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Topic: High speed read of bipolar signal, -> ADC (LTC1605) (Read 2 times) previous topic - next topic

SuperR

I think 10bit resolution is fine. However, I have both positive and negative voltages. If it helps to use an external ADC and DAC, I think that's possible. And DC42, nice to know that code can be run while I wait for the ADC is running. I'll investigate further within the next couple weeks.

michinyon

I don't understand how you plan to have output to an accelerometer.

SuperR

From an accelerometer, not to. The accelerometer is my sensor

SuperR

I have been informed of the Arduino Due, which might solve my speed-problems. An order is pending so I should be up and running shortly. More to come :)

SuperR

#9
Feb 24, 2013, 09:06 am Last Edit: Feb 24, 2013, 11:21 am by SuperR Reason: 1
Ok, there's an update on the situation;

Instead of using the analogread or shaping the analog signals so that they fit the requirements of the Arduino Due internal adc, I am going to implement a dedicated ADC. The one available at the lab is a LTC1605. Just the IC, I need to built a PCB so I am free to implement different/extra IC's.

http://cds.linear.com/docs/en/datasheet/1605fc.pdf

Therefore, the questions now turns into;
What is the fastest/best way to turn those 16 output pins of the IC into a value in my Arduino Due? And even worse, I would read two of these ADC's.

After studying the spec sheet my steps would be;
Put CS low, (initiate conversion of ADC)
Wait 8 uS, time it takes between CS low and valid data
Read 1 byte, (8 I/O pins) from ADC1
Read 1 byte, (8 different I/O pins), from ADC2
Put "Byte" high,
Read second byte from ADC1
Read second byte from ADC2

That would cost me around 20 pins for 2ADC's, leaving me plenty pins for the DAC, which uses around 20 too.



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