The document discusses how to configure timers on an Arduino to generate pulse-width modulated (PWM) signals for controlling servo motors. It explains that servo motors use PWM signals of varying pulse widths to control angular position precisely. It then provides code examples and explanations for setting up timer 1 on an Arduino in fast PWM mode at 50Hz to generate the necessary PWM signals, including setting the prescaler, waveform generation mode, and compare value. It also gives examples of PWM pulse widths needed to control a servo at different angles.

1. ROBO INDIA
http://roboindia.com

3. • Servo motor is nothing but a simple
motor based on servo mechanism.
• Servomechanism is a closed loop
feedback systems uses +ve feedback to
control its motion.
• With the help of servomechanism,
servo motor give precise control of
angular position.

4. • Motor have a dedicated encoder
• Simplest servomotors use position-only
sensing via a potentiometer
Click here to visit -ROBO INDIA

5. TCCR1A|=(1<<COM1A1)|(1<<COM1B1)|(1<<WGM11);
//NON Inverted PWM
TCCR1B|=(1<<WGM13)|(1<<WGM12)|(1<<CS11)|(1<<CS10);
//PRESCALER=64 MODE 14(FAST PWM)
ICR1=4999;
//fPWM=50Hz (Period = 20ms Standard).
DDRD|=(1<<PD4)|(1<<PD5);
//PWM Pins as Out
Click here to visit -ROBO INDIA

6. TCCR1A|=(1<<COM1A1)|(1<<COM1B1)|(1<<WGM11);
• COM1A1 = 1
• COM1B1 = 1
• WGM11 = 1
1 0 1 0 0 0 1 0
Click here to visit -ROBO INDIA

7. TCCR1A|=(1<<COM1A1)|(1<<COM1B1)|(1<<WGM11);
• WGM10 = 0 //Used in Waveform Generation
• WGM11 = 1 //Used in Waveform Generation
• COM1A1 = 1
• COM1B1 = 1
1 0 1 0 0 0 1 0
Click here to visit -ROBO INDIA

8. • The COM1A1,COM1A0,COM1B1 and
COM1B0 control OC1A and OC1B
1 0 1 0 0 0 1 0
Click here to visit -ROBO INDIA

9. TCCR1B|=(1<<WGM13)|(1<<WGM12)|(1<<CS11)|(1<<CS10);
• WGM12 = 1
• WGM13 = 1
• CS11 = 1
• CS10 = 1
0 0 0 1 1 0 1 1
Click here to visit -ROBO INDIA

10. TCCR1B|=(1<<WGM13)|(1<<WGM12)|(1<<CS11)|(1<<CS10);
• WGM10 = 0 // TCCR1A
• WGM11 = 1 // TCCR1A
• WGM12 = 1 // TCCR1B
• WGM13 = 1 // TCCR1B
0 0 0 1 1 0 1 1
Click here to visit -ROBO INDIA

11. • WGM10 = 0 // TCCR1A
• WGM11 = 1 // TCCR1A
• WGM12 = 1 // TCCR1B
• WGM13 = 1 // TCCR1B
Click here to visit -ROBO INDIA

12. • FAST PWM Mode
• TOP Value = ICR1
//Timer count from 0 to ICR1
Click here to visit -ROBO INDIA

13. TCCR1B|=(1<<WGM13)|(1<<WGM12)|(1<<CS11)|(1<<CS10);
CS12 = 1 : CS11 = 1 : CS10 = 0
0 0 0 1 1 0 1 1
Click here to visit -ROBO INDIA

14. TCCR1B|=(1<<WGM13)|(1<<WGM12)|(1<<CS11)|(1<<CS10);
• Prescaler is 64.
• Means16MHz/64 = 250khz (4 uS period)
0 0 0 1 1 0 1 1
Click here to visit -ROBO INDIA

15. 𝑓 𝑝𝑤𝑚 =
𝑓 𝑐𝑝𝑢
𝑛(1 + 𝑇𝑂𝑃)
Click here to visit -ROBO INDIA

16. 𝑓 𝑝𝑤𝑚 =
𝑓 𝑐𝑝𝑢
𝑛(1 + 𝑇𝑂𝑃)
fpwm = 20ms (50 Hz)
fcpu = 16000000Hz
n = 64
TOP = 4999 // RESULT
Click here to visit -ROBO INDIA

17. 𝑓 𝑝𝑤𝑚 =
𝑓 𝑐𝑝𝑢
𝑛(1 + 𝑇𝑂𝑃)
fpwm = 20ms (50 Hz)
fcpu = 16000000Hz
n = 64
TOP = 4999 // RESULT
Click here to visit -ROBO INDIA

18. 𝑓 𝑝𝑤𝑚 =
𝑓 𝑐𝑝𝑢
𝑛(1 + 𝑇𝑂𝑃)
fpwm = 20ms (50 Hz)
fcpu = 16000000Hz
n = 64
TOP = 4999 // RESULT
Click here to visit -ROBO INDIA

19. 𝑓 𝑝𝑤𝑚 =
𝑓 𝑐𝑝𝑢
𝑛(1 + 𝑇𝑂𝑃)
fpwm = 20ms (50 Hz)
fcpu = 16000000Hz
n = 64
TOP = 4999 // RESULT
Click here to visit -ROBO INDIA

20. TCCR1A|=(1<<COM1A1)|(1<<COM1B1)|(1<<WGM11);
//NON Inverted PWM
TCCR1B|=(1<<WGM13)|(1<<WGM12)|(1<<CS11)|(1<<CS10);
//PRESCALER=64 MODE 14(FAST PWM)
ICR1=4999;
//fPWM=50Hz (Period = 20ms Standard).
DDRD|=(1<<PD4)|(1<<PD5);
//PWM Pins as Out
Click here to visit -ROBO INDIA

21. • Servo Angle 0 need 0.388ms(388uS) pulse
Value of OCR1A = 388us/4us = 97
• Servo Angle 90 need 1.264ms(1264uS) pulse
Value of OCR1A = 1264us/4us = 316
• Servo Angle 180 need 2.140ms(2140uS) pulse
Value of OCR1A = 2140us/4us = 535
Click here to visit -ROBO INDIA

22. To share your views and queries please write us-
Website: http://roboindia.com
Email- info@roboindia.com
Click here to visit -ROBO INDIA