Digital scale is given to the B1 to B7 (leg 5 to 12) in the IC DAC0800, the binary value of the digital scale was converted into an analog magnitude of the current at IOUT (ft 4 DAC0800) and IOUT * (feet 2 DAC0800), then by IC Operational Amplifier LM741 flow is converted into voltage. The resulting voltage expressed by the formula shown in Figure below, in addition to depending on a digital scale weight value is given, this voltage depends on the size of Vref (DAC0800 14 feet).
|figure.1 DAC With MCS5 Microcontroller|
In Figure 1, the DAC0800 is connected to the parallel port P1 from AT89Cx051. Connecting the DAC0800 to the other MCS51 family, for example AT89C51, can pass parelel ports P0, P1, P2 or P3, depending on the conditions established series. Instructions to remove the voltage in the circuit of Figure 1 is very simple, just use instruction MOV P1, A analog scale with the understanding that wish to be raised previously been stored in the accumulator A.