How to convert digital to analog

@shahrul-Ex12xz • May 14, 2009

Rifaa
I think you are really confused, cause I really donno what you just said.

Which part you don't understand?

and as for I2C, it's really complicated communication method developed by Sony and Philips.
it uses 2 lines and communicate serially to slave devices.
Before programming a PIC, you should study the I2C communication method thoroughly

I ask about IC that convert I2C to analog. Ofcourse I need to program that, but must have the device first.

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@rifaa-NaWZZ4 • May 14, 2009

I2C bus is used mainly in Sony and Philips equipments. This technic is not based on a single IC, it's rather a communication method that a lot of LSI chips uses to communicate.
And it's a very reliable method too, one can add any number of slave devices. You just need to address the slave device before command is given.
I2C cannot be converted to analog since it is not a PWM signal. But it consists of a serial clock together with a serial data that works together. So you cannot just use I2C just like that. Sony and Philips have devoloped codes for their LSI devices in order to address them.
Get my point

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@shahrul-Ex12xz • May 14, 2009

Rifaa
I2C cannot be converted to analog since it is not a PWM signal.

There have a DAC with I2C interface. So, I can communicate my PIC with 2 I/O to convert into analog.

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@rifaa-NaWZZ4 • May 15, 2009

I2C is a command signal and there for what's the point. It's not just an analogue voltage.
It contains the information with which two LSI communicate.
What part of this you do not understand?

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@rifaa-NaWZZ4 • May 15, 2009

What you want is useless and may not even be possible.

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@shahrul-Ex12xz • May 15, 2009

Rifaa
What you want is useless and may not even be possible.

I think, you are messy here. Ofcourse, I2C not the voltage, but the digital signal that needs to convert to analog. That's why called 'Digital to Analog Converter'. Look this ex IC, <a href="https://pdf1.alldatasheet.com/datasheet-pdf/view/90568/TI/DAC6574.html" target="_blank" rel="nofollow noopener noreferrer">DAC6574 pdf, DAC6574 Description, DAC6574 Datasheet, DAC6574 view ::: ALLDATASHEET :::</a>. This IC convert digital to analog with interface by I2C.

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@rifaa-NaWZZ4 • May 15, 2009

Look, I know what DAC's and ADC's are but you cannot change the I2C bus to an analogue voltage no matter what you do, cause it is just pulses, not PWM. It's either at 5V or 3.3V.
So you go ahead, be the clever one and show me.
Besides what does an electrical engineer will do with LSI communication technics. U need to know what SCL and SDL are and it's timing.

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@shahrul-Ex12xz • May 15, 2009

Rifaa
Look, I know what DAC's and ADC's are but you cannot change the I2C bus to an analogue voltage no matter what you do, cause it is just pulses, not PWM. It's either at 5V or 3.3V.
So you go ahead, be the clever one and show me.
Besides what does an electrical engineer will do with LSI communication technics. U need to know what SCL and SDL are and it's timing.

I just gave you the DAC, it's use I2C. That is the interface.

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reachrkata

@reachrkata-FOcqhH • May 15, 2009

Woah Woah there !!! Calm down !!

With all due respect to Rifaa, I think what Shahrul says is perfectly possible. Though I2C protocol as such is bits, the data that it transfers to the IC can indicate what analog voltage the IC should output.

-Karthik
😁

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@rifaa-NaWZZ4 • May 15, 2009

I'm not mad guys. This is one argument none of you will win, since I know what I2C protocol is and I deal with it almost every day than any other CEans, this I can guarantee
What I am saying is changing I2C to analog won't do u any good since it is a communication signal and is bidirectional.
I2C interface is there to communicate with in the LSI platform, it will be of no use in analogue form.
Yes, you can use I2C to communicate through PIC's, but you have to use the PIC's IO ports to interface with any actuators and indicators, etc. It is not the I2C tht you are changing to analogue via PIC's IO ports. But rather you use it to tell the slave IC's what to do and they can reply in return.

And further more if you want to use I2C protocol then I suggest you to get your hands on the codes they use for their LSI chips.

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@harshad-ukH5ww • May 15, 2009

Yep I am with Rifaa..

I2C is a protocol in which you have to give Device and many more than and then it works... as said by Rifaa it is bidirectional and gives output data according to request..

so as per my knowledge it is not proper way to convert your digital voltage to Analog.

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@rifaa-NaWZZ4 • May 15, 2009

Aaaaaah! At least there is one CE that is not crazy ;-) ( get me )

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@shahrul-Ex12xz • May 15, 2009

Look that DAC6574. The output is quad analog voltage. The input is 10bits digital. The digital comes from I2C interface. So, the I2C will represents the analog output. What the impossible here? Why not we think crazy to make crazy thing?

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@harshad-ukH5ww • May 15, 2009

We think Crazy dude... lets give it a try Ok...

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@harshad-ukH5ww • May 15, 2009

Shahrul.... i have one Question if you are going to Connect DAC6574 with I2C then DAC6574 will work as a slave right? so you want to use DAC6574 as a Slave? or just want want to convert the 2 line (as per the I2C protocol) analog into the Digital Voltage.

Lets do practical on this see what happens..!!

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@shahrul-Ex12xz • May 15, 2009

My task, I want to develop many analog output from single PIC based on other condition. I'm not using the DAC6574 yet. Based to the datasheet, it produce 4 analog output. It controlled by the I2C interface. I will use this as slave and PIC as the master.
The I2C surely the signal, and the analog output must comes from the VCC.

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@harshad-ukH5ww • May 15, 2009

Yes then lets give it a try so we can get atleast conclusion

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@shahrul-Ex12xz • May 16, 2009

Yes, I'm going to do this. That's why I ask for other experience/opinion.

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@rifaa-NaWZZ4 • May 16, 2009

U guys are crazy alright, but remember to give a serial data to be converted in to analog via SCL and SDA
and address the device via A0 and A1 to enable it , it should be in I2C.......I2C....... I2C....... I2C....... I2C....... I2C....... I2C....... I2C....... I2C....... I2C....... I2C....... I2C....... I2C....... I2C....... I2C....... I2C....... I2C....... I2C....... I2C....... I2C....... I2C....... I2C.......
GET THE POINT. Crazy Crazy pple. Pls READ THE DATA SHEET PROPERLY.
TOLD YA YOU CANNOT WIN OVER THIS 😎

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@Ash • May 16, 2009

Rifaa, whats up with you? 😛 This isnt about winning an argument, its about trying to find a solution. You have been adamant about this direct I[sup]2[/sup]C signal to analog issue. We are not discussing about that. Some of your posts did not need to antagonize that poor fella.

All Shahrul wants to do is convert the serial digital data into analog via an interface. He already has a master PIC with I[sup]2[/sup]C communications and wants to use a DAC as slave. We know that the serial communications needed to reach the interface is I[sup]2[/sup]C via the SDA (data) and SCL (clock) lines.

The focus now is what code to use in the PIC. You basically need the correct addressing byte and clock speed. The address byte will determine which DAC and output analog pin will be chosen. All of that is in the datasheet. Once that is done, you keep on looping the data (amounts of bits depend on DAC type).

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@rifaa-NaWZZ4 • May 16, 2009

hey Ash.. chill out. This is a friendly argument over converting I2C to analogue, I just told before it cannot be done, and he denies it, now you see it is not the I2C that is being converted. Simple.
He can convert whatever data he wants through SDA input, I think I have made my point.
The point is what he stated at first and I respect fully said otherwise.
And what he is doing is what exactly I said the PIC would be used for concerning I2C, even you agreed on it.
So, like I said he can be crazy enuf to try it, I did not say not to, just that he can't use I2C in analogue form
Peace guys.
Rifaa

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@Ash • May 16, 2009

Rifaa, I think its a simple misunderstanding 😀 Here is his first three posts regarding the matter:

shahrul
Hi,
I want to produce many analog output from a single PIC. Normally 1 channel analog output need 8 digital output from PIC (using DAC). How I want reduce the output, let say use I2C to Analog or PWM to Analog. What is the device/IC and how the performance (in term of analog sampling).

Highlighted red and bold was his question. By performance he means how fast can the DAC operate from converting the input data bits to the output voltage signal.

shahrul
I ask about IC that convert I2C to analog. Ofcourse I need to program that, but must have the device first.

Again, he is talking about the DAC which will be used as the slave device.

shahrul
There have a DAC with I2C interface. So, I can communicate my PIC with 2 I/O to convert into analog.

Even after this Rifaa, you still thought he was talking about using the I[sup]2[/sup]C as an analog signal, when we clearly stated from the beginning that he wanted to use a DAC IC device to convert from digital to analog.

It was certainly not a friendly argument if you totally misunderstood his query 😉 You assumed he did know anything about using that interface. All he wants is the DAC device with I[sup]2[/sup]C capabilities and how to program it 😀

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@rifaa-NaWZZ4 • May 16, 2009

I did not assume anything and I did not argue. I just proved my point. that's all.
Besides I just asked him what does an electrical engineer got to do with I2C, and what ever he wants, he can't use the I2C by converting it to analogue.
What he knows and how good he is does not really matter to me. I couldn't care less

Originally Posted by shahrul #-Link-Snipped-#
I ask about IC that convert I2C to analog. Ofcourse I need to program that, but must have the device first.
All I wanted to tell him was that I2C is not a signal that can be used to input a DAC, but rather I2C is a communication bus that addresses LSI.
Whatever the DAC receivers it will convert to analogue, but it is not the I2C that is being converted but the serial data.

So Ash I think you are confused too. 😁

Hey Shahrul, I did not judge you or think of arguing with you and be little you or anything OK, cause I am not that kind.
You must be good at what you do. I just thought what the heck does I2C and electrical will do. u know.
all I see is in TV's, LCD's and Hi-Fi's have this I2C, but not in an generator or power grid. u know what I am saying

Any ways, It's over. so tell me what is the project that this dude is going to make, or what is he planning, by using I2C PIC's.
If any thing concerns PIC's, I like to be in it.

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@shahrul-Ex12xz • May 16, 2009

Rifaa, you misunderstood the statement.
You defence your statement that "I2C cannot convert into analog". Ofcourse, I2C is the interface, the data that feed to the DAC. The analog output not exactly comes from the I2C. It comes from the VCC.

Rifaa
all I see is in TV's, LCD's and Hi-Fi's have this I2C, but not in an generator or power grid. u know what I am saying

We know, the I2C is digital signal. I'm not thinking to use I2C to generates power.

Rifaa
Any ways, It's over. so tell me what is the project that this dude is going to make, or what is he planning, by using I2C PIC's.
If any thing concerns PIC's, I like to be in it.

Ok, I'm over. But the main discussion here not answered yet. About the performance.

If I use parallel signal, ofcourse I can get better sampling analog output. I don't know how I2C performance yet.

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@rifaa-NaWZZ4 • May 16, 2009

I remember having an I2C protocol document. I have to search my old database.
It can give you a very through insight on how I2C operates.
Do you want it?

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@shahrul-Ex12xz • May 17, 2009

Rifaa
I remember having an I2C protocol document. I have to search my old database.
It can give you a very through insight on how I2C operates.
Do you want it?

Ofcourse, you can attached related file. I'm happy to hear your experience because I like practically rather than theoretical.

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@rifaa-NaWZZ4 • May 17, 2009

Great ! Looking for it

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@rifaa-NaWZZ4 • May 17, 2009

Here's the first one

#-Link-Snipped-#

and also the addressing data

#-Link-Snipped-#

Enjoy

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@Ash • May 17, 2009

Haha, whether I ended up confused or not, I'm glad everyone is back on the same page 😛

If one is using I[sup]2[/sup]C with a PIC, you can expect max speeds of 400kbps.. if the DAC also supports that mode, that is.

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@shahrul-Ex12xz • May 17, 2009

ash
If one is using I[sup]2[/sup]C with a PIC, you can expect max speeds of 400kbps.. if the DAC also supports that mode, that is.

The DAC can support I2C up to 3.4Mbps. It should not a problem. Thanks to Rifaa for the supported documents.

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@rifaa-NaWZZ4 • May 17, 2009

Any time, do update the post on the progress of this task.

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@shahrul-Ex12xz • May 31, 2009

I'm changing the IC from DAC6574 into AD7808, because I cannot find the DAC6574 in my area. The AD7808 using SPI mode. I'm working for this now.

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@Ash • May 31, 2009

Wheres your area by the way?

Be careful not to use a high speed SPI rate. Data can get corrupted.

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@shahrul-Ex12xz • May 31, 2009

ash
Wheres your area by the way?

Be careful not to use a high speed SPI rate. Data can get corrupted.

The I2C DAC not available at the Pasar Road, then I'm searching at Farnell Mas..
Thanks for your advice, normally for first try, begin with low speed first.

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urgull

@urgull-Rx9nsn • Jun 11, 2009

Digital-to-analogue conversion is much simpler to achieve than analogue-to-digital conversion and the cost of building the necessary hardware circuit is considerably less. for futher detail information visit this
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for interfacing point of veiw you can go here
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