If you’re into robotics then you must know about the sumo competitions between autonomous robots. Seeker II is one of the competitors who proved his good design in battle. In this project you will have all the information you need to build yourself a mini-sumo robot.
The Seeker II is using a PIC16F876 providing four analog to digital converters for sensors, timing functions, a PWM output to control the motors and also allows for future calibration, testing and debugging. The robot is equipped with two range finding sensor from Sharp, GP2D12, placed right at the front and connected to analog inputs A0 and A1 of the PIC. Other two Fairchild QRD1114 sensor are placed at the bottom and used as edge finders and are connected to analog inputs A2 and A3.
The robot comes with two wide wheels which offers a good amount of traction, each wheel having its own motor. The motors, Faulhaber 1717, are driven by a SN754410 h-bridge IC controlled by the PIC. If the EN input is set high than Y output of the h-bridge will be same as the A input, if EN is set low then the Y output is turned off on the SN754410. The PIC controls the speed of the motors with PWM.
Ports C7 and C6 are used for serial communication, to watch, test and debug software, as well as to read log files from EEPROM.
In the link you will find block diagram, schematics and code for microcontroller.
Here is a good project for those who want to start with robotics. Fairly simple and if you are using a breadboard there is no soldering involved. It is a vehicle that follows a light source using two LDRs, two servo motors, two wheels and an Arduino as its brain. The two LDRs are placed one on the left and one on the right side of the vehicle and each one controls the motor from the opposite side.
Although this project can be done using discrete components alone, using an Arduino allows you to further develop the project. Light is detected by the two LDRs. Each LDR is connected in series with a resistor between Vcc and ground forming a voltage divider. The joint point between the LDR and the resistor is connected to one of the Arduino’s analog inputs.
You will need to play a little bit with the values of the resistor so that you get the right sensitivity for light detection. A variable resistor could be very handy. The motors who spin the wheels are two hacked servo motors. Since servo motors don’t spin 360 degrees there is a way explained in the project to transform them into gear motors.
Servo motors are however pretty easy to control with the microcontroller. You have a center value which will make the motor stand still and if you add or subtract from that value it will make it go forward or reverse. You will need to run a few tests to determine these values and to adjust the light sensors.
“Bilbo, look out for the Dragon!” cried Frodo. “Dragon? Nonsense! There hasn’t been a Dragon around here for a thousand years!” said Bilbo… but little did he know what some people are building in their dungeons. Presenting “Puff” the fire fighter Dragon. I bet Smokey the Bear will lose his job soon, as forest fire prevention mascot.
The Dragon, once it finds a fire, has it’s eyes fixed on it, closes in and puts the fire away with his breath. He he I know what your thinking but it’s napalm glands are only active in angry mode. If he fails to put down the fire after two sweeps, he backs away to save his skin.
This project is based on an Arduino processor and MotorShield. Two gear motors with 224:1 ratios and PolyMorph axle extensions are used for movement. Puff moves his head to left and right with the help of a servo and does that in a 60-120 degree range. His “eyes” are two light sensing resistors, each one placed at the end of a heat shrinking tube so that localization of the fire is more precise. Also you must isolate the back of the resistors as well, for the same reason.
Once his eyes are fixed on the fire his breath comes from a little fan and it’s motor. A Sharp IR sensor provides cliff and obstacle detection. You will have to angle it so that it’s focus point falls at 10cm away on the floor. The Dragon’s head is made of paper that you can print with your desired model.
Ever wondered what’s inside a head mounted spy gadget? Well, now you have the answer, there was somebody curios enough to take apart a robot toy which had a camera and eye piece, considering the size, isn’t a James Bond type of gadget so don’t expect to find any nanotechnology inside, but you can see how the LCD displays work. Even your LCD monitor uses the same solutions, only in bigger.
This post is for people curios enough to dismount similar electronics, my advice : don’t, you won’t find any components inside which you can use, or there are hard to remove from the pcb and if you damage the flexible pcb or any other part, you probably can’t repair it
This is an advanced robotics project, the robot arms follows a moving object, anyway that’s the idea. The arms moves a little sloppy, it surely isn’t in the final stage of development, but the author explains what problems encountered. The motion is detected using IR leds and receivers, and subtracting the ambient light from the readings to get the reflected light from the object which is tracked.
If you are interested in motion tracking this is a good place to start, my opinion is that the analog part needs to be reviewed, the IR leds should be mounted inside a tube, otherwise interferes with the reflected light and reduces the sensibility.
