Analog Discovery board as Data Acquistion board

[AbdulWaheed46]

Hello,

 

I have recently got my hands on Analog Discovery 3. I want to use it as a data acquisition system. I want to capture data from it at 40 MSPS and a resolution of 16 bits. I am just sending a high low signal from Arduino. I see that the waveforms software shows that the device is capturing 32786 samples at 100 MHz, but when I check the samples from one high to another high it is just 838 samples. which is not even 1 MSPS. I want to capture he data at 40MSPS. I am not sure, where am I even going wrong.

Any help will be greatly appreciated.

[JColvin]

Hi @AbdulWaheed46,

How fast is the signal being toggled from the Arduino? Can you share a screenshot?

If you have a single Analog input channel enabled on the default configuration, the most samples you can get per acquisition (i.e. the buffer size) is 32768 samples, which you noted and as is also mentioned in the Horizontal System for the Analog Input Specifications: https://digilent.com/reference/test-and-measurement/analog-discovery-3/specifications#analog_input_channels). I am mentioning this first because the buffer size per acquisition is a fixed value.

The sample size will then dictate how large of a "slice" of time you can view/capture at different sample rates. At 100 MHz (aka, a new sample every 10 ns), the 32768 sample buffer size only allows you to view a time slice of up to 327.68 us, or correspondingly, a time base of 32.768 us/div.

If you are zoomed out to a wider time scale, you would have empty space on either side of the 327.68 us block of data that was captured at 100 MHz before the buffer was filled. To help with this, WaveForms will automatically adjust the time base / sample rate when the other value is changed so that the acquired data is always taking up the entire view plot.

Let me know if you have any questions.

Thanks,
JColvin