From d7c4299cd4aaaabcce3c5d6eab3a4f693dd784cc Mon Sep 17 00:00:00 2001
From: Jonas Gunz <himself@jonasgunz.de>
Date: Sat, 22 Jul 2017 12:22:52 +0200
Subject: midi input handling redone

---
 floppyMusic/midi.c | 107 +++++++++++++++++++++++++++++++++--------------------
 1 file changed, 66 insertions(+), 41 deletions(-)

(limited to 'floppyMusic/midi.c')

diff --git a/floppyMusic/midi.c b/floppyMusic/midi.c
index ca32d5a..8e760a8 100644
--- a/floppyMusic/midi.c
+++ b/floppyMusic/midi.c
@@ -7,53 +7,65 @@
 
 #include "midi.h"
 
-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};
+static 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};
+
+static uint8_t midi_recv_ptr = 0;
 
 ISR(USART_RXC_vect)
 {
-	char data[3] = {0x00, 0x00, 0x00};
-	char command, /*channel,*/ note/*, velocity*/;
+	midi_recv_buffer[midi_recv_ptr] = UDR;
+	midi_recv_ptr++;
+}
 
-	UCSRB &= ~(1<<RXCIE);//Disable UART interrupt
+void midi_setup()
+{
+	midi_active_channels = 0x00;
+	DDRA = 0xff;
+	PORTA = 0xff;
+	//UART init
+	unsigned  int ubrr   = (F_CPU / (16 * _MIDI_LINK_SPEED))  - 1;
 
-	//read data from interface
-	while(!(UCSRA & (1<<RXC))); //Wait for data
-	data[0] = UDR;
+	UBRRH = (unsigned char) (ubrr>>8) & 0xff;
+	UBRRL = (unsigned char) ubrr & 0xff;
 
-	for(int i = 0; i < 20; i++) { //Wait 100µs for next datapackage
-		_delay_us(1);
-		if((UCSRA & (1<<RXC))) {
-			data[1] = UDR;
-			break;
-		}
-	}
-	for(int i = 0; i < 20; i++) {
-		_delay_us(1);
-		if((UCSRA & (1<<RXC))) {
-			data[2] = UDR;
-			break;
-		}
-	}
-	UCSRB |= (1<<RXCIE);//reenable UART Interrupt
+	UCSRB = (1<<RXEN)  | (1<<TXEN) | (1<<RXCIE); //Enable Tx, Rx and Rx Interrupt
+	UCSRC = (1<<URSEL) | (1<<USBS) | (3<<UCSZ0);
+
+}
+
+void midi_process()
+{
+	if(!midi_recv_avail())
+		return;
+
+	char data[3] = {0x00, 0x00, 0x00};
+	char command, /*channel,*/ note, velocity;
+
+	data[0] = midi_get_recv_buf();
+	data[1] = midi_get_recv_buf();
+	data[2] = midi_get_recv_buf();
 
-	//split data
 	/*channel = data[0] & 0x0f; //Mask out last 4 bits*/
 	command = (data[0] >> 4) & 0x0f; // Shift command into first 4 bits;
 	note = data[1];
-	/*velocity = data2;*/
-	
-	//PORTA = ~command;
-	
-	switch(command)
+	velocity = data[2];
+
+	midi_command(command, note, velocity);
+
+}
+
+void midi_command(char _cmd, char _note, char _vel)
+{
+	switch(_cmd)
 	{
 		case 0x08: //Note off
 			PORTA = 1;
-			midi_update_note(note, 0);
+			midi_update_note(_note, 0);
 		break;
 			
 		case 0x09: //Note on
 			PORTA = 2;
-			midi_update_note(note, 1);
+			midi_update_note(_note, 1);
 		break;
 		/*
 		case 0x0A:break; //Note Fade Out
@@ -68,23 +80,25 @@ ISR(USART_RXC_vect)
 	}
 }
 
-void midi_setup()
+uint8_t midi_recv_avail()
 {
-	midi_active_channels = 0x00;
-	DDRA = 0xff;
-	PORTA = 0xff;
-	//UART init
-	unsigned  int ubrr   = (F_CPU / (16 * _MIDI_LINK_SPEED))  - 1;
+	return midi_recv_ptr;
+}
 
-	UBRRH = (unsigned char) (ubrr>>8) & 0xff;
-	UBRRL = (unsigned char) ubrr & 0xff;
+char midi_get_recv_buf()
+{
+	if(midi_recv_ptr > 0)
+		midi_recv_ptr--;
+	else
+		return 0x00;
 
-	UCSRB = (1<<RXEN)  | (1<<TXEN) | (1<<RXCIE); //Enable Tx, Rx and Rx Interrupt
-	UCSRC = (1<<URSEL) | (1<<USBS) | (3<<UCSZ0);
 
+	return midi_recv_buffer[midi_recv_ptr];
 }
 
- void midi_update_note(uint16_t _note, uint8_t _status)
+
+
+void midi_update_note(uint16_t _note, uint8_t _status)
  {
 	if(_status) //Note on
 	{
@@ -113,3 +127,14 @@ void midi_setup()
 		}
 	}
  }
+
+
+void midi_uart_out(unsigned char _c)
+ {
+
+	/* Wait for empty transmit buffer */
+	while ( !( UCSRA & (1<<UDRE)) )
+	;
+	/* Put data into buffer, sends the data */
+	UDR = _c;
+ }
-- 
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