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Diffstat (limited to 'avr_libs/uartlib/test_uart.c')
| -rw-r--r-- | avr_libs/uartlib/test_uart.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/avr_libs/uartlib/test_uart.c b/avr_libs/uartlib/test_uart.c new file mode 100644 index 0000000..44346b0 --- /dev/null +++ b/avr_libs/uartlib/test_uart.c @@ -0,0 +1,130 @@ +/*************************************************************************
+Title: example program for the Interrupt controlled UART library
+Author: Peter Fleury <pfleury@gmx.ch> http://jump.to/fleury
+File: $Id: test_uart.c,v 1.4 2005/07/10 11:46:30 Peter Exp $
+Software: AVR-GCC 3.3
+Hardware: any AVR with built-in UART, tested on AT90S8515 at 4 Mhz
+
+DESCRIPTION:
+ This example shows how to use the UART library uart.c
+
+*************************************************************************/
+#include <stdlib.h>
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <avr/signal.h>
+#include <avr/pgmspace.h>
+
+#include "uart.h"
+
+
+/* define CPU frequency in Mhz here if not defined in Makefile */
+#ifndef F_CPU
+#define F_CPU 4000000UL
+#endif
+
+/* 9600 baud */
+#define UART_BAUD_RATE 9600
+
+
+int main(void)
+{
+ unsigned int c;
+ char buffer[7];
+ int num=134;
+
+
+ /*
+ * Initialize UART library, pass baudrate and AVR cpu clock
+ * with the macro
+ * UART_BAUD_SELECT() (normal speed mode )
+ * or
+ * UART_BAUD_SELECT_DOUBLE_SPEED() ( double speed mode)
+ */
+ uart_init( UART_BAUD_SELECT(UART_BAUD_RATE,F_CPU) );
+
+ /*
+ * now enable interrupt, since UART library is interrupt controlled
+ */
+ sei();
+
+ /*
+ * Transmit string to UART
+ * The string is buffered by the uart library in a circular buffer
+ * and one character at a time is transmitted to the UART using interrupts.
+ * uart_puts() blocks if it can not write the whole string to the circular
+ * buffer
+ */
+ uart_puts("String stored in SRAM\n");
+
+ /*
+ * Transmit string from program memory to UART
+ */
+ uart_puts_P("String stored in FLASH\n");
+
+
+ /*
+ * Use standard avr-libc functions to convert numbers into string
+ * before transmitting via UART
+ */
+ itoa( num, buffer, 10); // convert interger into string (decimal format)
+ uart_puts(buffer); // and transmit string to UART
+
+
+ /*
+ * Transmit single character to UART
+ */
+ uart_putc('\r');
+
+ for(;;)
+ {
+ /*
+ * Get received character from ringbuffer
+ * uart_getc() returns in the lower byte the received character and
+ * in the higher byte (bitmask) the last receive error
+ * UART_NO_DATA is returned when no data is available.
+ *
+ */
+ c = uart_getc();
+ if ( c & UART_NO_DATA )
+ {
+ /*
+ * no data available from UART
+ */
+ }
+ else
+ {
+ /*
+ * new data available from UART
+ * check for Frame or Overrun error
+ */
+ if ( c & UART_FRAME_ERROR )
+ {
+ /* Framing Error detected, i.e no stop bit detected */
+ uart_puts_P("UART Frame Error: ");
+ }
+ if ( c & UART_OVERRUN_ERROR )
+ {
+ /*
+ * Overrun, a character already present in the UART UDR register was
+ * not read by the interrupt handler before the next character arrived,
+ * one or more received characters have been dropped
+ */
+ uart_puts_P("UART Overrun Error: ");
+ }
+ if ( c & UART_BUFFER_OVERFLOW )
+ {
+ /*
+ * We are not reading the receive buffer fast enough,
+ * one or more received character have been dropped
+ */
+ uart_puts_P("Buffer overflow error: ");
+ }
+ /*
+ * send received character back
+ */
+ uart_putc( (unsigned char)c );
+ }
+ }
+
+}
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