petert1
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DAC for 0 - 10v output

Sun Dec 22, 2013 10:55 pm

Hi,
Anybody have Pi experience with a DAC which can output 0 to 10V .?
Input from either I2C or SPI.
Python preferred
Any suggestions appreciated. Tutorials very welcome!

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Richard-TX
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Re: DAC for 0 - 10v output

Mon Dec 23, 2013 2:43 pm

I can find no DACs with a V_out like you specified. Having said that, there is a way to achieve what you want. See the application note at http://www.maximintegrated.com/app-note ... mvp/id/429

So for a complete solution you will need 2 DACs. One to control the gain of the amplifier and the other to do the D-A conversion.

It really is a nice solution as the PGA can be trimmed to some very good accuracy.


Richard
Richard
Doing Unix since 1985.
The 9-25-2013 image of Wheezy can be found at:
http://downloads.raspberrypi.org/raspbian/images/raspbian-2013-09-27/2013-09-25-wheezy-raspbian.zip

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Richard-TX
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Re: DAC for 0 - 10v output

Mon Dec 23, 2013 2:52 pm

If you are starting out with data conversion, I would look at the DAC/ADC boards being sold on Ebay. For less than $2 delivered, the 4 channel adc with single channel DAC is a great learning tool. It uses the PCF8591 chip. There is tons of example code out there for it.

http://www.ebay.com/itm/190888152989
Richard
Doing Unix since 1985.
The 9-25-2013 image of Wheezy can be found at:
http://downloads.raspberrypi.org/raspbian/images/raspbian-2013-09-27/2013-09-25-wheezy-raspbian.zip

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mahjongg
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Re: DAC for 0 - 10v output

Mon Dec 23, 2013 3:42 pm

DAC with 0..5V output plus 2x gain Opamp

use a 12V powered rail-to rail and single power supply capable opamp.

petert1
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Joined: Sun Dec 22, 2013 10:28 pm

Re: DAC for 0 - 10v output

Mon Dec 23, 2013 7:13 pm

Thanks to all. Those are good suggestions- I think I'll try them all.. Will let you know results.

:D

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Richard-TX
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Re: DAC for 0 - 10v output

Tue Dec 24, 2013 1:52 am

mahjongg wrote:DAC with 0..5V output plus 2x gain Opamp

use a 12V powered rail-to rail and single power supply capable opamp.
That is exactly what that application note defines except that the gain of the opamp is programmable.
Richard
Doing Unix since 1985.
The 9-25-2013 image of Wheezy can be found at:
http://downloads.raspberrypi.org/raspbian/images/raspbian-2013-09-27/2013-09-25-wheezy-raspbian.zip

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mahjongg
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Re: DAC for 0 - 10v output

Tue Dec 24, 2013 1:59 am

the gain can obviously be set by choosing the feedback resistors, but a times 2 gain transfers a 5V max output to a 10V max output, like you wanted.

if you use this circuit for the opamp:
Image
it will have a gain of 2 if both R1 and R2 are the same (10K typically).

Bruce_Pi
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Joined: Tue Feb 21, 2017 5:09 pm

Re: DAC for 0 - 10v output

Mon Apr 30, 2018 4:55 pm

@natopal46 the i2c chip you mentioned is digital IO expander NOT a DAC. To get a analog output you will need to use a DAC not io. there aren't many DAC chips which outputs 0-10V, most of these outputs 0-5V. You will need build a amplifier with gain set to two.
If you are not sure how to build or dont have tools i will recommend getting a breakout board which already has all this on board.
something like this 0-10V i2C DAC https://store.ncd.io/product/1-channel- ... -i%C2%B2c/

Cheers!!!

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Aptinex
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Re: DAC for 0 - 10v output

Fri Sep 28, 2018 4:06 pm

You can use Aptinex DAC Module DA1C010BI I2C Digital to Analog 0-10V which is base on MCP4725 dac.
Image
https://aptinex.com/product/aptinex-dac ... p4725-i2c/
Aptinex (Pvt) LTD.
No 167 1/1, Galle road,
Dehiwala,
Sri Lanka

info@aptinex.com
+94 11 2735220

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