interfacing 8051 with adc

You probably need to be a lot more specific as to what your project is going to be, what your intending to sample with the ADC, resolution you hope to attain and the sample rate that will be required. On the RF side we have no idea what you think the RF would be expected to be for. For all we know you hope to have the microcontroller enter into communications with your microwave oven.

- mkaras

If about 8 bits is good enough, look at

and pick the one that does what you need. Beware that because they are on the same ship as the micro, they are noisy.

If you need better, go to

and look at the ADCs they offer. Some interface like external memory and others use a serial connection. For the serial ones, you need to step through the timing diagram with code. Fortunately, in the 8051 this is very easy to do.

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kensmith@rahul.net   forging knowledge

Hey Gautham,

Please be more specific. I see that you want to interface an ADC. But unless you are completely aware of the signal characteristics you want to digitize, it would be extremely difficult to comment on the design part of it.

It is my understanding that you want to convert the Analog data and transmit it through some RF transceiver

Well first find out the signal data characteristics. Determine the resolution required. It is quite possible that the Microcontroller you choose may have an inbuilt ADC (on chip). If you need a higher resolution, you may have to use some other ADC.

About the RF part, you have find out the characteristics of the Transceiver then determine how you have to design that part of the interface.

Good luck in your design. Bye

avr are easy to use/program.

SFC

"gautham" schreef in bericht news: snipped-for-privacy@s80g2000cwa.googlegroups.com...

well,to be more specific,the data input to the microcontroller comes from a 220v, 50Hz power line,representing the power flow,voltage etc.this analog data is interfaced with the microcontroller with an adc.the frequency of the signal being less,any frequency on the upward of 1MHz would work very fine.the resolution that i want is in the order of a few hundred millivolt.therefore,i am planning to use a 14 bit adc.my question is regarding the hardware interfacing of this adc with the microcontroller. for example,how do i tune the microcontroller to the frequency of the adc?would the results be accurate?the rf segment is to connect the microcontrolller wireless to a remote host computer, where detailed analysis of the data would be done.

Hi Gautham, Now in most of the microcontrollers, you sure to find not one, but two or three ADCs with average of 14 to 16 bit resolution. Have a look at this report where latest microcontrollers are listed with some specs. Here is the link

EMITT Solutions also can provide a list of RF trasceivers provided you give exact specifications. Check with in case you need short range RF transceivers.

Atmel is fine for 8051 based MCUs. If your MCU need to handle more of Audio and Video than go for RISC based.

Srinivasa Reddy N. EMITT Solutions

Hi Gowtham,

Let me get this correctly. You actually want to connect the 220V 50 Hz mains (AC) to the ADC and digitize it. Is that what you want to do?(pl confirm)

Well, I have not come across an application like that. But I dont think there is a ADC which can directly accept that kind of voltage (220v).

There should be some kind of scaling system in between. If that becomes the case, I dont see how a 14 bit ADC will help. The margin of error may be quite large (due to scaling sys).

Regards.

The first step is to select an ADC that suits your task, and is easy to interface. I've used ADCs and DACs that communicate with the 8051 using SPI bus. I did the SPI communications using "manual bit-banging", but there may be some 8051 (or other micro) versions with a SPI interface.

Depending on the accuracy you need, you may want a voltage reference IC to provide the reference voltage for the ADC - but some ADCs have an internal reference.