technotes.tick

Pull up and pull up resistors are two common terms that we could hear in the case of the electronics circuits.I have also tried to hear these concepts from  different people and will think at the moment that it has been well understood.Then when the next time I hear about it the concept would have long gone.So I was searching something that visually communicate it with least amount of  tech talk.And the following video from the Human Hard drive guy matched the profile.The guy has explained in a simple manner even to the depth that he actually explained what is meant by when we write 'Uc' which is a small and understood detail but an important point for a newbie.Thanks for the video and anyone looking into these concept could find this video helpful.                        Do remember the points : Pull down resistor requires 10 times impedance of the internal resistance of the microcontroller. Pull down resistors are also not inverting(Which as expected open means O

From What I Understand the rotary encoders are the same as the quadrature encoder.So the following writing I did is for understanding such a system. Following helped me in understanding the rotary encoder,                  The below site has good visuals and writing about the type of encoders: http://www.anaheimautomation.com/manuals/forms/encoder-guide.php#sthash.YJMaBtVs.dpbs So points that I feel must be remembered while doing so are(These where obtained from a PDF material I got from Internet regarding the various encoders  as I have no experience with these - So if the owner of the content wants me remove these please ask me so and I will be happy to do it), Rotary encoders, also called rotary shaft encoders or rotary shaft-angle encoders. They provide rate and positioning information in servo feedback loops.  A rotary encoder can sense a number of discrete positions per revolution. The number is called points per revolution (Analogous to the steps per revol

Links to site with data for motor driving AVR based microcontroller http://www.robotplatform.com/howto/dev_board/atmega8_dev_board_1.html Motor driver using the L293 IC http://www.robotplatform.com/howto/L293/motor_driver_1.html                                                                                                                                                                                                                                                                                                                                  ]                                                                                                                                                                            

Important from the AVR freaks http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&p=1030267 If I have to remove these contents against copyright please do leave a comment,I will remove it. All I wanted with this post was to accumulate all these to this page as I will not loose time pondering the internet for these data. Following are some extracts from the comment section of the AVR freaks : For a simple servo control we have to:  Read the actual position  Compare with demanded position  Compute the error  Add some deadband  Tell motor to go fwd,rev or stop  The longest part would be reading the adc, i would guess a total of 200us for each servo  For the linear actuators,  Get current position  Compare with wanted position  Tell motor to go fwd,rev or stop  Encoder fires an external interrupt. Isr updates the current position and stops the motor when it hits the wanted position.  Flat stick the isr will suck 3% of cpu.  Mainline code will tak