This part price in offer to student that involve with ROVER project.
1 . DC gear motor ( 2 unit ) = RM140 ( including shipping fees)
- Output Power: 3.4 Watt
- Rated Speed: 170RPM
- Rated Current: 0.9A
- Rated Torque: 196mN.m
2 . L298 h-bridge (1 unit = RM28.00) ( including shipping fees)
3 . ULN2803 + IC socket (1 unit = RM10.00) ( including shipping fees)
4 . SPDT relay (1 unit =RM5.00) (includes shipping fees)
5 . Transistor 2N2222 (Metal Can) (1 unit=RM4.00) (includes shipping fees)
6 . PS2 connector (1 unit=RM8.00) (includes shipping fees)
7 . Servo motor (1 unit =RM55.00) ( includes shipping fees)
8 .Servo bracket (1 unit =RM22.00) ( includes shipping fees)
Now on to finding the set point, place your bot on the dead center of the line. The position or the third column of the readings above will give you your ‘set point’. Note it down separately.
If you have time,verify the set point before your final run, more on this will come up in the tuning section.
Now we’ll build the complete PID algorithm. Continue reading
The algorithm is the one thing that determines the performance of a line following robot more than anything else. The most basic algorithm , is the one which uses only one sensor. The sensor is placed in a position that is a little off centered to one of the sides, say right. When the sensor detects no line the robot moves to the left and when the sensor detects the line the robot moves to the right. A robot with this algorithm would follow the line like shown in the picture below
The PID algorithm uses three constants, Kp, Ki and Kd to function. They are shorthand notations for proportionality, integral and differential constants respectively. These three constants have to be set by you after testing, and define how good your control works.
Now let’s look at how to develop a simple PID control algorithm.
Use the Arduino function analogRead() to retrieve sensor values. You’ll need an array to store these variables. Use Serial.print() to display these sensor values and observe them through the serial monitor in the Arduino IDE. If you’re using five sensors connected at analog pins 0-4, your code would look somewhat like this; Continue reading
Only with 2 relay, i can drives 1 motor. This is not h-bridge connection. Thankx to mr chin for the idea.
A ULN2803 is an Integrated Circuit (IC) chip with a High Voltage/High Current Darlington Transistor Array. It allows you to interface TTL signals with higher voltage/current loads. In English, the chip takes low level signals (TLL, CMOS, PMOS, NMOS – which operate at low voltages and low currents) and acts as a relay of sorts itself, switching on or off a higher level signal on the opposite side.
H-Bridge IC gives a continuos 0 volt(as 0) or continuous 3 volt(as 1).
For controlling a motor in both direction, we can use L293D IC which simple to connect and we can controll two motor with the help of one IC, and the maximum current it can provide to motor is 1A. So if we are using motor controlling in a small robot or something else where no much load and motor can be drive by only 1A current then it is the best IC.