In this project we will use ADXL335 Accerlerometer Tilt sensor. It measure 3 d Changes . according ot it give variable voltage out put. We can measure receiver output using LM358 or LM 324 as a comparator circuit. we compare reference voltage with in put from x.y, and z from adxl335 sensor. Few people say adxl335 as a sensor and few only module.
We can use ADC circuit with this module also. We are getting low high pulse from LM324 . we used 3 comparator circuit in single LM324. LM 324 is a quad operation amplifier means having 4 op amp circuit.
We divided project in to two parts
- Part1 in which we used accerometer and get output from LM324
- Part2 in which we used RF controlled Robot using FPGA or CPLD.
In part 1 as I explained we used LM 324 as a comparator circuit. we give out put of LM 324 to RF transmitter circuit. in RF robot we control robot with Four switches available on RF transmitter circuit. we use 4 microswitches . in part 2 we checked RF robot with these four switches. If we press any switch then our robot move forward, backward, left and Right according to it. We give out put of LM 324 to these four switches.
Pin no 40 is connected to the positive supply. In this project we provide a 5 volt dc power supply. This power supply is truly regulated power supply. Pin no 20 is connected to the negative supply. Here we supply a negative voltage on this pin. Crystal is connected to the pin no 4 and 5 of the microcontroller. Crystal provide a clock signal to run the vehicle and process all the internal requirement of the circuit. We use two sensor and these two sensor are connected to the p3.4 and p3.5 of the microcontroller.For the regulated power supply we use ic 7805 as a regulator to provide a fix 5 volt power supply.
When we move the robot on surface then infra red light is not reflected from the surface. When infra red light is not reflected from the surface then infra red sensor is not getting a signal. We program the robot like this when sense the light then it means position of sensor is on the surface. If the sensor is on white line then one motor change its direction and due to that robot change its path and when both the sensor on surface then only vehicle move forward. We use two sensor for two motor’s. if the both the sensor on surface then vehicle move forward , if one sensor is noton surface then vehicle change its direction. Microcontroller provide a signal to the motor circuit. Motor is not directly connected with the microcontroller. For the safety of the main processor we interface the motor with optocoupler circuit. Here we use pc 817 ( 4 pin opto coupler) to interface the micro controller with the motor circuit. We use H bridge circuit with the motor. H bridge basically control the movement of the motor. With the help of this H bridge we change the direction of the motor. We use four transistor circuit with each motor. We are using four transistor circuit. Out of these four transistor two transistor is NPN and two transistor and PNP transistor. One NPN and One PNP provide a one direction voltage and motor moves on one direction. Second NPN and second PNP transistor again change the direction of the motor automatically.