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--- en:examples:motors:dc [2009/03/26 17:49] – raivo.sell
+++ en:examples:motors:dc [2010/02/04 14:29] (current) – removed mikk.leini
@@ Line 1: / Line 1: @@
-===== DC Motors =====
-The operation of direct current (DC) motors, like all other electric motors, is based on
-simple electromagnetism. Brushed DC motors have two wire connectors, positive and
-negative. The rotation direction is determined by the polarity and speed by the
-voltage.
-Controlling the DC motor:
-One full H-bridge or two half bridges (push–pull drivers) can be used for driving one
-DC motor forwards and backwards. Drive circuits are available as ASICs, or can be
-built from separate components, such as transistors. In this lab we are using the IC
-L293D, which contains four push–pull drivers in one chip package.
-===== Simple test program. =====
-With this compied program you can test your equipment set-up.
-DC motor is connected to DC1 port 2 and servo motor PWM1
-{{:et:failid:mootorite_testv5.hex|}}
-===== Connection schema =====
-{{:examples:actuator:dc_schema.jpg?500|}}
-Motor drive signals from ATmega128 to the actuator board
-{{:examples:actuator:dc_connection_table.jpg|}}
-===== Connecting the components =====
-Electrical connections
-  - Make sure all power is off.
-  - Connect the actuator board and main board with a 26-pin cable.
-  - Connect the DC motor(s) to the actuator board, as shown in Figure 1.
-  - Connect the JTAG converter with the ATmega128 main board and the PC.
-  - Finally, connect the power to the main and actuator boards.
-{{:examples:dc_servo_cpu.jpg?500|}}
-{{:examples:dc_servo_cpu_connection.jpg?500|}}
-===== Example code =====
-<code c>
-/*-------------------------------------------------------------
-Title: DC motor with Actuator Board
-Date: 080424
-Ver.: 1.2
-Compiler: AVR-GCC
-Target: ATmega128
-Hardware: ATmega128 controller board, Actuator board, DC motor
-Author: Raivo Sell 2008
-Notes: in1 PD7 in2 PD6
-Optimization: -O0 (needed for delay function)
-Description: Start and stop the DC motor and change the rotation direction.
-Motor is connected to the DC1 pins 3
----------------------------------------------------------------*/
-#define SET(x) |= (1<<x) //set bit high bit in pin x
-#define CLR(x) &=~(1<<x) //set bit low bit in pin x
-#define MS (100) //defines delay
-#define F_CPU 14745600UL //CPU Frequency (influences delay function)
-#include <avr/io.h>
-///////////////// Functions //////////////////////////////////
-void dc_drive(int pin, int op){ // DC motor control function
-	if (op==1) PORTD SET(pin);
-	else PORTD CLR(pin);
-}
-void _delay_ms(int t){ // Delay function
-	int i,j;
-	for (i=0;i<t;i++){
-		for (j=0;j<8000;j++){}
-	}
-}
-///////////////// Main function //////////////////////////////////
-int main (void){
-	DDRD = 0xFF;// set port direction (output)
-	PORTD = 0x00;// initialize port
-	while(1){
-		dc_drive(6,1); // Start DC motor
-		dc_drive(7,0);
-		_delay_ms(MS); // Wait for a second
-		dc_drive(6,0); // Change direction
-		dc_drive(7,1);
-		_delay_ms(MS); // Wait for a second
-		dc_drive(6,0); // Stop DC motor
-		dc_drive(7,0);
-		_delay_ms(MS); // Wait for a second
-	}
-}
-</code>

en/examples/motors/dc.1238082597.txt.gz · Last modified: 2020/07/20 12:00 (external edit)