Changeset e07597b in avrstuff

Timestamp:

Jan 14, 2012, 9:54:32 PM (12 years ago)

Author:

Adrien Destugues <pulkomandy@…>

Branches:

main

Children:

e69146a

Parents:

4af90bf

Message:

• Remove binary file for now
• Make sure the output stays high when not generating pulses, and also stop the timer to get no interrupt storm.

git-svn-id: ​svn://pulkomandy.tk/avrstuff@52 c6672c3c-f6b6-47f9-9001-1fd6b12fecbe

Location:

V-USB_Dev/firmwares/CrO2

Files:

• main.c (modified) (5 diffs)
• starkadroid.hex (deleted)

V-USB_Dev/firmwares/CrO2/main.c

@@ -35 +35 @@
         readPos = 0;
 
+        // Generate sync header (this never changes)
+        int i;
+        for (i = 0; i< 16; i++)
+        {
+                ioblock[i] = 1;
+        }
+        ioblock[i++] = 0x3C;
+        ioblock[i++] = 0x5A;
+
+        // HEAD block
+        ioblock[i++] = 0x0;
+        ioblock[i++] = 0x10;
+
+        int j = i;
+        ioblock[i++] = 'C';
+        ioblock[i++] = 'r';
+        ioblock[i++] = 'O';
+        ioblock[i++] = '2';
+        ioblock[i++] = ' ';
+        ioblock[i++] = ' ';
+        ioblock[i++] = ' ';
+        ioblock[i++] = ' ';
+        ioblock[i++] = 'B';
+        ioblock[i++] = 'A';
+        ioblock[i++] = 'S';
+        ioblock[i++] = 0;
+        ioblock[i++] = 0;
+        ioblock[i++] = 0;
+        uint8_t s = 0;
+        for (;j<i;j++) s -= ioblock[j];
+        ioblock[i++] = s;
+
+
         // Setup TIMER 1 for MFM pulses generation
         TCCR1A = (1<<COM1A0); // Enable OC1A output
+        TCCR1A |= (1<<COM1A1); // Compare match will always SET OC1A instead of toggling it. Thus the output is always high.
         // CTC mode with OCR1A as MAXregister
-        TCCR1B = (1<<WGM12) | (1<<CS10);
+        TCCR1B = (1<<WGM12);
         OCR1A = 12800; // 800us bit clock
         OCR1B = 6400; // Half-clock for 1 bits
         TIMSK = (1 << OCIE1B) | (1 << OCIE1A); // interrupts on both timer matches.
+        TCCR1A |= (bit << FOC1A); // Force toggle of A (make sure output is a logic 1 to allow MO5 to detect tapedrive)
 
-        // TODO only start the timer when actually needed (start of block)
-        // and stop it when done.
         DDRB |= 2; // OC1A/PB1 as output
 
@@ -51 +84 @@
                 wdt_reset();
                 usbPoll();
-
-                // TODO send data to tape !
+                // TODO watch for motor on/off
         }
 }
@@ -91 +123 @@
         {
                 // TODO leave place for sync header and block type+size
-                ioblock[writePos++] = data[i];
+//              ioblock[writePos] = data[i];
+                writePos++;
         }
 
         // TODO compute checksum as we go
 
-        return writePos>= blksz ? 1:0;
+        if (writePos >= blksz)
+        {
+                // start generating
+                TCCR1A &= ~(1<<COM1A1);
+                TCCR1B |= (1<<CS10);
+                return 1;
+        } else {
+                return 0;
+        }
         // returns 0: "needs more data"
         // returns 1: "done"
@@ -102 +143 @@
 }
 
-ISR (TIMER1_COMPA_vect)
+ISR (TIMER1_COMPA_vect, ISR_NOBLOCK)
 {
         // generate next bit
@@ -111 +152 @@
                 bitpos = 0;
                 readPos++;
-                if (readPos > 270)
-                        readPos = 0; // TODO stop timer
+                if (readPos > blksz)
+                {
+                        // Make sure output is high
+                        TCCR1A |= (1<<COM1A1);
+                        // Stop generating (and interrupts)
+                        TCCR1B &= ~(1<<CS10);
+                        readPos = 0;
+                        TCCR1A |= (1 << FOC1A);
+                }
         }
 }
 
-ISR (TIMER1_COMPB_vect)
+ISR (TIMER1_COMPB_vect, ISR_NOBLOCK)
 {
         TCCR1A |= (bit << FOC1A); // Force toggle of A on B compare when generating a 1 bit