00001 /*! \file servo.h \brief Interrupt-driven RC Servo function library. */ 00002 //***************************************************************************** 00003 // 00004 // File Name : 'servo.h' 00005 // Title : Interrupt-driven RC Servo function library 00006 // Author : Pascal Stang - Copyright (C) 2002 00007 // Created : 7/31/2002 00008 // Revised : 8/02/2002 00009 // Version : 1.0 00010 // Target MCU : Atmel AVR Series 00011 // Editor Tabs : 4 00012 // 00013 /// \ingroup driver_sw 00014 /// \defgroup servo Interrupt-driven RC Servo Function Library (servo.c) 00015 /// \code #include "servo.h" \endcode 00016 /// \par Overview 00017 /// This code allows you to drive up to 8 RC servos from any 00018 /// combination of ports and pins on the AVR processor. Using interrupts, 00019 /// this code continuously sends control signals to the servo to maintain 00020 /// position even while your code is doing other work. 00021 /// 00022 /// The servoInit and servoOff effectively turn on and turn off servo 00023 /// control. When you run ServoInit, it automatically assigns each 00024 /// "channel" of servo control to be output on the SERVO_DEFAULT_PORT. 00025 /// One "channel" of servo control can control one servo and must be 00026 /// assigned single I/O pin for output. 00027 /// 00028 /// If you're using all eight channels (SERVO_NUM_CHANNELS = 8), then 00029 /// then by default the code will use SERVO_DEFAULT_PORT pins 0-7. 00030 /// If you're only using four channels, then pins 0-3 will be used by 00031 /// default. 00032 /// 00033 /// The command servoSetChannelIO(channel, port, pin) allows you to 00034 /// reassign the output of any channel to any port and I/O pin you 00035 /// choose. For exampe, if you have an RC servo connected to PORTC, pin 6, 00036 /// and you wish to use channel 2 to control it, use: 00037 /// 00038 /// servoSerChannelIO( 2, _SFR_IO_ADDR(PORTC), 6) 00039 /// 00040 /// (NOTE: you must include the "_SRF_IO_ADDR()" part around your port) 00041 /// 00042 /// The servoSetPostion and servoGetPosition commands allow you to command 00043 /// a given servo to your desired position. The position you request must 00044 /// lie between the SERVO_MIN and SERVO_MAX limit you defined. 00045 /// 00046 /// \WARNING: This servo library has been tested to work without issue on 00047 /// several different AVR processors and with several different brands/kinds 00048 /// of servos. However: 00049 /// - Proper output duty cylces are dependent upon a user calibation and 00050 /// configuration. 00051 /// - IF YOUR SERVOS ARE EXCEPTIONALLY POWERFUL, AN ERRONEOUS OUTPUT DUTY 00052 /// CYCLE GENERATED FROM THIS CODE OR ANY OTHER SOURCE CAN DAMAGE YOUR 00053 /// SERVO'S INTERNAL DRIVER CHIP OR ITS GEARS! 00054 /// - I have never experienced any servo damage from erroneous control signal 00055 /// input, but it is possible. 00056 // 00057 // This code is distributed under the GNU Public License 00058 // which can be found at http://www.gnu.org/licenses/gpl.txt 00059 // 00060 //***************************************************************************** 00061 00062 #ifndef SERVO_H 00063 #define SERVO_H 00064 00065 #include "global.h" 00066 #include "timer.h" 00067 00068 // include configuration 00069 #include "servoconf.h" 00070 00071 typedef struct struct_ServoChannel 00072 { 00073 // hardware I/O port and pin for this channel 00074 u08 port; 00075 u08 pin; 00076 // PWM duty setting which corresponds to servo position 00077 u16 duty; 00078 } ServoChannelType; 00079 00080 // functions 00081 00082 // initializes servo system 00083 // You must run this to begin servo control 00084 void servoInit(void); 00085 00086 // turns off servo system 00087 // This stops controlling the servos and 00088 // returns control of the SERVOPORT to your code 00089 void servoOff(void); 00090 00091 // set the port and I/O pin you wish to use for a given channel 00092 // If you do not assign a port and I/O pin for a channel (ie. you don't 00093 // use this command) then all output will be done through the 00094 // SERVO_DEFAULT_PORT. See above definition of SERVO_DEFAULT_PORT. 00095 void servoSetChannelIO(u08 channel, u08 port, u08 pin); 00096 00097 // set and get servo position on a given channel 00098 // servoSetPosition() commands the servo on <channel> to the position you 00099 // desire. The position input must lie between 0 and POSITION_MAX and 00100 // will be automatically scaled to raw positions between SERVO_MIN and 00101 // SERVO_MAX 00102 // servoGetPosition() returns the most recently set postition of the 00103 // servo on <channel>. The return value will be scaled 0->POSITION_MAX 00104 void servoSetPosition(u08 channel, u08 position); 00105 u08 servoGetPosition(u08 channel); 00106 00107 // set and get raw servo position on a given channel 00108 // Works like non-raw commands but position is not scaled. Position must 00109 // be between SERVO_MIN and SERVO_MAX 00110 void servoSetPositionRaw(u08 channel, u16 position); 00111 u16 servoGetPositionRaw(u08 channel); 00112 00113 // servo interrupt service routine 00114 void servoService(void); 00115 00116 #endif