Procedure for making a circuit. 19

in this post i will include both circuit. since the process are the same i will be only explaining it once.

STEP 1

STEP 2

STEP 3

STEP 4

STEP 5

STEP 6

STEP 7

STEP 8

STEP 9

STEP 10

STEP 11

STEP 12 

STEP 13

STEP 14

STEP 15

PCB Layout Transmitter (ROBOT) 18

this is the PCB layout for the transmitter.

PCB 1

PCB 2

PCB 3

PCB Layout controller 17

this is for the PCB layout of the controller

PCB 1

PCB 2

PCB 3

Starting the project. 16

From here on i will start on developing the project. i hope everything will go well as planned. lets hope for the best and see what we have in the end of the project.

Interfacing GP2D12 with PIC 15

The GP2D12 is an analog infrared proximity sensor. It can be used to detect obstacles. This sensor has a LED that emits infrared light. Infrared light has the interesting property that it bounces on obstacles. On the front of the sensor, beside the LED that emits the infrareds, there is a photodiode that is sensible to infrared light. It will vary the output voltage based on the amount of infrared light that bounces back to the sensor. Roughly speaking, the more infrared light it sees, the closer is the object and the higher the output voltage generated by the photodiode.

If the voltage output is connected to a microcontroller with analog to digital conversion capability (such as a PIC16F877 microcontroller), it is possible to translate this voltage to a numerical value. This value can be used to determine whether or not there are obstacles close to the sensor and how far these obstacles are.

The GP2D12 circuit shows how to interface a PIC16F877 microcontroller to a Sharp GP2D12 sensor.

Note that in this example, it is assumed that the sensor is tucked in ten centimeters within the robot. This is necessary because the voltage output curve climbs for the first ten centimeters and then drops (see chart below), which means that there is a range of voltage values that account for two different distances. By placing the sensor inside the robot, we avoid this ambiguity in sensor reading.

Analog Output Voltage vs Detection Distance

The GP2D12 outputs a non-linear analog voltage corresponding to the distance of the reflective object. The sensor can measure in the range from 10-80 cm. The voltage is approximately 2.4V at 10cm and at 0.52 at 60cm. The sensor draws about 34mA. The maximum is stated to be 50mA.

Sharp GP2D12 14

Sharp GP2D12

.With the introduction of the GP2D12 line of Sharp detectors, a new approach was developed that not only gives object detection at a longer range than the previous method, but also offers range information.This new rangers offer much better immunity to ambient lighting conditions because of the new method of ranging.

This sensor use triangulation and a small linear CCD array to compute the distance and/or presence of objects in the field of view.  The basic idea is this: a pulse of IR light is emitted by the emitter.  This light travels out in the field of view and either hits an object or just keeps on going.  In the case of no object, the light is never reflected and the reading shows no object.  If the light reflects off an object, it returns to the detector and creates a triangle between the point of reflection, the emitter, and the detector.

General Description

The Sharp GP2D12 is an analog distance sensor that uses infrared to detect an object between 10 cm

and 80 cm away. The GP2D12 provides a non-linear voltage output in relation to the distance an object

is from the sensor and interfaces easily using any analog to digital converter.

Features

• High immunity to ambient light and color of object

• No external control circuitry required

• Sensor includes convenient mounting holes

• Compatible with all BASIC Stamp® and SX microcontrollers.

The Motor Drivers (L293D) 13

The Motor Drivers
Motor are high-powered devices in the world of digital electronics. A typical digital output can supply about 10 to 20 mA of current. A small magnet motor requires anywhere from 500 to 4000 mA of current. Special circuits are therefore required to drive motors

The H-Bridge Circuit.

H-bridge Circuit

A circuit known as the H-bridge (named for its topological similarity to the letter H) is commonly used to drive motors. in this circuit ( shown above), two of four transistors are selectively enabled to control current flow through a motor.

The H-bridge with left to right current flow

as shown above, an opposite pair of transistors( Transistor One and transistor three) is enabled, allowing current to flow through the motor. The other pair is disabled, and can be thought of as out of the circuit. by determining which pair of transistors is enabled, current can be made to flow in either of the two directions through the motor. Because permanent magnet motors reverse their direction of turn when the current flow is reversed, this circuit allows bidirectional control of the motor.

L293D

The L293D is a dual h-bridge driver IC. The IC is also referred to as a push-pull four channel driver. An h-bridge is ideal for driving motors. The L293D provides two h-bridges for driving both motors on the robot base. The motor direction is controlled by logic signals from the microcontroller. Two signals per motor are required to control the direction.