/*,-----------------------------------------------------------------------------------------.| io/servo|-----------------------------------------------------------------------------------------| this file implements functions to control a rc-car servo motor|| Author   : {{removed according to contest rules}}|            -> circuitcellar.com avr design contest 2006|            -> Entry #AT2616||-----------------------------------------------------------------------------------------| License:| This program is free software; you can redistribute it and/or modify it under| the terms of the GNU General Public License as published by the Free Software| Foundation; either version 2 of the License, or (at your option) any later| version.| This program is distributed in the hope that it will be useful, but|| WITHOUT ANY WARRANTY;|| without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR| PURPOSE. See the GNU General Public License for more details.|| You should have received a copy of the GNU General Public License along with| this program; if not, write to the Free Software Foundation, Inc., 51| Franklin St, Fifth Floor, Boston, MA 02110, USA|| http://www.gnu.de/gpl-ger.html`-----------------------------------------------------------------------------------------*/#include "servo.h"#include "debug.h"#include <avr/delay.h>unsigned char servo_pos;#define SERVO_BMP_HEADER_LENGTH 62//bmp data must be a multiple of 16 ?! -> maybe add padding !#define SERVO_BMP_WIDTH 256//256 pixel -> 256/8 = 32 ! must be divided by 4 -> ok!#define SERVO_BMP_LINE_WIDTH 256#define SERVO_BMP_HEIGHT 1#define SERVO_BMP_FILESIZE (SERVO_BMP_LINE_WIDTH/8)*(SERVO_BMP_HEIGHT)+62PROGMEM unsigned char SERVO_BMP_HEAD [] = {0x42, 0x4D, 0x5E, 0x13, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, //100x3E, 0x00, 0x00, 0x00, //first image data at pos 0x3E -> at byte 620x28, 0x00, 0x00, 0x00, //header size (infoheader only!!) -> 40 byteslo8(SERVO_BMP_WIDTH), hi8(SERVO_BMP_WIDTH), 0x00, 0x00, //width <lo,hi,0,0>lo8(SERVO_BMP_HEIGHT), hi8(SERVO_BMP_HEIGHT), 0x00, 0x00, //height <lo,hi,0,0>0x01, 0x00, //1color plane0x01, 0x00, //1bit0x00, 0x00, 0x00, 0x00, //no compressionlo8(SERVO_BMP_FILESIZE), hi8(SERVO_BMP_FILESIZE), 0x00, 0x00, //imagesize in bytes0x10, 0x0B, 0x00, 0x00, //x pixels per meter0x10, 0x0B, 0x00, 0x00, //y pixels per meter0x02, 0x00, 0x00, 0x00, //2 colors (B/W)0x02, 0x00, 0x00, 0x00, //2 important colors0xFF, //background B0xFF, //background G0xFF, //background R0x00,0xC0, //foreground B0xC0, //foreground G0xC0, //foreground R0x00 //62};void servo_init(){	//set up fast pwm mode:	#define WGM_CFG (1<<WGM00 | 1<<WGM01) //fast pwm	#define COM_CFG (1<<COM01 | 0<<COM00) //clr on match, set on max	#define CLK_CFG (0<<CS00 | 1<<CS01 | 1<<CS02) //set up clock source	TCCR2 = WGM_CFG | COM_CFG | CLK_CFG;	//set pin as output	SERVO_DDR |= (1<<SERVO_PIN);	//initialise	servo_set_pos(127);}void servo_set_pos(unsigned char val){	#define CALC_1MS F_CPU/256/1000 //=28.8	servo_pos = val;	OCR2 = (CALC_1MS - 5 + (unsigned char)(((unsigned int)servo_pos*CALC_1MS)/255));}unsigned int servo_generate_bmp(unsigned char *buffer, unsigned int datapos, unsigned int len, unsigned int streampos, unsigned char source){	unsigned char out;	unsigned int x;	//step1: send bmp header (if requested)	PGM_P header_ptr = SERVO_BMP_HEAD;	for(x=streampos; x<SERVO_BMP_HEADER_LENGTH; x++){		buffer[datapos++] = pgm_read_byte(header_ptr++);		streampos++;		len--;		//no more data allowed		if (len == 0)			return 0;	}	//step2 generate plot:	//calculate position: streampos must be > PLOT_BMP_HEADER_LEN now...	streampos -= SERVO_BMP_HEADER_LENGTH;	//now show image:	out = 0;	unsigned char spos = servo_pos;	for(unsigned char i=streampos; i<256/8; i++){		for(unsigned char b=0; b<8; b++){			out = out << 1;			if (i*8+b < spos){				out |= 1;			}		}		buffer[datapos++] = out;		len--;		//streampos++;		if (len == 0)			return 0;	}	return datapos;}