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/*
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serial.c - Functions for using the RS232 serial port
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authors: Robotics Club, Colony Project, pkv
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much code taken from FWR's library, author: Tom Lauwers
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*/
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#include <avr/io.h> |
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#include <stdio.h> |
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#include "serial.h" |
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FILE *usb_fd; //For use with fprintf() and related stdio functions
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FILE *xbee_fd; //For use with fprintf() and related stdio functions
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/**
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* Initializes communication over the USB serial port.
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* This must be called before any other usb function
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* may be used.
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**/
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void usb_init() {
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//Set baud rate
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// - 115200 (both wired and wireless) is UBRR=8, U2X=1
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// - 9600 is U2X =1, UBRR = 107.
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#if (USB_BAUD == 115200) |
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UBRR0H = 0x00;
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UBRR0L = 8;
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UCSR0A |= _BV(U2X0); |
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#elif (USB_BAUD == 9600) |
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UBRR0H = 0x00;
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UBRR0L = 103;
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UCSR0A |= _BV(U2X0); |
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#else //Baud rate is defined in the header file, we should not get here |
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return;
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#endif
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/*Enable receiver and transmitter */
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UCSR0B |= (1<<RXEN0)|(1<<TXEN0); |
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/* Set frame format: 8data, 1stop bit, asynchronous normal mode */
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UCSR0C |= (1<<UCSZ00) | (1<<UCSZ01); |
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// if we have enabled the stdio stuff, then we init it here
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#ifdef USE_STDIO
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/* Open the stdio stream corresponding to this port */
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usb_fd = fdevopen(usb_putc, usb_getc); |
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#endif
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} |
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/**
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* Initializes communication over the XBee.
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* This must be called before any other xbee function
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* may be used.
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**/
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void xbee_init() {
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//Set baud rate
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// - 115200 (both wired and wireless) is UBRR=8, U2X=1
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// - 9600 is U2X =1, UBRR = 107.
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#if (XBEE_BAUD == 115200) |
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UBRR1H = 0x00;
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UBRR1L = 8;
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UCSR1A |= _BV(U2X1); |
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#elif (XBEE_BAUD == 9600) |
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UBRR1H = 0x00;
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UBRR1L = 103;
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UCSR1A |= _BV(U2X1); |
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#else //Baud rate is defined in the header file, we should not get here |
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return;
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#endif
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//Enable receiver and transmitter
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UCSR1B |= (1<<RXEN1)|(1<<TXEN1); |
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// Set frame format: 8data, 1stop bit, asynchronous normal mode
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UCSR1C |= (1<<UCSZ10) | (1<<UCSZ11); |
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// if we have enabled the stdio stuff, then we init it here
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#ifdef USE_STDIO
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/* Open the stdio stream corresponding to this port */
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xbee_fd = fdevopen(xbee_putc, xbee_getc); |
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#endif
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} |
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/**
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* Sends a character over USB.
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*
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* @param c the character to send
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* @return 0 for success, nonzero for failure
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**/
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int usb_putc(char c) |
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{ |
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// Wait until buffer is clear for sending
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loop_until_bit_is_set(UCSR0A, UDRE0); |
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// Load buffer with your character
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UDR0 = c; |
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return 0; |
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} |
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/**
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* Sends a character to the XBee.
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*
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* @param c the character to send
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* @return 0 for success, nonzero for failure
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**/
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int xbee_putc(char c) |
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{ |
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// Wait until buffer is clear for sending
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loop_until_bit_is_set(UCSR1A, UDRE1); |
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// Load buffer with your character
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UDR1 = c; |
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return 0; |
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} |
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/**
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* Sends a sequence of characters over USB.
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*
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* @param s the string to send
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* @return 0 for success, nonzero for failure
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**/
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int usb_puts(char *s) |
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{ |
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char *t = s;
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while (*t != 0) |
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{ |
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usb_putc(*t); |
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t++; |
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} |
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return 0; |
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} |
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/**
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* Returns the first character in the buffer received from USB.
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* This function blocks execution until a character has been received.
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* xbee_init must be called before this function may be used.
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*
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* @return the first character in the usb buffer
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*
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* @see usb_init, usb_getc_nb
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**/
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int usb_getc(void) |
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{ |
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// Wait for the receive buffer to be filled
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loop_until_bit_is_set(UCSR0A, RXC0); |
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// Read the receive buffer
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return UDR0;
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} |
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/**
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* Returns the first character in the buffer received from USB.
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* This function blocks execution until a character has been
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* received. xbee_init must be called before this function
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* may be used.
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*
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* @return the first character in the xbee buffer
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*
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* @see xbee_init, xbee_getc_nb
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**/
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int xbee_getc(void) |
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{ |
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// Wait for the receive buffer to be filled
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loop_until_bit_is_set(UCSR1A, RXC1); |
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// Read the receive buffer
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return UDR1;
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} |
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/**
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* Non blocking version of usb_getc. If a character is present in the buffer,
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* it is returned, otherwise -1 is returned immediately. usb_init must be
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* called before this function can be used.
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*
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* @param c the received character. This will be set if a character has
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* been received.
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*
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* @return -1 if no character is available, 0 otherwise
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*
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* @see usb_init, usb_getc
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**/
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int usb_getc_nb(char *c) |
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{ |
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// check if the receive buffer is filled
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if (UCSR0A & _BV(RXC0)) {
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// Read the receive buffer
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(*c) = UDR0; |
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return 0; |
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} |
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else {
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// Return empty
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return -1; |
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} |
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} |
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/**
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* Non blocking version of xbee_getc. If a character is present in the buffer,
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* it is returned, otherwise -1 is returned immediately. xbee_init
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* must be called before this function can be used.
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*
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* @param c the received character. This will be set if a character has
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* been received.
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*
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* @return -1 if no character is available, 0 otherwise
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*
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* @see xbee_init, xbee_getc
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**/
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int xbee_getc_nb(char *c) |
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{ |
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// check if the receive buffer is filled
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if (UCSR1A & _BV(RXC1)) {
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// Read the receive buffer
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(*c) = UDR1; |
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return 0; |
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} |
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else {
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// Return empty
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return -1; |
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} |
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} |
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/*
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prints an int to serial
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code adapted from Chris Efstathiou's code (hendrix@otenet.gr)
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uses usb_putc
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*/
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/**
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* Prints an integer, converted to ASCII, to usb. usb_init must be called
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* before this function can be used.
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*
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* @param value the integer to print
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*
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* @return 0 if successful, nonzero otherwise
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*
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* @see usb_init, usb_putc
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**/
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int usb_puti(int value ) { |
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unsigned char usb_data[6]={'0','0','0','0','0','0' }, position=sizeof(usb_data), radix=10; |
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/* convert int to ascii */
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if(value<0) { usb_putc('-'); value=-value; } |
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do { position--; *(usb_data+position)=(value%radix)+'0'; value/=radix; } while(value); |
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/* start displaying the number */
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for(;position<=(sizeof(usb_data)-1);position++) |
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{ |
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usb_putc(usb_data[position]); |
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} |
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return 0; |
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} |
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