1 files changed, 72 insertions, 36 deletions

diff --git a/src/main.c b/src/main.c
index 2252277..9a53169 100644
--- a/src/main.c
+++ b/src/main.c
@@ -87,12 +87,25 @@
 #include <stdint.h>
 #include <string.h>
 
-#define NOTES 15 
-#define NOTE_MASK 0xFF00
+
+#define NOTE_MIN_LENGTH_MS 10
+#define NOTE_MASK 0xFFFFFF00
+
+#define NOTES 16
+
+#define MIDI_CHANNEL 0x0
+#define MIDI_SCALE_START 0x34 // note C3, C4 is 0x3C
+#define MIDI_NOTE_SPEED 0x0F // max is 0x7F
+
+
+#define DEBUG
+
 
 
 /* global variables */
-volatile uint16_t keypresses[NOTES];
+volatile uint32_t keys_data[NOTES];
+// flags to notify the main program
+volatile uint16_t keypresses = 0;
 
 /* function prototypes */
 int eusart_write_midi(const midi_message_t *pkt);
@@ -100,35 +113,33 @@ int eusart_write_midi(const midi_message_t *pkt);
 /* interrupt service routine */
 interrupt void isr(void)
 {
-    unsigned char i, data;
+    unsigned char i, data_a, data_b;
 
     PORTDbits.RD3 = 0;
     
     if (PIR1bits.TMR2IF) {
-        // PORTA
-        data = PORTA;
+        data_a = PORTA;
+        data_b = PORTB;
         i = 7;
         do {
-            keypresses[i] = (keypresses[i] << 1) | ((data >> i) & 0x01);
+            // read the data and append it at the end of keys_data[i]
+            keys_data[i] = (keys_data[i] << 1) | ((data_a >> i) & 0x01);
+            keys_data[i + 8] = (keys_data[i + 8] << 1) | ((data_b >> i) & 0x01);
+
+            // TODO same for PORTD when the steps board is printed
+
+            // set flags
+            keypresses |= (keys_data[i] && !(keys_data[i] & NOTE_MASK))<<i;
+            keypresses |= (keys_data[i + 8] && !(keys_data[i + 8] & NOTE_MASK))<<(i + 8);
+
         } while (i--);
         
-        data = PORTB;
-        i = 7;
-        do {
-            keypresses[i] = (keypresses[i] << 1) | ((data >> i) & 0x01);
-        } while (i-- - 8);
-        
-        // PORTB
-        // for (i = 8; i < NOTES; i++) {
-        //     keypresses[i] = (keypresses[i] << 1) | ((PORTB & (1 << i)) >> i);
-        // }
-        
-        // TODO same for PORTD when the steps board is printed
-        
+#ifdef DEBUG
         // debug stuff
         PORTDbits.RD4 = PORTAbits.RA0;
-        PORTDbits.RD2 = (keypresses[0] && !(keypresses[0] & NOTE_MASK));
-
+        PORTDbits.RD2 = (keys_data[0] && !(keys_data[0] & NOTE_MASK));
+#endif
+        
         // reset interrupt flag
         PIR1bits.TMR2IF = 0;
     }
@@ -158,10 +169,11 @@ inline void init_hw(void)
     ANSELC = 0x00;
     ANSELD = 0x00;
 
-    // TODO: remove demo
+    // set ports as input
     TRISA = 0xFF;
     TRISB = 0xFF;
     
+#ifdef DEBUG
     TRISDbits.TRISD1 = 0;
     TRISDbits.TRISD2 = 0;
     TRISDbits.TRISD3 = 0;
@@ -175,12 +187,13 @@ inline void init_hw(void)
     PORTDbits.RD3 = 1;
     // TEST OUTPUT 3
     PORTDbits.RD4 = 0;
-
+#endif 
+    
     /* timer configuration */
     // timer 2 comp value
     PR2 = 128;
-    // postscaler 1:4
-    T2CONbits.T2OUTPS = 0b0011;
+    // postscaler 1:2
+    T2CONbits.T2OUTPS = 0b0001;
     // prescaler 1:16
     T2CONbits.T2CKPS = 0b11;
     // start timer
@@ -195,30 +208,53 @@ inline void init_hw(void)
     
     /* serial configuration */
     eusart1_init();
-
-    ei();
+    eusart2_init();
 }
 
 
 /* main program */
 void main(void)
 {
-    unsigned char i, data;
-    midi_message_t sample_message;
+    unsigned i;
+    midi_message_t message;
     
     /* setup hardware */
     init_hw();
    
     /* setup software */
-    memset(keypresses, 0, sizeof(keypresses));
+    memset(keys_data, 0, sizeof(keys_data));
     
-    /* TODO remove demo code */
-    midi_note_on(&sample_message, 0x0, 0x3C, 0x7F); 
+    ei();
+    
+#ifdef DEBUG
     PORTDbits.RD1 = 0;
+#endif
+    
+    midi_note_on(&message, MIDI_CHANNEL, MIDI_SCALE_START, MIDI_NOTE_SPEED);
     
     /* main loop */
     while (1) {
-        eusart_write_midi(&sample_message);
+        // check flags
+        for (i = 0; i < NOTES; i++) {
+            if (keypresses & (1<<i)) {
+                
+                // dirty hack to avoid the slow call stack, correct version commented below
+                message.data[0] = MIDI_SCALE_START + i;
+                // midi_note_on(&message, MIDI_CHANNEL, MIDI_SCALE_START + i, 0x7F);
+
+                eusart_write_midi(&message);
+                
+                // wait for the minimum note length
+                
+                // TODO improve;
+                // with this system packets will be delayed by
+                // NOTE_MIN_LENGTH_MS * NOTES milliseconds relative to the actual measurement
+                __delay_ms(NOTE_MIN_LENGTH_MS);
+                
+                // unset flag
+                keypresses &= ~(1<<i);
+            }
+        }
     }
 }
 
@@ -235,10 +271,10 @@ int eusart_write_midi(const midi_message_t *pkt)
     length = pkt->data_size;
     data = (uint8_t *) pkt->data;
     
-    putch((char)((pkt->status << 4) | pkt->channel));
+    eusart2_putch((char)((pkt->status << 4) | pkt->channel));
     
     while (length--) {
-        putch((char) *(data++));
+        eusart2_putch((char) *(data++));
     }
     
     return 0;