printer: avr: Implement protocol with kernel driver

printer/avr/main.c

@@ -5,6 +5,7 @@
 #include <avr/pgmspace.h>
 
 #define BAUDRATE 19200
+//#define DEBUG_BUILD DEBUG_BUILD
 
 /* System functions */
 /* Timers */
@@ -53,8 +54,7 @@ void uart_putc(char c)
 	UDR = c;
 }
 
-#define ENABLE_SERIAL_DEBUG
+#ifdef DEBUG_BUILD
-#ifdef ENABLE_SERIAL_DEBUG
 void debug_putc(char c) {
 	uart_putc(c);
 };
@@ -90,10 +90,20 @@ unsigned int debug_printf(char *format,...) {return 0;};
 
 void hardfault() {
 	cli();
-	debug_write("HARDFAULT!\r\n");
 	PORTB = 0;
 	PORTC = 0;
 	PORTD = 0;
+	uart_putc(0xFF);
+	uart_putc(0xFF);
+	uart_putc(0xFF);
+	uart_putc(0xFF);
+	uart_putc(0xFF);
+	uart_putc(0xFF);
+	uart_putc(0xFF);
+	uart_putc(0x00);
+	uart_putc(0x00);
+	uart_putc(0x00);
+	debug_write("HARDFAULT!\r\n");
 	while(1);
 }
 
@@ -560,16 +570,99 @@ void arm_correction()
 
 #define DCMOTOR_EN MOTLIM(PORT) |= PIN_DCMOTOR
 #define DCMOTOR_STOP MOTLIM(PORT) &= ~PIN_DCMOTOR
-#define DCMOTOR_ISACTIVE (MOTLIM(PORT) & PIN_DCMOTOR)
+#define DCMOTOR_ISACTIVE (!!(MOTLIM(PORT) & PIN_DCMOTOR))
 #define LIMITSWITCH (!(MOTLIM(PIN) & PIN_LIMITSWITCH))
 
+/* Communication Functions */
+#define RINGBUF_CNT(wr,rd) ((wr) - (rd))
+#define RINGBUF_FREE(wr,rd,sz) ((RINGBUF_CNT(rd,wr+1))) // TODO: 255 is actually not correct...
+#define PRINT_BUFFER_SIZE 256 // Important: must be 256 atm, when changed, you need to change code handling print_buffer_*.
+volatile char print_buffer[PRINT_BUFFER_SIZE];
+volatile uint8_t print_buffer_wr = 0;
+volatile uint8_t print_buffer_rd = 0;
+
+#define UART_BYTE_READY (UCSRA & (1 << RXC))
+
+ISR(USART_RXC_vect)
+{
+	if (UCSRA & (1 << RXC)) {
+		print_buffer[print_buffer_wr++] = UDR;// WARNING: No overflow protection
+		// Will auto wrap at 256; print_buffer_wr = print_buffer_wr % PRINT_BUFFER_SIZE;
+	}
+}
+
+#define TX_BUFFER_SIZE 256 // Important: must be 256 atm, when changed, you need to change code handling print_buffer_*.
+char tx_buffer[TX_BUFFER_SIZE];
+uint8_t tx_buffer_wr = 0;
+uint8_t tx_buffer_rd = 0;
+uint8_t tx_buffer_async = 0;
+
+uint8_t global_status;
+#define STATUS_PAPERFEED (1 << 0)
+#define STATUS_CARRIAGE (1 << 1)
+#define STATUS_DAISY (1 << 2)
+#define STATUS_PRINTHEAD (1 << 3)
+#define STATUS_READY (1 << 4)
+#define STATUSBIT_ACTIVE 5
+
+void tx_buffer_putc(char c)
+{
+	if (tx_buffer_async) {
+		if (tx_buffer_rd == tx_buffer_wr + 1) // implicit % 256
+			hardfault();
+		tx_buffer[tx_buffer_wr++] = c; // implicit % 256
+	} else {
+		uart_putc(c);
+	}
+}
+
+void tx_status()
+{
+	unsigned char local_status = 0;
+	local_status |= (DCMOTOR_ISACTIVE << STATUSBIT_ACTIVE);
+
+	tx_buffer_putc(0xFF); /* Header[0] */
+	tx_buffer_putc(0xAA); /* Header[1] */
+	tx_buffer_putc((char) (global_status | local_status));
+	tx_buffer_putc(RINGBUF_FREE(print_buffer_wr, print_buffer_rd, PRINT_BUFFER_SIZE));
+	tx_buffer_putc(0); /* RESERVED */
+	tx_buffer_putc(0); /* RESERVED */
+}
+
+void update_status(uint8_t status)
+{
+	global_status = status;
+
+	tx_status();
+}
+
+void set_status(uint8_t bit)
+{
+	update_status(global_status | bit);
+}
+
+void clear_status(uint8_t bit)
+{
+	update_status(global_status & ~bit);
+}
+
+void tx_buffer_process()
+{
+	if (tx_buffer_rd != tx_buffer_wr) {
+		if (UCSRA & (1 << UDRE)) {
+			UDR = tx_buffer[tx_buffer_rd];
+			tx_buffer_rd++; // implicit % 256
+		}
+	}
+}
 
 /* Initialization Functions */
-
 void move_carriage_to_far_left(uint8_t reset)
 {
 	uint16_t cnt = 0;
 
+	clear_status(STATUS_CARRIAGE);
+
 	/* Init stepper controller */
 	if (reset) {
 		stepper_status_CARRIAGE.step = 0;
@@ -605,6 +698,7 @@ void move_carriage_to_far_left(uint8_t reset)
 	stepper_status_CARRIAGE.target_pos = 0;
 
 	debug_printf("[car] Carriage left after %u steps.\r\n", cnt);
+	set_status(STATUS_CARRIAGE);
 }
 
 void align_daisy_wheel()
@@ -612,6 +706,8 @@ void align_daisy_wheel()
 	int i;
 
 	debug_write("[whl] Aligning wheel...\r\n");
+	clear_status(STATUS_DAISY);
+
 	stepper_status_WHEEL.dir = 0;
 	stepper_status_WHEEL.lpstate = 0;
 	stepper_status_WHEEL.pos = 0;
@@ -651,15 +747,18 @@ void align_daisy_wheel()
 	stepper_status_WHEEL.pos = 0;
 
 	debug_write("[whl] Alignment completed.\r\n");
+	set_status(STATUS_DAISY);
 }
 
 void reset_printhead()
 {
 	debug_write("[hmr] Resetting printhead...\r\n");
+	clear_status(STATUS_PRINTHEAD);
 	DCMOTOR_EN;
 	_delay_ms(200);
 	DCMOTOR_STOP;
 	debug_write("[hmr] Printhead reset completed.\r\n");
+	set_status(STATUS_PRINTHEAD);
 }
 
 void initialize_paperfeed()
@@ -667,6 +766,7 @@ void initialize_paperfeed()
 	int i;
 
 	debug_write("[lfd] Initializing paperfeed...\r\n");
+	clear_status(STATUS_PAPERFEED);
 
 	for (i = 0; i < 10;) {
 		if (block_for(TIM_LINEFEED, STEPPER_CFG_LINEFEED.delay)) {
@@ -684,26 +784,10 @@ void initialize_paperfeed()
 	stepper_status_LINEFEED.ldir = 0;
 
 	debug_write("[lfd] Initialization completed.\r\n");
+	set_status(STATUS_PAPERFEED);
 }
 
 /* Printer Functions */
-
-#define PRINT_BUFFER_SIZE 256 // Important: must be 256 atm, when changed, you need to change code handling print_buffer_*.
-volatile char print_buffer[PRINT_BUFFER_SIZE];
-volatile uint8_t print_buffer_wr = 0;
-volatile uint8_t print_buffer_rd = 0;
-
-#define UART_BYTE_READY (UCSRA & (1 << RXC))
-
-ISR(USART_RXC_vect)
-{
-	if (UCSRA & (1 << RXC)) {
-		print_buffer[print_buffer_wr++] = UDR;// WARNING: No overflow protection
-		// Will auto wrap at 256; print_buffer_wr = print_buffer_wr % PRINT_BUFFER_SIZE;
-	}
-}
-
-
 #define PRINT_CHARACTER_WIDTH 10
 #define PRINT_LINE_HEIGHT 34
 #define PRINTER_STOP_RIGHT 1100
@@ -841,6 +925,7 @@ void printer_process()
 				} else {
 					current_char = print_buffer[print_buffer_rd];
 					print_buffer_rd++;
+					tx_status(); // Tell SoC when bytes are consumed from the buffer. TODO: Too often?
 				}
 			} else {
 				current_char = '\0';
@@ -850,31 +935,30 @@ void printer_process()
 			current_is_linebreak += (current_char == '\n');
 			if (current_is_linebreak) {
 				if (backward) {
-					uart_putc('=');
+					debug_putc('=');
 					print_buffer_rd = print_buffer_recovery;
+					tx_status();
 				}
 				backward = 0; // Re-evaluate backward. Default is forward.
 
 				stepper_status_LINEFEED.target_pos += PRINT_LINE_HEIGHT;
-				uart_putc('\n');
+				debug_putc('\n');
 				current_is_linebreak--;
-				//_delay_ms(1000);
 
 				/* Decide whether we move the carriage back to the left, or
-				 * whether print the new line in reverse. */
+				 * whether to print the new line in reverse. */
 
 				end_of_next_line = print_buffer_rd;
 				temp = simulate_print_run(&end_of_next_line, &print_buffer_recovery);
 
 				if (temp == -1) {
-					//uart_putc('\r');
+					debug_putc('[');
-					uart_putc('[');
 					backward = 1;
 					print_buffer_backward = end_of_next_line;
 
 				} else if (temp == 0) {
 					// do nothing
-					uart_putc('#');
+					debug_putc('#');
 
 				} else {
 					move_carriage_to_left_margin();
@@ -891,7 +975,7 @@ void printer_process()
 				case PRINTER_NO_CHAR:
 					current_is_linebreak += move_one_character(backward);
 					if (!current_is_linebreak)
-						uart_putc(' ');
+						debug_putc(' ');
 					break;
 
 				default: /* It's a printable character */
@@ -912,7 +996,7 @@ void printer_process()
 		if (POSITION_REACHED(WHEEL) && POSITION_REACHED(CARRIAGE) && POSITION_REACHED(LINEFEED)) {
 			arm_hammer();
 			_delay_ms(50); // TODO: replace with timer
-			uart_putc(debug_character);
+			debug_putc(debug_character);
 			current_is_linebreak += move_one_character(backward);
 			state = IDLE;
 		}
@@ -943,7 +1027,16 @@ void printer_process()
 	stepper_perform_movement(&stepper_status_WHEEL, &STEPPER_CFG_WHEEL);
 }
 
+void sync_uart()
+{
+	int i;
+	for (i = 0; i < 10; ++i) {
+		tx_buffer_putc(0xFF);
+	}
+}
+
 /* Test Functions */
+#ifdef DEBUG_BUILD
 void systick_test()
 {
 	debug_write("[tmr] System timer test\r\n");
@@ -1135,11 +1228,17 @@ static void system_test_auto()
 		}
 	}
 }
+#endif
 
 void mainloop()
 {
+	tx_buffer_async = 1;
+	uart_irq_enable(); /* rx buffer process */
+	set_status(STATUS_READY);
+
 	while (1) {
 		printer_process();
+		tx_buffer_process();
 	}
 }
 
@@ -1181,24 +1280,26 @@ int main()
 	TIMSK = (1 << OCIE1A);
 
 	/* Init system */
+	sync_uart();
+	update_status(0);
 	debug_write("\n\n\r[sys] STARTING IO CONTROLLER...\r\n");
 	debug_write("[sys] Enabling interrupts.\r\n");
 	sei();
 
 	/* Align printer */
-	//initialize_paperfeed();
+	initialize_paperfeed();
-	//move_carriage_to_far_left(1);
+	move_carriage_to_far_left(1);
-	//align_daisy_wheel();
+	align_daisy_wheel();
-	//reset_printhead();
+	reset_printhead();
 
 	debug_write("[sys] Startup completed.\r\n");
 
 	/* Run system */
+#ifdef DEBUG_BUILD
 	system_test_auto();
-	// mainloop();
+#else
-	//	printer_test();
+	mainloop();
-	//	system_test_auto();
+#endif
-	//	systick_test();
 
 	debug_write("[sys] REACHED END OF MAIN. HALTING.\r\n");
 	while (1);