Pulse Width Modulation and Servo Motors

 


From https://en.wikipedia.org/wiki/Servo_control#/media/File:Servomotor_Timing_Diagram.svg

Now for a cycle of 50 Hz this means.....

1.5ms = 20ms  * x/100(where x is the duty cycle) 

x = 7.5% duty cycle for 0 position

For 90 degree position

2ms = 20ms * x/100

x = 10% duty cycle

For -90 degree position

1ms = 20ms * x/100

x = 5%





Comments

Post a Comment

Popular posts from this blog

Week 4

 Making a buzzer sound Discuss max current draws on the Raspberry Pi. V = IR For GPIO pins this means  3.3 = 0.016 R R= 3.3/0.016 R= 206.25 Ohms Therefore the lowest resistance we can have in a output circuit is 206.25 Ohms How to use the debugger to examine buzzer code. Using the "time" calls and turning the output pin on and off make the buzzer sound The buzzer sound is too low just using the GPIO pin so we need one of two things A transistor to amplify the signal from the GPIO pin without increasing the current draw on the GPIO pin A passive buzzer board that has a power and signal input. Extension activity making the buzzer sound using PWM What are the limits of changing the frequency.  Possible reasons why. Programming today Finish of variables from last week. Looping For, While Add up numbers 1-100 Using for loop Functions (intro)  Scope of blocks (counter inside function) use of the global keyword. Homework Using a while loop add Fibonacci numbers and output...
Read more

Github and code

Image
Setting up your computer to interact with GitHub  Get the Code (using git on the command line)  in Linux and Mac Prepare a folder where you want to put the code. mkdir <directory> Change the permissions to allow you to read write and execute on that directory. chmod ugo=rxw <directory>   Clone the repository from github (requires pi connected to the net) git clone https://github.com/woodno/raspberry.git Whenever you want to update your code use... git pull Get the Code  (using git on the command line)  in Windows Find out if you have git installed by opening a console and typing  git --version If this works you have git installed.  If not follow step 2 You may need to install git for windows. https://gitforwindows.org/ Go to a directory you have created ready to hold your python code. Download the code with... git clone https://github.com/woodno/raspberry.git Whenever you want to update your code use... git pull Using s...
Read more

Week 1

 Activities. Tell us about yourself.  Why are you here?  Are you just keen to learn anything or are you here to get the skills to do a project.  If so what is the project.  What are your previous experiences with programming and electronics. Noel will tell you about himself. Connect Laptop to Pi (Almost everyone has done these steps)   Raspberry Pi has a new tool called Raspberry Pi connect. Allow Raspberry Pi Connect on install or from config Get a Raspberry Pi Id (on the client browser) Get a verification code on the console rpi-connect signin That should return https://connect.raspberrypi.com/verify/XXXX-XXXX Visit that on the client browser Uniquely name the connection Sign in Details at  https://www.raspberrypi.com/documentation/services/connect.html Config Pi to allow SPI Download code for course from github using git. Practice some useful linux commands Find out which directory you are in. pwd list things in the directory ls telling directorie...
Read more