ADC0804 Pinout and Typical Connections

As shown in the typical circuit, ADC0804 can be interfaced with any microcontroller. You need a minimum of 11 pins to interface ADC0804, eight for data pins and 3 for control pins. As shown in the typical circuit the chip select pin can be made low if you are not using the microcontroller port for any other peripheral (multiplexing).

ADC0804 connection with microcontroller

There is a universal rule to find out how to use an IC. All you need is the datasheet of the IC you are working with and take a look at the timing diagram of the IC which shows how to send the data, which signal to assert and at what time the signal should be made high or low etc.

Note: Keep this in mind that whenever you are working with an IC and you want to know how to communicate with that IC, then simply look into the timing diagram of that IC from its datasheet. It gives you complete information that you need regarding the communication of IC.

ADC0804 Timing diagram - start of conversion
ADC0804 Timing diagram - reading ADC output

The above timing diagrams are from ADC0804 datasheet. The first diagram (FIGURE 10A) shows how to start a conversion. Also you can see which signals are to be asserted and at what time to start a conversion. So looking into the timing diagram FIGURE 10A. We note down the steps or say the order in which signals are to be asserted to start a conversion of ADC. As we have decided to make Chip select pin as low so we need not to bother about the CS signal in the timing diagram. Below steps are for starting an ADC conversion. I am also including CS signal to give you a clear picture. While programming we will not use this signal.

  1. Make chip select (CS) signal low.
  2. Make write (WR) signal low.
  3. Make chip select (CS) high.
  4. Wait for INTR pin to go low (means conversion ends).

Once the conversion in ADC is done, the data is available in the output latch of the ADC. Looking at the FIGURE 10B which shows the timing diagram of how to read the converted value from the output latch of the ADC. Data of the new conversion is only avalable for reading after ADC0804 made INTR pin low or say when the conversion is over. Below are the stepts to read output from the ADC0804.

  1. Make chip select (CS) pin low.
  2. Make read (RD) signal low.
  3. Read the data from port where ADC is connected.
  4. Make read (RD) signal high.
  5. Make chip select (CS) high.


In the next section of this tutorial we will follow the above mentioned steps to program the ADC.

Conversation

ExperimenterUK
Thu Oct 30 2014, 06:02 PM
This is a chat box..create a thread if you need help...but we don't do homework
Tue Oct 28 2014, 07:33 PM
vinni
hi rickey...anyone got the pgm...pls gimme now
Tue Oct 28 2014, 06:35 PM
potla
hi vinni even i need that program. help me if you get it
Tue Oct 28 2014, 03:22 PM
vinni
1. Using a look-up table in Flash ROM and accumulator offset indexed addressing mode, write a program that acts as a timer. The timer should count from 0 to 59 seconds. After reaching 59, it should go back to 0 on the next second and continue to count up. The timer should use the seven-segment display. The look-up table should contain information on how to display the digits 0 – 9 on the seven-segment display
Tue Oct 28 2014, 03:22 PM
vinni
hello Rickey..i need this pgm very urgently
Tue Oct 28 2014, 01:42 AM
Boy Donald
Dear sir, thanks before. i have some project urgent for my school and my project need this digital countdown timer using 7 segmen display. but your project only show ten minutes countdown, i need your help, can you show me more to change the minute or set the time manually. thank you, sorry for disturbing you.
Tue Oct 28 2014, 01:32 AM
Boy Donald
dear sir
Tue Oct 28 2014, 01:19 AM
Boy Donald
Rickey you inspired me a lot but why i can not change the time ( minute
Sun Oct 26 2014, 02:51 AM
sandeep bankar
dear sir I m facing problem about..how to read number of incoming call in gsm 900 a. pls help how to read it in atmel avr microcontroller.
ajay_bhargav
Mon Oct 20 2014, 11:22 AM
@skrishna, please post in forum so we can help you better.

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sanospsa
Fri Oct 31 2014, 09:23 AM
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Thu Oct 23 2014, 04:18 PM
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Sun Oct 19 2014, 01:56 PM
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Thu Oct 16 2014, 08:48 AM
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Tue Oct 14 2014, 06:23 PM

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Fri Oct 31 2014, 01:44 AM
Hi Ajay, I wanted to know can we use transformer ...
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Posted By Max.otto
Thu Oct 30 2014, 11:09 AM
Hello all, before generating i have to give PWM p...
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Posted By prash5054
Thu Oct 30 2014, 06:40 AM
can u post the updated code for the above problem ...
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Thank you for the feedback.It's good to hear when ...
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ExperimenterUK: Thankyou so much for helping me......
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thanks ExperimenterUK for your help.... I will try...
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Your error seems to be the use of PINC, which is f...
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