DAC With MCS51 Microcontroller
The figure below shows the Configuration DAC With artificial MCS51 Microcontroller National Semiconductor, capacitors C1, C2 and form a series of 12 MHz XTAL oscillator, capacitor C3 and resistor R1 form a series reset. 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 Configuring DAC with MCS51 Microcontroller
C3 is mounted on leg 16 and ground is useful for stabilizing the voltage generated. DAC0800 and LM741 using voltage source +12 Volt and -12 Volt, is somewhat different from the voltage that is usually used for digital circuits, so that digital signals can be received well IC DAC0800, DAC0800 equipped foot VLC (pin 1) for various voltage levels menyesesuaikan types of digital ICs. In the DAC0800 data sheet are shown in various series to be installed on this leg for DAC0800 can be used for a variety of digital IC family. In the circuit of Figure above, the DAC0800 is connected to the microcontroller MCS51 family who work at TTL voltage levels, for this purpose VLC leg connected to ground.
Behind the legs of the IC DAC0800 B1 through B8 are not equipped to accommodate a latch that is fed a digital scale, changing the combination of digital signals on the legs is a direct result of output voltage change. Construction inputs such DAC0800, DAC0800 result can not be connected directly to a channel-data (data bus) microprocessor system, the relationship DAC0800 to the processor must pass through the parallel port. 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 condition of the circuit is formed. Instructions to remove the voltage in the circuit of Figure 1 is very simple, just mamakai instruction MOV P1, A analog scale with the understanding that wish to be raised previously been stored in the accumulator A.