work from lab

final_project/sd_reader/comms.h

@@ -1 +1,81 @@
-../comms/comms.h
+#ifndef COMMS_H_
+#define COMMS_H_
+
+#include <avr/io.h>
+#include <string.h>
+
+
+/**
+ * Our format goes like this:
+ * 
+ * 1 byte command, with data after
+ */
+
+
+typedef enum {
+    COMMS_CMD_CLR = 0U,         //! Clears LCD and all file names
+    COMMS_CMD_NUM,              //! sends the total number of songs to choose from
+	COMMS_CMD_QUERY_NUM,
+    COMMS_CMD_QUERY_NAME,       //! Queries for the name of a given song ID
+    COMMS_CMD_REPLY_NAME,       //! Responds with the name of the given song ID
+    COMMS_CMD_SELECT_FILE,      //! selects a file from the given list to play, data is 1 byte for id
+    COMMS_CMD_PLAY,             //! Starts playing file
+    COMMS_CMD_PAUSE             //! pauses playing file
+} comms_cmd_t;
+
+/** @brief Inline function to send commands and values.
+ */
+inline void comms_send(comms_cmd_t cmd) {
+
+    while (! (UCSR0A & (1 << UDRE0)));
+    UDR0 = cmd;
+}
+
+/** @brief Selects a file from the list on the DAC side.
+ * 
+ * If another song is playing, this will stop
+ * that song from playing and select the new one.
+ */
+inline void comms_select_file(uint8_t id) {
+    comms_send(COMMS_CMD_SELECT_FILE);
+    comms_send((comms_cmd_t) id);
+}
+
+/** @brief Queries for the name of the given song ID.
+ */
+inline void comms_query_name(uint8_t id) {
+    comms_send(COMMS_CMD_QUERY_NAME);
+    comms_send(id);
+}
+
+/** @brief Repliers with the name of the requsted song ID
+ */
+inline void comms_reply_name(char* name) {
+    uint8_t len = strlen(name);
+    comms_send(COMMS_CMD_REPLY_NAME);
+    comms_send(len);
+
+    for (uint8_t i = 0; i < len; i++) {
+        comms_send((uint8_t) name[i]);
+    }
+}
+
+/** @brief Clears the LCD list of files.
+ */
+inline void comms_clear() {
+    comms_send(COMMS_CMD_CLR);
+}
+
+/** @brief Starts playing song.
+ */
+inline void comms_play() {
+    comms_send(COMMS_CMD_PLAY);
+}
+
+/** @brief Pauses playing song.
+ */
+inline void comms_pause() {
+    comms_send(COMMS_CMD_PLAY);
+}
+
+#endif

final_project/sd_reader/main.c

@@ -20,13 +20,15 @@ uint8_t cmd_state;
 
 // Song playing
 // TODO fix this atrocious naming
-uint16_t song_buf[2][SONG_BUF_LEN]; //! Buffers to play song from
+uint8_t song_buf[2][SONG_BUF_LEN]; //! Buffers to play song from
 uint8_t song_position;              //! where we are in the buffers
 bool song_buf_select;               //! which buffer we're using
 bool song_selected;                 //! Flag to say we just selected the song, read data in
 int8_t song_selection = -1;         //! ID of selected song
 uint32_t song_len;
 uint32_t song_read_position;
+bool send_number_of_songs = true;
+uint8_t num_songs = 0;
 
 
 typedef struct {
@@ -41,6 +43,7 @@ int main()
     gpio_init();
     timer_init();
     usart_init();
+	sei();
 
     // TODO set SPI to highest freq possible, might just need tweaking
     sd_raw_init();
@@ -102,8 +105,12 @@ int main()
             song_id++;
         }
 		
+
     }
 	
+	num_songs = song_id;
+	
+	
     // Print out all files/directories in top level
     while (1) {
         /// do stuff
@@ -133,6 +140,10 @@ int main()
                         // Wait for next loop to handle file info
                         cmd_depth = 1;
                         break;
+					case (COMMS_CMD_QUERY_NUM):
+						comms_send(COMMS_CMD_NUM);
+						comms_send(num_songs);
+						break;
                 }
             }
 
@@ -140,18 +151,17 @@ int main()
 
         if (cmd_depth == 1) {
             uint8_t song_id;
-            if (fifo_pop(&song_id) == FIFO_SUCCESS) {
+            while (fifo_pop(&song_id) != FIFO_SUCCESS);
-                switch (cmd_state) {
+            switch (cmd_state) {
-                    case (COMMS_CMD_SELECT_FILE):
+                case (COMMS_CMD_SELECT_FILE):
-                        // select proper song and begin reading in
+                    // select proper song and begin reading in
-                        song_selection = song_id;
+                    song_selection = song_id;
-                        song_selected = 1;
+                    song_selected = 1;
-                        break;
+                    break;
-                    case (COMMS_CMD_QUERY_NAME):
+                case (COMMS_CMD_QUERY_NAME):
-                        // Just going to hope we can bump the UART baudrate up high enough
+                    // Just going to hope we can bump the UART baudrate up high enough
-                        comms_reply_name(songs[song_id].name);
+                    comms_reply_name(songs[song_id].name);
-                        break;
+                    break;
-                }
             }
         }
 
@@ -192,7 +202,7 @@ int main()
 
                 // We are now at the actual data
                 // divide by two to get uint16
-                song_len = header.cksize / 2;
+                song_len = header.cksize;
                 song_read_position = 0;
             }
 
@@ -206,7 +216,7 @@ int main()
             
             // Read in file
             // 512 bytes to read, 256 samples
-            fat_read_file(songs[song_selection].fd, (uint8_t*) song_buf[read_song_buf], 512);
+            fat_read_file(songs[song_selection].fd, (uint8_t*) song_buf[read_song_buf], 256);
             song_read_position += 256;
 
             // If we selected the song, make sure we start playing from the right buffer

final_project/sd_reader/main.h

@@ -1,11 +1,15 @@
 #ifndef MAIN_H_
 #define MAIN_H_
 
+#define F_CPU 8000000UL
+
 #include <string.h>
 #include <stdlib.h>
 #include <stdbool.h>
 #include <avr/pgmspace.h>
 #include <avr/sleep.h>
+#include <avr/interrupt.h>
+#include <util/delay.h>
 #include "fat.h"
 #include "fat_config.h"
 #include "partition.h"
@@ -21,8 +25,9 @@
 
 
 // Song playing
-extern uint16_t song_buf[2][SONG_BUF_LEN];  //! Buffers to play song from
+extern uint8_t song_buf[2][SONG_BUF_LEN];  //! Buffers to play song from
 extern uint8_t song_position;               //! where we are in the buffers
 extern bool song_buf_select;                //! which buffer we're using
+extern bool send_number_of_songs;
 
 #endif

final_project/sd_reader/periph.c

@@ -4,14 +4,15 @@
 /** @brief intercepts incoming Serial commands
  */
 ISR(USART_RX_vect) {
+
     cli();
     // Read byte into FIFO
-    fifo_push(UDR0);
+	uint8_t in_byte = UDR0;
+    fifo_push(in_byte);
 
     // Flag is cleared by reading data from UDR
     sei();
 }
-
 /** @brief Interrupt handler for actually playing music
  * 
  * Will only be called if the TIFR OCF0A flag is high, using that as our play/pause flag
@@ -29,19 +30,11 @@ ISR(TIMER0_COMPA_vect) {
      * 
      * DAC12 and DAC13 are PB0 and PB1
      */
-    uint16_t in_data = song_buf[song_buf_select][song_position];
+    uint8_t in_data = song_buf[song_buf_select][song_position];
-    // Split into 8 bit because we are using an 8 bit MCU, so code can be better
-    uint8_t data_lo = in_data;
-    uint8_t data_hi = in_data >> 8;
-
     // DAC0 -> DAC5
-    PORTC = (data_lo >> 2) & 0x3F;
     // DAC6 -> DAC11
-    PORTD &= 0x03;
+    PORTD &= in_data & 0xFC;
-    PORTD |= data_hi << 2;
+	PORTB &= in_data & 0x03;
-    // DAC12 and DAC13
-    PORTB &= 0xFC; // clear bits
-    PORTB |= data_hi >> 6;
 
     // Go to next sample
     song_position++;
@@ -66,7 +59,7 @@ void gpio_init() {
 void timer_init() {
     // Compare outputs should be default, nothing
     // Set to CTC, WGM = 0b010
-    TCCR0A = (1 << OCIE0A);
+    TCCR0A = (1 << WGM01);
 
     // Set timer to use clock input w/o prescaling
     TCCR0B = 1;
@@ -76,16 +69,21 @@ void timer_init() {
     OCR0A = 182;
 
     // Don't enable the interrupt yet
+	
 }
 
 void usart_init() {
     // set baudrate
     UBRR0L = UBRR_VALUE & 255;
     UBRR0H = UBRR_VALUE >> 8;
+	   // Start it up
+    UCSR0B |= (1 << TXEN0) | (1 << RXEN0);
 
     // Set data info, no parity, 1 stop, 8-bit
     UCSR0C |= (1 << UCSZ01) | (1 << UCSZ00);
 
-    // Start it up
+ 
-    UCSR0B |= (1 << TXEN0) | (1 << RXEN0);
+	
+	// Enable interrupt
+	UCSR0B |= (1 << RXCIE0);
 }