Its locomotion is controlled by two DC motors one on each side with their speed reduced by gear boxes. I will not discuss the detail of the mechanical and the electronic part of the car and of course the video display part of the software on a PC here.
So, inputs and output modules of the car are just represented as blocks. Here is the sketch I have drawn using the Google SketchUp. As I tried to show in the diagram above, there are two main parts of the project: PC and the car. I made the RF link a one way communication because the RF components I found support this mode of operation.
These are circuits used for avoiding collision with obstacles. This is done with a simple logic described in the table below. You may refer here about building a simple IR sensor circuit.
The next thing is an RF receiver. Commands are constantly transmitted from the RF transmitter connected to the serial port of a PC as a form of series of bits and received by the RF receiver located on the car. I have created a simple C application for command bits generation and for video display and replay functionalities. The RF transmitter accepts these data from the serial port and transmits them through its antenna with a proper modulation.
The transmitter and receiver data sheets with their application can be found here and here. These two H-bridges are driven by outputs of micro-controller through one of parallel port pins.
A very good introduction and application about H-bridges can be found here. The video display and replay module uses DirectShow libraries to access video data from wireless video receiver but since this software part is not my concern, I am not discussing it right now. As a reference, you may check a really nice article by Andrew Krillov on codeProject here.
The car control module is implemented using a SerialPort object, seven buttons for direction control and a combo box for listing available serial ports.
Just remember to include the following namespace:. On each button click, a SendToSerialPort string data method is called with its respective string parameter as explained below:. The motor drivers H-bridges are connected to the micro controller's Port1 and are arranged as follows:. The direction control is realized by controlling both DC motors' directions. For example, to turn right, we drive the left motor forward and stop the right motor. And the individual motor direction is controlled by switching the four transistors ON and OFF which is represented by the byte values in the braces.
Code Review Stack Exchange is a question and answer site for peer programmer code reviews. It only takes a minute to sign up. The project I've been working on for my university requires me to write code to do the following:. If the ultrasonic sensor detects a distance within a certain range, output HIGH to activate an electric motor. I hope to create an array that will average the readings from the ultrasonic sensor over a. I started with a rangefinder script that went along with a tutorial provided on Arduino's website, so my goal is to modify that script to fit into my goals to output HIGH or LOW based on the code that I've tested and already works well to test for distance.
I am looking for any tips to create an array to average the distance from the sensor, then using a for loop to test whether it is in the interval and output HIGH or LOW. Your constants, global variable, and functions should start with a lowercase letter. Since your constants are similar, you can group them into an enum instead:. This could also help with code maintenance.
If you ever need to add another Pinyou just need to insert it into the enum appropriately, as opposed to creating another constant. Duration is only used in loopso just initialize and use it there. Having it as a global variable could invite bugs, and is otherwise bad practice.
This applies to global variables in general because they're accessible throughout the entire program, meaning they can be changed anywhere.
You're using "magic numbers" hard-coded numbers in places. You should either make them variables or constants, or provide comments to specify their meaning.
Your indentation is quite inconsistent. You indent a different number of spaces in different functions, but you should stick to one most common is four spaces. You especially should have indentation within functions, otherwise it may appear that the code isn't contained within that function. There shouldn't be a semicolon after the if condition, otherwise the following statements won't work with it.
I try to rotate a full rotation servo motor using the Arduino Pro kit. I use Write in order to control the speed and the direction of the servo motor using this function. Now I want to know the unit of this parameter, because when I set this parameter to 45 the speed is higher than when I set it to 90! How can I fix this problem? On a continuous rotation servo, this will set the speed of the servo with 0 being full-speed in one direction, being full speed in the other, and a value near 90 being no movement.
I have some code example for controlling servo motors from class library, i hope you can get a little help form it. You can uses a axis card to control servo easily. It provides the better accuracy for pulse and direction controlling. Learn more. Ask Question. Asked 7 years ago.
Active 6 years, 3 months ago. Viewed 4k times. Peter Mortensen Wazani Wazani 1 1 gold badge 12 12 silver badges 27 27 bronze badges. Active Oldest Votes.In this chapter, we will interface different types of motors with the Arduino board UNO and show you how to connect the motor and drive it from your board. A DC motor Direct Current motor is the most common type of motor. DC motors normally have just two leads, one positive and one negative. If you connect these two leads directly to a battery, the motor will rotate.
If you switch the leads, the motor will rotate in the opposite direction. This may damage the board. Use a driver Circuit or an IC. First, make sure that the transistor is connected in the right way.
The flat side of the transistor should face the Arduino board as shown in the arrangement. The transistor acts like a switch, controlling the power to the motor. Arduino pin 3 is used to turn the transistor on and off and is given the name 'motorPin' in the sketch.
The transistor acts like a switch, controlling the power of the motor. When the program starts, it prompts you to give the values to control the speed of the motor. You need to enter a value between 0 and in the Serial Monitor.
In the 'loop' function, the command 'Serial. You can type any number here. The 'if' statement in the next line simply does an analog write with this number, if the number is between 0 and The DC motor will spin with different speeds according to the value 0 to received via the serial port. To control the direction of the spin of DC motor, without interchanging the leads, you can use a circuit called an H-Bridge.
An H-bridge is an electronic circuit that can drive the motor in both directions. H-bridges are used in many different applications.
One of the most common application is to control motors in robots. It is called an H-bridge because it uses four transistors connected in such a way that the schematic diagram looks like an "H.
The L can control the speed and direction of DC motors and stepper motors, and can control two motors simultaneously. Its current rating is 2A for each motor. At these currents, however, you will need to use heat sinks. The above diagram shows how to connect the L IC to control two motors. Pins 5 and 7 are digital, i.Hello everyone! In this project we will be controlling the direction of a motor using two ultrasonic ranging sensors.
If both of the sensors or none of the sensors are triggered at the same time, the motor will not spin. Everything from my last Instructable which includes:. Two 9v Battery.
Arduino - DC Motor
A Motor. One 5v relay switch module. Two Ultrasonic range sensor. One Breadboard or protoshield with breadboard. Did you use this instructable in your classroom? Add a Teacher Note to share how you incorporated it into your lesson. I used staple clips instead of jumper wires for optimized cable management. This is completely optional and you can use jumper wires as an alternative. This was covered in the previous Instructable where we connected the 9v battery to the DC motor.
In this project, we will be using the left and right sensors to control the direction of the motor. Unlike the previous Instructable, IN 1 is connected to digital pin 7 while IN 2 is still connected to digital pin Here is the link to the code.
Don't forget to include the New ping library. This allows you to communicate with multiple ultrasonic sensors easily. If everything was done correctly, the rotation of the motor will be controlled by the objects that trigger the ultrasonic sensors.
I'm wanting to make a circuit whereby a motor is controlled using a proximity sensor. The closer an object gets to the sensor, the further to the right the motor turns, as the object moves further away, the motor graduates to the left. Any chance you could help me to work out how to do that? More by the author:. About: Youtube: www. If the right sensor is triggered, the motor will spin counter-clockwise.
If the left sensor is triggered, the motor will spin clockwise. If both of the sensors or none of the sensors are triggered at the same time, the motor will not spin This simple project is helpful if you want to build a car that is capable of avoiding obstacles.
The components that were used in this project are: Everything from my last Instructable which includes: Two 9v Battery countless M-F jumper wires A Motor One 5v relay switch module and Add Teacher Note.
Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. I had attahched the device through USB to a Windows machine previously and used Trinamic's proprietary software to test if the controller is functional as expected, and it seems to be.
The beginner's manual of the StepRocker mentions certain commands that should be sent over the serial interface to rotate the motor left, right, or bring it to a halt. The console application which I plan to write should be non-blocking. Here is an image of the datagrams being sent and response received while a rotate command is issued:.
I tried to write a simple program to feed the rotation value datagram shown in the picture to the motor controller:. But this does not alter the LED behaviour of the controller in any way and does not move the motor, of course.
Learn more. Asked 7 years, 3 months ago. Active 3 years, 3 months ago. Viewed 4k times. Subhamoy S. Doesn't it just appear as a virtual serial port when you connect it via USB? Active Oldest Votes. Thank you! I do not have any experience in this area. Pointing me to an example or something like that would be greatly appreciated. My distro is Ubuntu. Jan 11 '13 at I've write something about it in my LJ only russian.
I have added some more details of the problem. I can see the datagram being sent and getting received. BTW datagram simply decoded. Violet Giraffe Violet Giraffe 26k 32 32 gold badges silver badges bronze badges.
Could you please point me to some examples?Months ago I wrote a post on the use of motor encoders with Arduino and promised to follow up with a post on speed control. Then I started school I had no time for Colin or this blog for nine months. I structured my program to mirror the hardware as closely as possible so I made two classes, Motor and Encoder, to handle the low level functions of the motor and encoder.
PositionControl uses an instance of SpeedControl to provide position control functions and DifferentialDrive uses two instances of PositionControl to provide high level control for a differential drive robot like Colin. In my earlier post on motor control I explained that simply using analogWrite does not actually set the speed of a motor. It only sets the voltage to the motor. Varying loads will cause a motor to run at different speeds with the same input voltage.
This sounds like a job for a closed-loop controller! In a closed-loop controller, we tell the controller how fast we want the motor to run. We call this the set point. The controller then measures the actual speed of the motor and calculates the difference between the actual speed and the set point.
The controller then adjusts the voltage to the motor to reduce the error. This sounds simple enough, but how much should the controller adjust for a given error?
The adjustment would be defined as. If is very large the motor speed will oscillate around the set point and never stabilize.
If is small enough to avoid overshooting, however, the controller will respond very slowly to disturbances.
To compensate for this we can add a couple more terms to the adjustment equation. It will also make the controller faster to reach the set point. However, if the integral term is too large it will cause overshoot and oscillation. The integral term is defined as. A term calculated from the derivative of past errors helps to minimize overshoot and improve the stability of the controller. The derivative term is defined as. Every time the controller adjusts the voltage output to the motor it must find the current speed of the motor, calculate the error between the current speed and the set point, then use the above equation to determine how much the output voltage to the motor should be adjusted to compensate for the error.
It calculates the required adjustment to the PWM output to the Motor to maintain consistent speed. I would encourage you to check out his blog for a more in-depth explanation of PID control. Thanks for your work, Brett! The code above basically performs the calculation discussed in the preceding section.
In line 7 it fetches the current speed of the motor and calculates the error in line 9. It then calculates the proportional, integral, and derivative terms and uses them to calculate the adjustment in lines 10 through What gives? Basically, when the user changes the set point there is an instantaneous change in the error. This means the derivative of the error is infinite at this point.
Example Stepper Motor Control Programs
So in theory the derivative term becomes infinite whenever the set point changes, a phenomenon called derivative kick. Because the code above calculates the approximate numerical derivative the phenomenon is not as pronounced, but it should still be addressed. Making the change above corrects for derivative kick.
So how do we actually implement this to control a motor? The example sketch below demonstrates the use of my SpeedControl class, available on github.