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sonicdeejay
Joined: 20 Dec 2005 Posts: 112
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Recommend me DAC... |
Posted: Sun Feb 19, 2006 9:14 am |
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Guys,,,
I am from SIngapore and I can't seem to able to source a nice DAC DIP(not surface mount)for my project.1 output channel is good enough...I already looked for MCP492x,AD5301...
I am looking for DAC with 2wire(SDA,SDL) type..I don't really want i2C DAC as I don't have a sample code...
Any DAC to recommend...
thx??
sonic
Last edited by sonicdeejay on Sun Feb 19, 2006 10:27 am; edited 1 time in total |
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drh
Joined: 12 Jul 2004 Posts: 192 Location: Hemet, California USA
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Posted: Sun Feb 19, 2006 10:20 am |
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Maxim makes DACs with the IIC interface.
www.maxim-ic.com _________________ David |
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sonicdeejay
Joined: 20 Dec 2005 Posts: 112
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Posted: Sun Feb 19, 2006 10:38 am |
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bro..possibly not i2c,,becasue I don't have a sample code,,, |
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dyeatman
Joined: 06 Sep 2003 Posts: 1924 Location: Norman, OK
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Posted: Sun Feb 19, 2006 11:30 am |
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You are ruling out I2C because no one will give you code and you don't want to try to figure it out yourself.... If I had set those kind of requirements most of my projects would have died long ago!
There is lots of code on this forum that shows how to use I2C so apparently you want someone to hand you exactly the code you want rather than put some effort into doing it yourself. Sometimes you have to bite the bullet and actually try... The process is called learning... |
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sonicdeejay
Joined: 20 Dec 2005 Posts: 112
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Posted: Sun Feb 19, 2006 11:37 am |
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sorry sir...my deadline jus too near...
![Confused](images/smiles/icon_confused.gif) |
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sonicdeejay
Joined: 20 Dec 2005 Posts: 112
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Posted: Sun Feb 19, 2006 12:34 pm |
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Please allow me to re-write my question....
I need to output 2 differents digital values (e.g temp1 and temp2) from a PIC..so I don't think i can use i2c as it only cater for 1 output....
I am using PIC18F2525...
![](http://i1.tinypic.com/o5c6ky.jpg) |
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dyeatman
Joined: 06 Sep 2003 Posts: 1924 Location: Norman, OK
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Posted: Sun Feb 19, 2006 3:32 pm |
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You CAN have multiple I2C devices on the same bus. Thats what the physical address pins on the chip and the address bits in the comm protocol are for. You need to do some reading and learn how I2C works before you dismiss it as unsuitable out of hand... Below is a link to a TI DAC device datasheet that has much of the information about I2C addressing etc...
http://focus.ti.com/docs/prod/folders/print/dac6573.html |
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Ttelmah Guest
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Posted: Sun Feb 19, 2006 3:45 pm |
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Fastest/simplest. Just use the two PWM outputs.
I2C, _does not_ just cater for one device.
The development time involved in driving an I2C device, is less than the time this thread has already been running.
You have not given enough data for anyone to really help much. What accuracy is needed?. What voltage range?. What update frequency?. etc. etc.
Seriously, sending two values this way, strikes as about the hardest/most inaccurate way possible to do this. You are going to suffer from noise, the inherent inaccuracies of both the ADC, and the DAC. etc.
I have used the MAX518 in the past, which is a dual DAC in one package. These are I2C, supporting up to four dual channel devices on one bus. The code to operate them is infantile, since they are 'receive only' devices. Just send the address, a command byte of zero for the first ADC, or one for the second, the value required, and a stop.
If you want greater accuracy, look at the MAX531. This uses SPI, and you could just add a single line with an inverter to enable one chip, and disable the other. Alternatively, using no extra lines, you can use these devices 'daisy chained', and then you can have multiple units connected in series, using no extra wires, and for twoo units just send a 32bit value, carrying the two 16bit values (12+4 dummy bits), for two devices.
Best Wishes |
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Sophi
Joined: 14 Jun 2005 Posts: 64
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Posted: Sun Feb 19, 2006 5:24 pm |
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If you really don't want to use i2C, try DAC0808. Very easy to use and cheap under $2 USD not surface mount.
*edit just saw u want 2 outputs. Sorry but DAC8080 only has one. But maybe something in its family has 2...
But I'm a total newbie and can tell you that i2C is pretty simple...CCS even has built in functions to make it happen.
SophE |
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sonicdeejay
Joined: 20 Dec 2005 Posts: 112
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Posted: Sun Feb 19, 2006 7:45 pm |
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Ttelmah wrote: | Fastest/simplest. Just use the two PWM outputs.
I2C, _does not_ just cater for one device.
The development time involved in driving an I2C device, is less than the time this thread has already been running.
You have not given enough data for anyone to really help much. What accuracy is needed?. What voltage range?. What update frequency?. etc. etc.
Seriously, sending two values this way, strikes as about the hardest/most inaccurate way possible to do this. You are going to suffer from noise, the inherent inaccuracies of both the ADC, and the DAC. etc.
I have used the MAX518 in the past, which is a dual DAC in one package. These are I2C, supporting up to four dual channel devices on one bus. The code to operate them is infantile, since they are 'receive only' devices. Just send the address, a command byte of zero for the first ADC, or one for the second, the value required, and a stop.
If you want greater accuracy, look at the MAX531. This uses SPI, and you could just add a single line with an inverter to enable one chip, and disable the other. Alternatively, using no extra lines, you can use these devices 'daisy chained', and then you can have multiple units connected in series, using no extra wires, and for twoo units just send a 32bit value, carrying the two 16bit values (12+4 dummy bits), for two devices.
Best Wishes |
I am sending a value 0~5V from PIC1 to PIC2....as for accuarcy...the more the better...
If I am to use PWM,,I have no idea..how I can generate PWm represent the wave to raning from 0-5V and from the receiver how to interpreted as well... |
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sonicdeejay
Joined: 20 Dec 2005 Posts: 112
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Posted: Sun Feb 19, 2006 7:59 pm |
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dyeatman wrote: | You CAN have multiple I2C devices on the same bus. Thats what the physical address pins on the chip and the address bits in the comm protocol are for. You need to do some reading and learn how I2C works before you dismiss it as unsuitable out of hand... Below is a link to a TI DAC device datasheet that has much of the information about I2C addressing etc...
http://focus.ti.com/docs/prod/folders/print/dac6573.html |
thx for the help...Sir...
Seem lik they are only avail in surface mount... ![Sad](images/smiles/icon_sad.gif) |
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Charlie U
Joined: 09 Sep 2003 Posts: 183 Location: Somewhere under water in the Great Lakes
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Posted: Sun Feb 19, 2006 8:18 pm |
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There must be 10's if not 100's of different DACs with SPI and in a DIP package. It took me about 30 seconds to find a TI part: TLC5615.
http://focus.ti.com/docs/prod/folders/print/tlc5615.html
Try this one for a start.
Also try National, Linear Tech, Analog Devices, etc. |
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sonicdeejay
Joined: 20 Dec 2005 Posts: 112
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Posted: Sun Feb 19, 2006 8:27 pm |
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Charlie U wrote: | There must be 10's if not 100's of different DACs with SPI and in a DIP package. It took me about 30 seconds to find a TI part: TLC5615.
http://focus.ti.com/docs/prod/folders/print/tlc5615.html
Try this one for a start.
Also try National, Linear Tech, Analog Devices, etc. |
aren't we looking @ i2C currenly,,,,
Anyway I jus got myself AD5311 http://www.analog.com/en/prod/0,,AD5311,00.html
any idea...it will suit my need?? ![Smile](images/smiles/icon_smile.gif) |
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Charlie U
Joined: 09 Sep 2003 Posts: 183 Location: Somewhere under water in the Great Lakes
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Posted: Sun Feb 19, 2006 9:06 pm |
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I have no idea if this will suit your needs, because your original needs were a DAC in a DIP with SPI, now you have selected a DAC that is only available in SMT (MSOP and SOT23) and has an I2C interface. What exactly are your needs? |
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newguy
Joined: 24 Jun 2004 Posts: 1903
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Posted: Sun Feb 19, 2006 10:21 pm |
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Charlie U wrote: | I have no idea if this will suit your needs, because your original needs were a DAC in a DIP with SPI, now you have selected a DAC that is only available in SMT (MSOP and SOT23) and has an I2C interface. What exactly are your needs? |
From what I've been able to gather, his needs are to get someone to do his homework for him. |
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