TFRH Robot Analysis

TFRH robot is based on embedded system. The TFRH has mainly two Atmel AT89S52 microcontrollers which communicate with each other via an RF module 434 Mhz. This will be explained in the forthcoming sections.
The TFRH is based on 8-bit microcontroller The IC used was Atmel AT89S52 ICS. The hardware cost is reduced by removing various sub ICs used in the design. The design part had successfully removed the 8255 IC and had used multiplexer cd 4051 to support the 7 different motor for the various function. The external clock is supplied by an 11.0592 crystal.
The electronic hardware design comprises of two microcontrollers. One controls all the seven motors including LCD, KEYPAD, RF module receiver 434MHZ and it counterpart controls the IR sensor
This is because of the fact that most of the operation dealing the robot and calculations carried out by the Robot is been calculated and executed by this microcontroller. The ports of the second microcontroller has been completely used for the connection of the peripherals and in order to in co-operate the 7 DC geared motors two CD4051 3 input multiplexer is used. Based on combination of the 3 inputs of the multiplexer the motors movement are controlled. The detailed explanation of the circuit is give in the preceding paragraphs.
Peripherals and brief summary of the 8051 microcontroller. TFRH is a microcontroller based project. In this project a 8 bit microcontroller is been used. 8051 microcontroller is a 40 pin DIP IC(in case of TFRH).
FIG 20: PIN DIAGRAM OF AN 8051 microcontroller 8051 is a 40 pin IC with 4 ports each having 8 subports. The ports are P0,P1,P2,P3. Each support is denoted as Px.1…..Px.8 where x stands for 0 to 3. Out of the four ports, when using port 0, it has be externally provide with either pull up or push up resistors, all other ports have it internally. Any of the ports can be configured either an input or output port by writing either 0 or 1 to the port before. When 0 is written to the port becomes an output port and when the port is given a 1, the port becomes an input
However, each of these eight pins also has an alternate function, as detailed in the table below. Like all electronic device to work, a external or clock source should be present. In the case of 8051 microcontroller, the clock is supplied by an external oscillator preferably 11.0592 MHz oscillator to induces the clock pulses. The out of the clock source is connected to pin number 18 and 19 and is termed as XTAL1 and XTAL2. Pins 40 and 31 are given to VCC of +5V. Pin 31 is , which is called the external access, on pin 31, is used for enabling or disabling the on-chip ROM. When tied high (5V), the 8051 executes instructions in internal ROM when executing in the lower 4K (8K for the 8052) of memory. If tied low the 8051 will always execute instructions in external memory. The 8031 and 8032 should always have pin 31 tied low as there is no internal code memory.
ALE - the address latch enable is on pin 30. The ALE is used for latching the low byte of the address into an external register. - the program store enable is an output signal on pin 29. This signal is used for fetching instructions from external code memory.
RST- this pin is for resetting the IC, that is loading the PC(program counter) with start up