Does anyone know of a 12-bit DAC with code on the Propeller Object Exchange.

donnpangy

Does anyone know of a 12-bit DAC with code on the Propeller Object Exchange. The 8-bit DAC is not going to be enough resolution for my project. I am new to spin and Prop assembly, and I am looking for code that might do this.·How complicated work it be to change Chip's MCP3208·SPI ADC code to DAC SPI code?·
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I googled SPI and DAC and found these chips that might work.
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MCP4921/4922·· 12-Bit DAC with SPI™ Interface......................................................................$3.14 at Digiket.com
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AD5025: ·Fully Accurate 12-Bit V_OUT DAC SPI Interface 2.7 V to 5.5 V in a TSSOP..........................$5.21 at Digikey.com

DAC124S085 - 12-Bit Micro Power QUAD Digital-to-Analog Converter·................$6.20 at Digikey.com
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thanks for any ideas,
Don
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Timmoore

I dont remember whether I ever posted this but this is for the mcp4705 dac. Its a 12bit dac.

SRLM

There is some code posted for the MCP3208 12 bit ADC here: obex.parallax.com/objects/search/?q=MCP3208

As a side benefit, Parallax sells the modules (2, 4 and 8 channels). I also have a version with some magic smoke that automatically samples data. Let me know if you want to use it.

donnpangy

Tim,
··· Thanks so much for the info, and your code looks very easy to follow. I am actually going to need 8 DAC's in this project, and it looks like your chip will support 8 DAC chips on 2 lines.

··· Is there an easy way to interface the Prop pins at 3.3v to the DAC running around 5v to 6v?



thanks again,
Don

Timmoore

You probably dont want to run the dac much more than 5V, its max is 5.5V. To interface the prop to 5V I2C devices I normally use on the SDA and SCL lines a 1K inline resistor and a 4.7K pull up to 5V on the device side of the 1K resistor
i.e. prop pin 28 to 1K, 1K to device. 4.7K from device to +5V, same for prop pin 29

donnpangy

Thanks Tim,

··· Parts are on order and I should have it running end of next week.

thanks again,