adc0804_中文资料（Adc0804_ Chinese information）

adc0804_中文资料（Adc0804_ Chinese information） adc0804_中文资料(Adc0804_ Chinese information) /CS chip select signal. /CS chip select signal. Analog / digital converter (related knowledge) The basic principle of A/D converter ----ADC0804 1, what is called The A/D converter is analog Digital converter (digital converter) ADC) converts analog signals into digital signals. The signal input is OK Is the output of the sensor or converter, and ADC digital signals may also be provided to microprocessors for wide application. 2, Specification and pin diagram of ADC0804 8 COMS, in turn, approximate type A/D converter . Three state lock output Access time : 135US Resolving power: 8 Conversion time: 100US Total error: plus minus 1LSB Operating temperature: ADC0804LCN---0~70 degrees Pin drawings and instructions are shown in figures One /RD control output signal of external read conversion result. /RD HI, DB0~DB7 handles high impedance: /RD for LO, digital data will be Output. /WR: the control input used to start the transition, which is equivalent to the start of the ADC conversion (/CS=0), when the /WR is converted from HI to LO, the converter is cleared Except: when /WR returns to HI, the conversion begins formally. CLK IN, CLK R: the clock input or the oscillator is not C (R), the frequency is limited to 100KHZ~1460KHZ, and if the RC circuit is used, the The oscillation frequency is 1/ (1.1RC) /INTR: interrupt request signal output Low altitude action VIN (+) VIN (-): differential analog voltage input. Input single ended positive voltage, VIN (-) ground: differential input, Join directly VIN (+), VIN (-) AGND, DGND: analog signals, and grounding of digital signals VREF: auxiliary reference voltage . DB0~DB7:8 bit digital output . VCC: power supply as well as the reference voltage of the circuit . Reference dragon Suite 0804 diagram: Sixteen binary binary code and full scale relative voltage VREF=2.560 Volts High four bit byte, low four bit byte, high four bit, low voltage, four bit voltage F 1111, 15/16, 15/256, 4.800, 0.300 E 1110, 14/16, 14/256, 4.480, 0.280 D 1101, 13/16, 13/256, 4.160, 0.260 C 1100, 12/16, 12/256, 3.840, 0.240. B 1011, 11/16, 11/256, 3.520, 0.220. A 1010, 10/16, 10/256, 3.200, 0.200 91001 9/16 9/256 2.880 0.180 81000 8/16 8/256 2.560 0.160 70111 7/16 7/256 2.240 0.140. 60110 6/16 6/256 1.920 0.120. 50101 5/16 5/256 1.600 0.100 40100 4/16 4/256 1.280 0.080 30011 3/16 3/256 0.960 0.060 20010 2/16 2/256 0.640 0.040. 10001 1/16 1/256 0.320 0.020. 0000000 Example: VIN=3V, as shown in the chart above 2. 880+0.120=3V for 10010110=96H Function description 1, ADC0804 converts input analog values to digital values and outputs them to P0, to make correspondence LED light. For example, enter The output of 3V and ADC0804 should be 96H=10010110, this digital signal is sent in 8051 P1, and then... P1 deposit 8051 accumulator, and then accumulator to P0, so that the corresponding LED Bright. 2, first ADC0804 reference voltage VREF is adjusted to 2.56V. (in the Dragon suite mainly demonstrates the principle, not the precise adjustment of the voltage used Two individual 1K resistance partial pressure, about 2.5V) 3 adjustments ADC0804 VIN variable resistor. By 0V transfer to 5V is observed in terms of its relationship P1 LED change . Reference program: 0804 basic applications, rotating potentiometer, P0 port displays the number taken / / definition; ADC connection port Ad_cs equ P3.6 Ad_wr equ P2.0 Ad_rd equ P3.7 Ad_input_port equ P1 Org 0000H ajmp主要 org 0030h 主要: LCALL adc_demo ajmp主要 ;// ========================================== ;//启动 广告转换 ;// ========================================== adc_start: CLR ad_cs NOP CLR ad_wr NOP ad_wr SETB NOP ad_cs SETB NOP RET;/ / ========================================== ;//读 广告转换 ;// ========================================== adc_read: MOV ad_input_port，# 0ffh CLR ad_cs NOP CLR ad_rd NOP NOP MOV A，ad_input_port NOP ad_rd SETB NOP ad_cs SETB RET ;// ========================================== ;//广告转换读取延时程序，显示读到的数值 ;// ========================================== adc_demo: LCALL adc_start LCALL delay1ms LCALL adc_read CLR P2.0 CLR P2.3 mov P0，一 RET delay1ms: MOV R7，# 10 TT1: MOV R6，# 50 djnz R6，2us美元; djnz R7，TT1 RET 结束