A study of tele-operated intelligent mobile robots
- Hardware description
- AT89S52 micro-controller
- Architechture of ATMEL 89S52 micro-controller
- Connection diagrams
- Advantages and disadvantages of L293D
- Regulated power supply
- Hardware design
- Software design
- Language extensions
- Future enhancements
Real time embedded systems are time-critical systems that are hard to implement as compared to traditional software, due to large numbers of conflicting requirements. This project describes an application of advance modeling techniques to improve the development of embedded systems. In our project we are going to explain one of the most successful applications of a robot called the Tele-operated intelligent mobile robot in which a couple of mobile phones are connected and used as the transmitting and reception media. The main objective of the project is to develop the robot using embedded technology to reduce the complexity in design and control the movement of robot using cell phone.
This is implemented using DTMF technology. A cell phone is connected to the robot. When a call is made from another cell phone to the one attached to the robot, automatically the call gets lifted and the robot starts acting according to the commands given by the caller. The microcontroller is interfaced with dc motors through the line driver.
The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes of in-system programmable Flash memory. The device is manufactured using Atmel's high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 instruction set and pin out. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with in-system programmable Flash on a monolithic chip, the Atmel AT89S52 is a powerful microcontroller which provides a highly-flexible and cost-effective solution to many embedded control applications. In addition, the AT89S52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes.
[...] XTAL2: Output from the inverting oscillator amplifier INTERRUPTS The AT89S52 has a total of six interrupt vectors: two external interrupts (INT0 and INT1), three timer interrupts (Timers and and the serial port interrupt. Each of these interrupt sources can be individually enabled or disabled by setting or clearing a bit in Special Function Register IE. IE also contains a global disable bit, EA, which disables all interrupts at once. Timer 2 interrupt is generated by the logical OR of bits TF2 and EXF2 in register T2CON. [...]
[...] The operation of a DC motor is dependent on the workings of the poles of the stator with a part of the rotor, or armature. The stator contains an even number of poles of alternating magnetic polarity, each pole consisting of an electromagnet formed from a pole winding wrapped around a pole core. When a DC current flows through the winding, a magnetic field is formed. At its center is the rotor, a coil wound around an iron armature, which spins within the poles of the magnet that can be seen on the inside of the casing. [...]
[...] In normal operation, ALE is emitted at a constant rate of 1/6 the oscillator frequency and may be used for external timing or clocking purposes. However, that one ALE pulse is skipped during each access to external data memory. If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode. [...]