiler.general.ChangeDefaultBitFieldUnsigned>
+        <avrgcc.compiler.symbols.DefSymbols>
+          <ListValues>
+            <Value>NDEBUG</Value>
+          </ListValues>
+        </avrgcc.compiler.symbols.DefSymbols>
+        <avrgcc.compiler.directories.IncludePaths>
+          <ListValues>
+            <Value>%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\include</Value>
+          </ListValues>
+        </avrgcc.compiler.directories.IncludePaths>
+        <avrgcc.compiler.optimization.level>Optimize for size (-Os)</avrgcc.compiler.optimization.level>
+        <avrgcc.compiler.optimization.PackStructureMembers>True</avrgcc.compiler.optimization.PackStructureMembers>
+        <avrgcc.compiler.optimization.AllocateBytesNeededForEnum>True</avrgcc.compiler.optimization.AllocateBytesNeededForEnum>
+        <avrgcc.compiler.warnings.AllWarnings>True</avrgcc.compiler.warnings.AllWarnings>
+        <avrgcc.linker.libraries.Libraries>
+          <ListValues>
+            <Value>libm</Value>
+          </ListValues>
+        </avrgcc.linker.libraries.Libraries>
+        <avrgcc.assembler.general.IncludePaths>
+          <ListValues>
+            <Value>%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\include</Value>
+          </ListValues>
+        </avrgcc.assembler.general.IncludePaths>
+      </AvrGcc>
     </ToolchainSettings>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
@@ -131,6 +131,7 @@
   <avrgcc.compiler.symbols.DefSymbols>
     <ListValues>
       <Value>DEBUG</Value>
+      <Value>F_CPU=16000000UL</Value>
     </ListValues>
   </avrgcc.compiler.symbols.DefSymbols>
   <avrgcc.compiler.directories.IncludePaths>
@@ -179,12 +180,6 @@
     <Compile Include="music.h">
       <SubType>compile</SubType>
     </Compile>
-    <Compile Include="uart.c">
-      <SubType>compile</SubType>
-    </Compile>
-    <Compile Include="uart.h">
-      <SubType>compile</SubType>
-    </Compile>
   </ItemGroup>
   <Import Project="$(AVRSTUDIO_EXE_PATH)\\Vs\\Compiler.targets" />
 </Project>
\ No newline at end of file
diff --git a/floppyMusic/main.c b/floppyMusic/main.c
index 7583bc8..6256e97 100644
--- a/floppyMusic/main.c
+++ b/floppyMusic/main.c
@@ -5,28 +5,38 @@
  * Author : Jonas
  */ 
 
- #ifndef F_CPU
- #define F_CPU 16000000UL //CPU Running at 16MHz
- #endif
+#define _TEST_MODE
 
 #include <avr/io.h>
 
 #include "floppy.h"
+#include "midi.h"
+
+#ifdef _TEST_MODE
 #include "music.h"
-#include "uart.h"
+#endif
 
 int main(void)
 {
-	uart_init(9600);
 	floppy_setup(&PORTC, &DDRC, &PORTB, &DDRB);
+
+	#ifdef _TEST_MODE //Play imperial March in test mode
+
 	DDRA = 0xff;
-	uart_send_string("Hallo\n");
 
-    while (1) 
+    for(;;)
     {
 		play_imperial_march();
 		_delay_ms(2000);
-		uart_send_string("Hallo\n");
     }
+
+	#else //Normal MIDI mode
+
+	midi_setup();
+
+	for(;;);
+
+	#endif
+
 }
 
diff --git a/floppyMusic/midi.c b/floppyMusic/midi.c
index ff70a95..ae99371 100644
--- a/floppyMusic/midi.c
+++ b/floppyMusic/midi.c
@@ -5,38 +5,126 @@
  *  Author: Jonas
  */ 
 
+ /*
+  Octave||                     Note Numbers
+	 #  ||
+	    || C   | C#  | D   | D#  | E   | F   | F#  | G   | G#  | A   | A#  | B
+ -----------------------------------------------------------------------------
+	 0  ||   0 |   1 |   2 |   3 |   4 |   5 |   6 |   7 |   8 |   9 |  10 | 11
+	 1  ||  12 |  13 |  14 |  15 |  16 |  17 |  18 |  19 |  20 |  21 |  22 | 23
+	 2  ||  24 |  25 |  26 |  27 |  28 |  29 |  30 |  31 |  32 |  33 |  34 | 35
+	 3  ||  36 |  37 |  38 |  39 |  40 |  41 |  42 |  43 |  44 |  45 |  46 | 47
+	 4  ||  48 |  49 |  50 |  51 |  52 |  53 |  54 |  55 |  56 |  57 |  58 | 59
+	 5  ||  60 |  61 |  62 |  63 |  64 |  65 |  66 |  67 |  68 |  69 |  70 | 71
+	 6  ||  72 |  73 |  74 |  75 |  76 |  77 |  78 |  79 |  80 |  81 |  82 | 83
+	 7  ||  84 |  85 |  86 |  87 |  88 |  89 |  90 |  91 |  92 |  93 |  94 | 95
+	 8  ||  96 |  97 |  98 |  99 | 100 | 101 | 102 | 103 | 104 | 105 | 106 | 107
+	 9  || 108 | 109 | 110 | 111 | 112 | 113 | 114 | 115 | 116 | 117 | 118 | 119
+	 10 || 120 | 121 | 122 | 123 | 124 | 125 | 126 | 127 |
+ */
+
 #include "midi.h"
 
-void midi_setup()
-{
-	uart_init(9600);
-}
+extern const uint16_t midi_code_frequency_table[] = {8,9,9,10,10,11,12,12,13,14,15,15,16,17,18,19,21,22,23,25,26,28,29,31,33,35,37,39,41,44,46,49,52,55,58,62,65,69,73,78,82,87,93,98,104,110,117,123,131,139,147,156,165,175,185,196,208,220,233,247,262,277,294,311,330,349,370,392,415,440,466,494,523,554,587,622,659,698,740,784,831,880,932,988,1047,1109,1175,1245,1319,1397,1480,1568,1661,1760,1865,1976,2093,2217,2349,2489,2637,2794,2960,3136,3322,3520,3729,3951,4186,4435,4699,4978,5274,5588,5920,6272};
 
-void midi_recieve(struct midi_command *_command)
+ISR(USART_RXC_vect)
 {
-	if(!(UCSRB & (1<<RXEN))) //Return if UART reciever not enabled
-		return;
-
+	cli();
 	char status, data1, data2;
 	char command, channel, note, velocity;
 
-	status = uart_recieve();
-	data1  = uart_recieve();
-	data2  = uart_recieve();
+	//read data from interface
+	status = midi_recieve();
+	data1  = midi_recieve();
+	data2  = midi_recieve();
 
-	command = status & 0x0f; //Mask out last 4 bits 
+	sei();
+
+	//split data
+	command = status & 0x0f; //Mask out last 4 bits
 	channel = (status >> 4) & 0x0f; // Shift channel into first 4 bits;
 	note = data1;
 	velocity = data2;
 
-	_command->command = command;
-	_command->channel=channel;
-	_command->note = note;
-	_command->velocity = velocity;
+	switch(command)
+	{
+		case 0x08: //Note off
+			midi_update_note(note, 0);
+		break;
+			midi_update_note(note, 1);
+		case 0x09: //Note on
+			
+		break;
+
+		case 0x0A: //Note Fade Out
+			//unused
+		break;
+
+		case 0x0B: //Control Change
+			//unused
+		break;
+
+		case 0x0C: //Channel Fade Out
+			//unused
+		break;
+
+		case 0x0E: //Note Pitch change
+			//unused
+		break;
+	}
+	
 
 }
 
-void midi_send(struct midi_command _command)
+void midi_setup()
 {
+	midi_active_channels = 0x00;
+
+	//UART init
+	unsigned  int ubrr   = (F_CPU / (16 * _MIDI_LINK_SPEED))  - 1;
+
+	UBRRH = (unsigned char) (ubrr>>8) & 0xff;
+	UBRRL = (unsigned char) ubrr & 0xff;
+
+	UCSRB = (1<<RXEN)  | (1<<TXEN);
+	UCSRC = (1<<URSEL) | (1<<USBS) | (3<<UCSZ0);
+
+	UCSRB |= (1<<RXCIE); //enable interrupt
+}
+
+ char midi_recieve()
+ {
+	 while(!(UCSRA & (1<<RXC))); //Wait for data
+
+	 return UDR;
+ }
+
+ void midi_update_note(uint16_t _note, uint8_t _status)
+ {
+	if(_status) //Note on
+	{
+		int i;
+		for(i = 0; i < 8; i++) //search for first free channel
+			if(!(midi_active_channels & (1<<i)))
+				break;
+
+		midi_current_notes[i] = _note; //write current note to channel
+		midi_active_channels |= (1<<i); //set channel active
+		floppy_set_frequency(i, floppy_calc_freq(midi_code_frequency_table[_note]) ); //play note
+	}
 
-}
\ No newline at end of file
+	else //Note off
+	{
+		int i;
+		for(i = 0; i < 8; i++) //search for active channel playing _note
+		{
+			if(midi_current_notes[i] == _note)
+			{
+				floppy_set_frequency(i, 0); //mute
+				midi_current_notes[i] = 0xff; //unset current, 0xff is outside MIDI standards
+				midi_active_channels &= ~(1<<i); //unset channel active
+				break;
+			}
+		}
+	}
+ }
diff --git a/floppyMusic/midi.h b/floppyMusic/midi.h
index f30f1c4..733fe05 100644
--- a/floppyMusic/midi.h
+++ b/floppyMusic/midi.h
@@ -5,30 +5,41 @@
  *  Author: Jonas
  */ 
 
+#ifndef F_CPU
+#error F_CPU not defined for midi.h
+#endif
 
 #ifndef MIDI_H_
 #define MIDI_H_
 
-#define _MIDI_SEND 0
-#define _MIDI_RECIEVE 1
+#define _MIDI_LINK_SPEED 30000UL //Standard MIDI linkspeed is 30k baud
 
-#include "uart.h"
 
-struct midi_command
-{
-	char command;
-	char channel;
-	char note;
-	char velocity;
-};
 
+#include <avr/interrupt.h>
+#include <avr/io.h>
 
-void midi_setup();
+#include "floppy.h"
+
+char midi_active_channels;
+uint16_t midi_current_notes[8];
+const uint16_t midi_code_frequency_table[232];
 
-void midi_recieve(struct midi_command *_command);
+void midi_setup();
+/*
+* initializes UART communication and Interrupts
+*/
 
-void midi_send(struct midi_command _command);
+void midi_update_note(uint16_t _note, uint8_t _status);
+/*
+* _note : MIDI standard note #
+* _status : 0=OFF >0=ON
+*/
 
+char midi_recieve();
+/*
+* reads UART recieve buffer 
+*/
 
 
 #endif /* MIDI_H_ */
\ No newline at end of file
diff --git a/floppyMusic/uart.c b/floppyMusic/uart.c
deleted file mode 100644
index 3aac221..0000000
--- a/floppyMusic/uart.c
+++ /dev/null
@@ -1,45 +0,0 @@
-/*
- * uart.c
- *
- * Created: 02.05.2017 20:48:26
- *  Author: Jonas
- */ 
-
- #include "uart.h"
-
- void uart_init(unsigned int _baud)
- {
-	unsigned  int ubrr =  (F_CPU / (16 * _baud))  - 1;
-
-	 UBRRH = (unsigned char)(ubrr>>8) & 0xff;
-	 UBRRL = (unsigned char)ubrr & 0xff;
-
-	 UCSRB = (1<<RXEN)|(1<<TXEN);
-	 UCSRC = (1<<URSEL)|(1<<USBS)|(3<<UCSZ0);
- }
-
- void uart_send(char _data)
- {
-	 while(!(UCSRA & (1<<UDRE))); //Wait for previous data to be sent
-	 UDR = _data;
- }
-
- void uart_send_string(char *_data)
- {
-	 char *data = _data;
-
-	 while(*data != '\0')
-	 {
-		 uart_send(*data);
-		 data++;
-	 }
- }
-
- char uart_recieve()
- {
-	 while(!(UCSRA & (1<<RXC))); //Wait for data
-
-	 return UDR;
- }
-
-
diff --git a/floppyMusic/uart.h b/floppyMusic/uart.h
deleted file mode 100644
index 1954357..0000000
--- a/floppyMusic/uart.h
+++ /dev/null
@@ -1,30 +0,0 @@
-/*
- * uart.h
- *
- * Created: 02.05.2017 20:48:16
- *  Author: Jonas
- */ 
-
-
-#ifndef UART_H_
-#define UART_H_
-
-#ifndef F_CPU
-#define F_CPU 16000000UL //CPU Running at 16MHz
-#endif
-
-#include <avr/io.h>
-
-
-#define _GET_UBBR(BAUD) ( (F_CPU / 16 * BAUD) - 1)
-
-void uart_init(unsigned int _baud);
-
-void uart_send(char _data);
-
-void uart_send_string(char *_data);
-
-char uart_recieve(void);
-
-
-#endif /* UART_H_ */
\ No newline at end of file