how to load program for at89c51 controller

MAIN:ACALL SMPCK // checks the level of the sump tank MOV P0,#11111111B // initiates P2 as the output port MOV P2,#11111111B // initiates P2 as sensor input Water level controller using 8051 Program. The circuit diagram of the water level controller is shown in the figure below. When the water level in the sump tank goes low, the controller makes P0.7 low which makes LED D7 to glow. Also the LED d6 glows indicating the motor is ON. When ever it is required start pumping, the controller makes P0.5 low which makes transistor Q6 ON which in turn activates the relay K1 that switches the pump. Port pin P0.5 is used to control the pump.

All these port pin are high (all sensor probes are open) means the tank is empty. The same applies to other sensor probes (3/4, 1/2, 1/4) and the microprocessor understands the current level by scanning the port pins P2.4 ,P2.5, P2.6 and P2.7. Now its collector voltage goes high and high at P2.4 means the tank is not full. When water level goes below the full level probe, the base of Q2 becomes open making it OFF. The collector of Q4 is connected to P2.4 and a low voltage at P2.4 means the over head tank is not FULL. Whenever water rises to the full level current flows into the base of transistor Q4 which makes it ON and so its collector voltage goes low.

Consider the topmost (full level) probe, its other end is connected to the base of transistor Q4 through resistor R16. The probes for sensing 1/4, 1/2, 3/4 and FULL levels are placed with equal spacing one by one above the bottom positive probe. A positive voltage supply probe goes to the down bottom of the tank. Have a look at the sensor probe arrangement for the overhead tank in Fig1. The level sensor probes for the overhead tank are interfaced to the port 2 of the microcontroller through transistors.

How to load program for at89c51 controller