DAC Interfacing with 8051.pdf
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This document discusses interfacing a digital-to-analog converter (DAC) with an 8051 microcontroller. It explains that a DAC is used to convert digital pulses from the 8051 into analog signals that can be read by systems requiring analog inputs. Specifically, it describes using an 8-bit DAC 0808 chip to convert digital data from the 8051 into a corresponding analog output voltage. It also provides 8051 assembly code examples to generate triangular and square wave outputs using a DAC interfaced with an 8051 port.
![Interfacing DAC with 8051 T.Srikrishna , M.Sc, M.Tech, GVP
Exmple:
1. IF data =00H [00000000], Vref= 10V
Therefore, V0= 0 Volts.
2. If data is 80H [10000000], Vref= 10V
Therefore, V0= 5 Volts.
Different Analog output voltages for different Digital signal is given
as:](https://image.slidesharecdn.com/dacinterfacingwith8051-230427074224-759f7db2/85/DAC-Interfacing-with-8051-pdf-3-320.jpg)
DAC Interfacing with 8051.pdf
- 1. Interfacing DAC with 8051 T.Srikrishna , M.Sc, M.Tech, GVP DAC Interfacing with 8051 The DAC is a device widely used to convert digital pulses to analog signals. Here we will discuss the basics of interfacing a DAC to 8051. In these systems MC generates output which is in digital form. But the controlling system requires analog signal as they don't accept digital data. Thus it necessary to use DAC which converts digital data into equivalent analog voltage. In the figure shown, we use 8-bit DAC 0808. This IC converts digital data into equivalent analog Current. Hence we require an I to V converter to convert this current into equivalent voltage. The two methods of creating a DAC is Binary weighted and R/2R ladder network. We will also see the triangular and square wave generation.
- 2. Interfacing DAC with 8051 T.Srikrishna , M.Sc, M.Tech, GVP In the DAC0808, the digital inputs are converted to current (Iout), and by connecting a resistor and op-amp to the Iout pin, we convert the result to voltage Vo. According to theory of DAC Equivalent analog output is given as:
- 3. Interfacing DAC with 8051 T.Srikrishna , M.Sc, M.Tech, GVP Exmple: 1. IF data =00H [00000000], Vref= 10V Therefore, V0= 0 Volts. 2. If data is 80H [10000000], Vref= 10V Therefore, V0= 5 Volts. Different Analog output voltages for different Digital signal is given as:
- 4. Interfacing DAC with 8051 T.Srikrishna , M.Sc, M.Tech, GVP 8051 Assembly code to generate triangular wave ORG 0000H CLR A UP: INC A MOV P2,A CJNE A, #0FFH, UP DOWN: DEC A MOV P2,A CJNE A, #00, DOWN SJMP UP END 8051 Assembly code to generate SUARE wave ORG 0000H BACK MOV A, #00H UP; MOV P1,A CALL DELAY DOWN: MOV A,FFH MOV P1,A CALL DELAY SJMP BACK. DELAY: MOV R2,#0FFH WAIT: DJNZ R2, WAIT RET