Rangkaian Jam Digital Mikrokontroler

| | Label: mikro

Digital hours to make this not too difficult. This series is not my original project, I trace the series of files and program from the internet, there is no chance the program listing. After I download the file to its hex-hour direct way. This clock only displays hours and minutes, to seconds However you can install the led associated with a series of I Hz oscillator formed from IC 555 (which I do, because I do not know the program listing), 2 led in parallel and installed as a bookmark seconds. Led to two installed in the middle of the hours and minutes. Although with the way that seconds and minutes if observed (calculated) decline slightly but I'm not the problem, Moreover people will not know about it. Digital hours following scheme:

Circuit digital watch

To me its PCB design itself, of course are still using my favorite software, PCB designer. Next the PCB layout (look up) :

PCB layout of digital watch

• PCB file can download it here. • Hex file. can be downloaded here.

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Rangkaian downlowder AT89C51

| | Label: mikro

Atmel is a product AT89S51/AT89S52 that quite a lot in the market with a price of less than 20 thousand rupiah. To start learning mikrokontroler type 89S51 this we need a programmer And Rangkaian Downloader. Programmer is a hardware device that is used to enter the machine language program code compilation that we write to in mikrokontroler.

Gambar Skema Rangkaian Downloader AT89S51/AT89S52picture above shows the circuit diagram of the in-system programmer interface, the power to the interface is provided by the target system. The 74HCT541 ic isolate and buffer the parallel port signals. It is necessary to use the HCT type ic in order to make sure the programmer should also work with 3V type parallel port.

Skema rangkaian downloader ini can be use to program the 89S series devices and the AVR series devices which are pin compatible to 8051, like 90S8515. For other AVR series devices the user can make an adapter board for 20, 28 and 40 pin devices. The pin numbers shown in brackets correspond to PC parallel port

connector.

Software ISP

The ISP-30a.zip file contains the main program and the i / o port driver. Place all files in the same folder. The main screen view of the program is shown in the picture below.

Following are the main features of this software,

• Read /write the Intel Hex file • Read the signature, lock and fuse bits • Clear/Fill memory buffer • Verify with memory buffer • Reload current Hex File • Display buffer checksum • Program selected lock bits & fuses • Auto detection of hardware

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Rangkaian Saklar Dan Keypad Metrix mikrokontroler AT89S51/52

| | Label: mikro

Rangkaian saklar for mikrokontroler AT89S51/52

Port mikrokontroler AT89S51/52 The complete internal pull-up, a default condition so that it is high. To make this port as input, we live to provide logic high or ignore in the default condition. If we want a legible entries we should use the Low input signal.

In the picture below, when the button on the keypad and press the low signal will be sent to port 3 on mikrokontroler, Thus, this port will have a logic in accordance with the key emphasis

Skema Rangkaian Mikrokontroler dengan masukan Saklar

;---------------------------------------------------------------------; Simulasi penekanan tombol pd P3.0 untuk menghidupkan; dan P3.1 untuk mematikan LED pada Port 1;----------------------------------------------------------------------ORG 0HMULAI:MOV A,P3 ; Baca port 3CJNE A,#0FEH,TERUS ; Apakah isi akumulator = 11111110BMOV P1,#000H ; Ya! Hidupkan lampu LED di port 1SJMP MULAI ; Ulangi lagi dari awalTERUS:CJNE A,#0FDH,MULAI ; Apakah isi akumulator = 11111101BMOV P1,#0FFH ; Ya! Matikan lampu LED di port 1SJMP MULAI ; Ulangi lagi dari awalEND

program on the work which led to the connects to the port 1, while s1 in press led will be flame and when off in the pressm S2

program on the work, which led to the connects to the port 1, while s1 in press, and led a

flame, and when out in the press and S2

How it works, the program:When the switch connected to P3.0 in the press, the data on the port 3 is 11111110 binary or 0FE Hexa, the program will know the content of the port 3 if data is same (0FE H) Led then switched to the port 1, if any emphasis P3.1 , the data on the port 3 11111101 binary or 0FD Hexa, program will check the content of port 3 if data is found in the Led on the port 1 will be turned off

Rangkaian Keypad Matrix

4 x 4 Keypad is a keypad measuring 4 columns x 4 rows. This module can be enabled as an input in the applications such as digital security, datalogger, attendance, motor speed controllers, robotik, and so forth.

Hardware Specifications

• Has a 16 button (function button depending on the application). • Configuration has 4 lines (input scanning) and column 4 (output scanning).

Skema Rangkaian Mikrokontroler dengan masukan Keypad

;=======================================; PROGRAM KEYPAD 4X4 DIPASANG; PADA PORT 0, OUTPUT PADA PORT 1;=======================================KOLOM1 BIT P0.0KOLOM2 BIT P0.1KOLOM3 BIT P0.2KOLOM4 BIT P0.3BARIS1 BIT P0.4

BARIS2 BIT P0.5BARIS3 BIT P0.6BARIS4 BIT P0.7KEYPORT EQU P0 ; KEYPAD CONNECT KE PORT 0KEYDATA EQU 50H ; MEMORY DATA UNTUK KEYPADKEYBOUNC EQU 51H ; MEMORY UNTUK ANTI BOUNCINGORG 0HULANG:CALL KEYPAD ; PANGGIL SUB RUTIN KEYPADMOV A,KEYDATACJNE A,#0FFH,DITEKANJMP ULANGDITEKAN:CPL AMOV P1,ADJNZ R0,$JMP ULANGKEYPAD:MOV KEYBOUNC,#100 ; KONSTANTA ANTI BOUNCINGMOV KEYPORT,#0FFH ; PORT KEY PADCLR KOLOM1 ; SCAN KOLOM 1UL1: JB BARIS1,KEY1 ; TOMBOL 1 DITEKAN?CALL DELAYDJNZ KEYBOUNC,UL1MOV KEYDATA,#1 ; ISI REG. DATA DGN 1RETKEY1: JB BARIS2,KEY2 ; TOMBOL 2 DITEKAN?CALL DELAYDJNZ KEYBOUNC,KEY1MOV KEYDATA,#4RETKEY2: JB BARIS3,KEY3CALL DELAYDJNZ KEYBOUNC,KEY2MOV KEYDATA,#7RETKEY3: JB BARIS4,KEY4CALL DELAYDJNZ KEYBOUNC,KEY3MOV KEYDATA,#0AHRETKEY4: SETB KOLOM1CLR KOLOM2JB BARIS1,KEY5CALL DELAYDJNZ KEYBOUNC,KEY4

MOV KEYDATA,#2RETKEY5: JB BARIS2,KEY6CALL DELAYDJNZ KEYBOUNC,KEY5MOV KEYDATA,#5RETKEY6: JB BARIS3,KEY7CALL DELAYDJNZ KEYBOUNC,KEY6MOV KEYDATA,#8RETKEY7: JB BARIS4,KEY8CALL DELAYDJNZ KEYBOUNC,KEY7MOV KEYDATA,#0RETKEY8: SETB KOLOM2CLR KOLOM3JB BARIS1,KEY9CALL DELAYDJNZ KEYBOUNC,KEY8MOV KEYDATA,#3RETKEY9: JB BARIS2,KEY10CALL DELAYDJNZ KEYBOUNC,KEY9MOV KEYDATA,#6RETKEY10: JB BARIS3,KEY11CALL DELAYDJNZ KEYBOUNC,KEY10MOV KEYDATA,#9RETKEY11: JB BARIS4,KEY12CALL DELAYDJNZ KEYBOUNC,KEY11MOV KEYDATA,#0BHRETKEY12: SETB KOLOM3CLR KOLOM4JB BARIS1,KEY13CALL DELAYDJNZ KEYBOUNC,KEY12MOV KEYDATA,#0CHRET

KEY13: JB BARIS2,KEY14CALL DELAYDJNZ KEYBOUNC,KEY13MOV KEYDATA,#0DHRETKEY14: JB BARIS3,KEY15CALL DELAYDJNZ KEYBOUNC,KEY14MOV KEYDATA,#0EHRETKEY15: JB BARIS4,KEY16CALL DELAYDJNZ KEYBOUNC,KEY15MOV KEYDATA,#0FHRETKEY16: MOV KEYDATA,#0FFHRETDELAY:DJNZ R0,$RETEND0 komentar Kirimkan Ini lewat Email BlogThis! Berbagi ke Twitter Berbagi ke Facebook Berbagi ke Google Buzz

Gambar Rangkaian Sensor Pengukur Suhu

| Senin, 08 Maret 2010 | Label: sensor-sensor This circuit measures the water temperature. this circuit use IC CA3161 and CA3162 for control all, The Temperature Value can’t be keep always while no power supply as It hasn’t EEPROM to save. This circiut will be display for you monitoring only that is make sense to implement in water.

The IC CA3161 is a counter and 7segment LED driver to display amount of temperature on 7segments. About a temperature sensor is a diode which number 1N4148. This is like of the Car Radiator. Connect to the 5 Vdc power supply from Car Battery that you can use a LM7805 for +5Vdc regulation with low cost voltage regulator.

Skema rangkaian pengukur suhu air

For the method of temperature measurement: first after application of at least 2 currents of a thermal sensor, including at least two output signals are generated calculating an analog signal to the temperature of the reaction at least two signals, the analog signal representative of temperature to the temperature sensors, a calibration, the calibration factor is calculated by applying the order of leastthree thermal sensor, and calibration of a gap in the temperature of the concept of analog signal, that the development gap-term is at least a series of parasite resistance to the thermal temperature sensor and the signal processing theanalog digital signal to a temperature reference value for the conversion of the reference value for the transition is consistent with the calibration.

IC LM340A Sesor Suhu

The LM340A monolithic 3-terminal positive voltage regulators employ internal current-limiting, thermal shutdown and safe-area compensation, making them essentially indestructible. If adequate heat sinking is provided, they can deliver over 1.0A output current.

Parameters IC LM340A

• Output Current: 1000 mA• Output Voltage: 7.5, 12, 15, 8, 5 Volt• Input Min Voltage: 7.5, 14.8, 10.5, 17.9 Volt• Input Max Voltage: 35 Volt• Temperature Min: 0 deg C• Temperature Max: 70, 125 deg C• RegType: Linear Regulator

IC CA3161E Description

The CA3161E is a monolithic integrated circuit that performs the BCD to seven segment decoding function and features constant current segment drivers. When used with the CA3162E A/D Converter the CA3161E provides a complete digital readout system with a minimum number of external parts.

Absolute Maximum Ratings IC CA3161E

• DC VSUPPLY (Between Terminals 1 and 10) . . . . . . . . . . . . . .+7.0V• Input Voltage (Terminals 1, 2, 6, 7). . . . . . . . . . . . . . . . . . . . . .+5.5V• Output Voltage• Output “Off”. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +7V• Output “On” (Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +10V

IC CA3162E Description

The CA3162E are I2L monolithic A/D converters that provide a 3 digit multiplexed BCD output. They are used with the CA3161E BCD-to-Seven-Segment Decoder/Driver and a minimum of external parts to implement a complete 3-digit display. The CA3162AE is identical to the CA3162E except for an extended operating temperature range.

Absolute Maximum Ratings IC CA3162E

• DC Supply Voltage (Between Pins 7 and 14) . . . . . . . . . . . . . +7V• Input Voltage (Pin 10 or 11 to Ground). . . . . . . . . . . . . . . . . . . 15V• Temperature Range CA3162E. . . . . . . . . . . . . . . . . . . . . . . . . . .0 to 75oC• Temperature Range CA3162AE . .. . . . . . . . . . . . . . . . . . . . . . -40oC to 85oC• Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . 150oC• Maximum Storage Temperature Range . . . . . .. . . . . . . . . . . . .-65oC to 150oC• Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . . 300oC.

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Gambar Rangkaian Sensor Pendeteksi Warna

| | Label: sensor-sensor sorThis circuit can sense eight colours, i.e. blue, green and red (primary colours); magenta, yellow and cyan (secondary colours); and black and white. The circuit is based on the fundamentals of optics and digital electronics. The object whose colour is required to be detected should be placed in front of the system.

Skema Rangkaian Sensor Pendeteksi Warna

Note:

• Potmeters VR1, VR2 and VR3 may be used to adjust the sensitivity of the LDRs.• Common ends of the LDRs should be connected to positive supply.• Use good quality light filters.

The light rays reflected from the object will fall on the three convex lenses which are fixed in front of the three LDRs. The convex lenses are used to converge light rays. This helps to increase the sensitivity of LDRs. Blue, green and red glass plates (filters) are fixed in front of LDR1, LDR2 and LDR3 respectively. When reflected light rays from the object fall on the gadget, the coloured filter glass plates determine which of the LDRs would get triggered. The circuit makes use of only AND gates and NOT gates.

When a primary coloured light ray falls on the system, the glass plate corresponding to that primary colour will allow that specific light to pass through. But the other two glass plates will not allow any light to pass through. Thus only one LDR will get triggered and the gate output corresponding to that LDR will become logic 1 to indicate which colour it is. Similarly, when a secondary coloured light ray falls on the system, the two primary glass plates corres- ponding to the mixed colour will allow that light to pass through

while the remaining one will not allow any light ray to pass through it. As a result two of the LDRs get triggered and the gate output corresponding to these will become logic 1 and indicate which colour it is.When all the LDRs get triggered or remain untriggered, you will observe white and black light indications respectively.

The LDR is mounded in a tube, behind a lens, and aimed at the object. The coloured glass filter should be fixed in front of the LDR as shown in the figure. Make three of that kind and fix them in a suitable case. Adjustments are critical and the gadget performance would depend upon its proper fabrication and use of correct filters as well as light conditions.

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Rangkain Pendeteksi Suhu

| | This is a circuit that serves to indicate various levels of hot water in a tank. SW1 is a normally open press button switch which allows you to view the level of hot water in a hot water tank. When pressed the voltage difference at the junction of the thermistor and preset is compared to the fixed voltage on the op-amps non-inverting input. Depending on the heat of the water in the tank, the thermistors resistance will toggle the op-amp output to swing to almost full voltage supply and light the appropriate LED.

Skema rangkaian indikator suhu air

Note:

• Op-Amp: LM324 or any quad opamp can be used or even four single op-amps.

• R2-R5: 330ohm resistors, but Lower values give brighter LED output.• NTC1-4: Cold resistance was around 300K, hot resistance 15k. Alternative

thermistors may be used with different resistance ranges, but the presets P1 to P4 must also be changed as well.

• R7-10: only required if your thermistors resistance is several ohms at the hottest temperature.

• P1 - P4: Chosen to match the resistance of the thermistor when cold.• R1 & R6: 100k Resistor

Masking tape was used to stick the bead thermistors to the tank. Wires were soldered and insulated at the thermistors ends. A plastic box was used to house the circuit. Battery life will probably be 4 to 5 years depending on how often you use the push switch, SW1.

Thermistors NTC1-4 should be spread evenly over the height of the tank. I placed NTC1 roughly 4 inches from the top of my tank and the others were spaced evenly across the height of the hot water tank. As hot water rises the lowest sensor indicates the fullest height of hot water and should be about 8 to 10 inches from the bottom of the tank.

With a full tank of hot water adjust P1-4 so that all LED's are lit. As hot water rises, the sensor at the bottom of the tank will be the maximum level of hot water. "Hot" can be translated as 50C to 80C the presets P1-4 allow adjustment of this range.0 komentar Kirimkan Ini lewat Email BlogThis! Berbagi ke Twitter Berbagi ke Facebook Berbagi ke Google Buzz

Interface & Program LCD 2 x 16 to Microcontroller

| | Label: mikro The 2 X16 Parallel LCD is an 8 bit or 4 bit parallel interfaced LCD. This unit allows the user to display text, numerical data and custom created characters. The LCD uses the HD44780 series LCD driver from Hitachi, or equivalent controller. The LCD is connected to a female 14-pin connector for easy interface with the BS2p24/40 Demo Board (#45187) and the Professional Development Board (#28138). Though the device has the ribbon cable and 14-pin connector it may also be hooked up manually using the diagram on the next page.

The 2 X16 Parallel LCD is an 8 bit or 4 bit parallel interfaced LCD. This unit allows the user to display text, numerical data and custom created characters. The LCD uses the HD44780 series LCD driver from Hitachi, or equivalent controller. The LCD is connected to a female 14-pinconnector for easy interface with the BS2p24/40 Demo Board (#45187) and the Professional Development Board (#28138). Though the device has the ribbon cable and 14-pin connector it may also be hooked up manually using the diagram on the next page.

The following example 2x16 LCD connection (16characters, 2 line) to a dsPIC30F

microcontroller by using a 4-bit and 8-bit interface. The following code demonstrates the usage of the LCD Custom Library routines. The example covers the initialization of the LCD module and instructions for contolling and writing the module. The realization is carried out by using the mikroBasic compiler for dsPIC30F Microcontrollers. The interconnection of the LCD module and a dsPIC30F devices by using a 4-bit interface is shown in Fig. 13-1.

Interface LCD 2 x 16 to Microcontroller (dsPIC30F) using 4-bit

Interface LCD 2 x 16 to Microcontroller (dsPIC30F) using 4-bit

example program LCD 4bit

dim txt as string[15]

main:ADPCFG = $FFFFLcd_Init(PORTB, 3,2,1,0, PORTD, 0,2,1)Lcd_Cmd(LCD_CURSOR_OFF)Lcd_Cmd(LCD_CLEAR)

Lcd_Out(1, 1, "mikroElektronika")Lcd_Out(2, 1, "2x16 LCD Testing")end.

example program LCD 8bit

dim txt as string[10]

main:ADPCFG = $FFFF ' PORTB to be digitalLcd8_Init(PORTB, 7, 6, 5, 4, 3, 2, 1, 0, PORTD, 0, 1, 2)Lcd8_Cmd(LCD_CURSOR_OFF)

Lcd8_Cmd(LCD_CLEAR)

Lcd8_Out(1, 1, "mikroElektronika")Lcd8_Out(2, 1, "2x16 LCD Testing")end.

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Pengkonversi Data ADC/DAC

| | Label: mikro PCF8591

PCF8591 ialah AD/DA Converter 8 bit dengan 4 input analog menggunakan interface I2C. Chip ini sudah ramai digunakan saat ini menggantikan ADC/DAC standar seperti 0808,0809, MC1408 dan 0804. DT51 I2C ADDA merupakan Analog Input Output Add-on board untuk DT51 menggunakan teknologi I2C-bus dimana IC utama yang digunakan ialah PCF8591. I2C ADDA digunakan untuk mengubah sinyal analog seperti tegangan atau arus ke data biner dan sebaliknya. Aplikasinya antara lain kontrol kecepatan motor, pengaturan suhu ruang, akuisisi data jarak jauh dan lainnya. Pin AIN0-AIN3 ialah pin input analog, sedangkan AOUt ialah sinyal output analog.

Gambar 10.14 Susunan pin PCF8591

Gambar 10.15 merupakan rangkaian lengkap I2CADDA, dimana sebagai sumber tegangan referensi digunakan LM336 sebagai dioda zener variabel menggunakan bantuan potensiometer.

Gambar 10.15 Rangkaian I2CADDA

Untuk mencoba I2CADDA, dibutuhkan DT-51 MinSys ver.3 dan multitester, Langkah –langkah :

• Hubungkan DT-51 dengan I2C ADDA• Hubungkan output analog dengan motor DC/multitester• Masukkan program contoh adda.asm, yang akan menerima input dari AIn0-Ain3 dan

mengeluarkan data digital pada PA-PC, atau• Masukkan program contoh pembangkit sinyal gigigergaji (adda2.asm) untuk

mengeluarkan sinyal gigigergaji. Kode program ini akan anda peroleh jika memiliki kit I2CADDA.

Program Input I2CADDA (adda.asm);---------------------------------------------------------$mod51$title (DT51 I2C ADDA);input : Analog input @ Ain0-Ain3;output: Analog output from Ain0 @AOut; Digital output from AIn1 @PA; from AIn2 @PB; from AIn2 @PC;--------------------------------------------------------- CSEG

ORG 4000H LJMP Start ORG 4100H $NOLIST $INCLUDE (ADDA.ASM) $LISTDELAY: PUSH 02H PUSH 03H MOV R2, #0FFHDEL: MOV R3,#0FFH DJNZ R3, $

DJNZ R2,DEL POP 03H POP 02H RETStart: MOV P1,#0FFH MOV SP,#40H MOV Flag,#00H MOV Ch0,00H MOV Ch1,#00h MOV Ch2,00H MOV Ch3,00H ACALL DELAY MOV DPTR,#2003H MOV A,#00H MOV Mode,#0 MOV Channel,#2 SETB AutoInc LCALL InitADDA JB InitDone, NxtStep CLR P1.0 ;indikasi init gagal AJMP $NxtStep: MOV A,#00H LCALL ReadADC ;Baca Ain0-Ain3 ;Data ADC siap digunakan ;in Ch0-Ch3 MOV A,#100H ;Slave Addr=0 MOV B,Ch0 LCALL WriteDAC ;output@ AOut MOV A,Ch1 ;output Ain1 @PA MOV DPTR,#2000H MOVX @PDTR,A MOV A,Ch2 ;output Ain2 @PB MOV DPTR,#2001H MOVX @DPTR,A MOV A,Ch3 ;output Ain3 @PC

MOV DPTR,#2002H MOVX @DPTR,A AJMP $ END

Program sinyal gigigergaji(adda2.asm)$MOD51$TITLE(GENERATE SAWTOOTH SIGNAL AT Aout)

CSEG ORG 4000H LJMP Start

ORG 4100H $NOLIST $INCLUDE(ADDA.ASM) $LIST

Delay: PUSH 02H PUSH 03H MOV R3,#0FHDel: MOV R2,#0FFH DJNZ R2,$ DJNZ R3,Del POP 03H POP 02H RET

Start: MOV P1,#0FFH MOV SP,#40H MOV Flag,#00H MOV Ch0,#00H MOV Ch1,#00H MOV Ch2,#00H MOV Ch3,#00H

MOV A,#00H ;Slave Addr=0 MOV Mode,#0 ;Mode=0 MOV Channel,#0 ;Ch=0 LCALL InitADDA ;Init ADDA JB InitDone,Sawtooth CLR P1.0 ;Indicate init fail AJMP $Sawtooth: MOV B,#00H ;Data=0NxtData: MOV A,#00H ;Slave Addr=0

LCALL WriteDAC INC B AJMP NxtData AJMP $END

ADC MAX 154/158

MAXIM mengeluarkan ADC generasi baru, yaitu ADC MAX154 yang mempunyai 4 channel input dengan resolusi 8 bit, sedangkan MAX 158 mempunyai 8 channel dengan resolusi 8 bit. Chip ini sangat ringkas karena sudah tersedia sumber detak internal, bandingkan dengan ADC0808 yang membutuhkan sumber detak eksternal menggunakan TTL/kristal.

Gambar 10.16 Susunan pin MAX154/158

Pada Gambar 10.17, terlihat bahwa MAX154/158 berkomunikasi menggunakan bus alamat, data bus dan sinyal control RDY dan RD’, sedangkan CS’ diaktifkan melalui address decoder. Untuk memilih salah satu nput dari 8 input digunakan sinyal input ke A0 hingga A2.

Gambar 10.17 Contoh rangkaian berbasis MAX154/158

ADC berbasis 0808

Contoh IC ADC 8 bit yang mampu menerima 8 input dan banyak digunakan ialah ADC 0808 meskipun lebih mahal dibandingkan ADC 0804 . ADC ini selain mampu diprogram untuk mulai konversi melalui pin SC (Start Conversion ), mampu juga berjalan dalam mode free running, artinya ia akan konversi terus menerus sinyal input yang masuk dengan cara menghubungkan pin EOC (End of Conversion) ke SC.

Gambar 10.18 ADC 0808

ADC 0804ADC 0804 merupakan adc yang paling murah, karena hanya mempunyai 1 buah input analog. Rangkaian ADC melalui port paralel ini tampak pada Gambar 10.19. Hubungan ke data komputer melalui pin data yaitu D0-D7. Sinyal status yang digunakan ialah ERROR yang digunakan dengan pin 5 ADC yaitu INTR’. Dua sinyal control yaitu STROBE’ dan INIT’ digunakan untuk mengaktifkan ADC. Pin 9 sebagai Vref tidak dihubungkan. Kombinasi resistor dan kapasitor sebagai sumber detak dengan frekwensi tertentu.

Gambar 10.19 rangkaian ADC ke port parallel

Berikut program pengontrol untuk ADC tersebut menggunakan bahasa PASCAL yang dapat dengan mudah dirubah menggunakan bahasa C:

Program ADC melalui port parallel (Adcparalel.pas)const c0=1;c1=2;c2=4;c3=8;s0=1,s1=2;s2=4;s3=8; base=$378; (menggunakan LPT1)var data,stat,ctr1,eppdata :integer; sample, lc :integer;begin

data:=base;stat:=base+1;ctr1=base+2;for sample:=0 to 3000 do beginport[ctr1]:=32; (inisialisasi…)lc:=0;while (((port[stat] abd s3)=0) or lc<256)) doinc (lc);if lc>256 then write (‘time out, error pada hardware’)else beginport(ctrl):=37; (enable adc output)eppdata:=port[data];port[ctrl]:=36; (disable adc output)write (‘Hasil konversi ialah :’,eppdata);end;

end;end.

Pada program diatas, digunakan alamat standar port paralel atau yang lebih dikenal sebagai port printer yaitu 378H (dalam pascal ditulis sebagai $378). Program lalu menginisialisasi variabel untuk data, stat dan ctrl dengan nilai alamat masing masing. Program kemudian looping untuk mengambil data lalu ditampilkkan hasilnya.

PPI 8255 untuk DAC

Gambar berikut merupakan format DAC yang umum, dimana input berupa 8 bit atau lebih, dan outputnya berupa sinyal analog, yang biasanya diperoleh dari suatu rangkaian op-amp

Gambar 10.20 Blok diagram DAC standar

Ada 3 modus operasi pada PIO 8255 yang dapat dipilih melalui software yaitu :

• Mode 0 : basic input/output• Mode 1 : strobed input/output• Mode 2: bidirectional bus

Jika reset input mendapat input high, semua port akan diset ke mode input dimana semua 24 jalur ditahan pada logika 1 oleh bus internal. PPI 8255 dapat dibuat sebagai antarmuka DAC atau ADC. Untuk mencoba DAC yang terprogram paling mudah menggunakan PPI 8255 dalam mode 0. Langkah-langkah:

• Pasang Card PPI 8255 ISA, anda juga dapat menggunakan Card PPI 8255 berbasiskan PCI• Hubungkan DAC ke port A• Hubungkan keluaran DAC ke Osiloskop• Buat program berikut :

//Program Pembangkit sinyal Sinus berbasis 8255#include #include #include main(){printf (“======================”);printf (“ Pembangkit sinyal sinus\n”);

outp (0x303, 0x80); //konfigurasi 8255printf (“======================”);unsigned char v1;float Vout, magnitude; int a;printf (“\n Tekan sembarang tombol untuk keluar\n”)do{for (a=0;a<360;a++)

{Vout =5.0 +5.0* sin ((3.14*a)/180));magnitude=Vout*25.6;v1=(char)magnitude;delay(1);outp(0x300,v1)}

}while (!kbhit());return (0);}

Program diats akan membangkitkan sinyal sinus karena terdapat pembangkitan nilai sinus pada rumus Vout =5.0 +5.0* sin ((3.14*a)/180)). Alamat yang digunakan ialah 300H, yang merupakan alamat standar port ISA untuk eksperimen.