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This demo provides an example on how to use the communication interface provided in the modules firmware,
to setup the pre-amplification and trigger an ADC measurement.
The module saves after a trigger event 1 million samples of ADC measurement in its SDRAM.
Those values are gathered in parts of 16 kbytes and converted from RAW ADC data to standard integers and
floating point numbers.

The signal is plotted, showing its value over time, and Fourier transformed, showing its frequency spectrum.

The user can easily access the pre-amplification and the length of the processed and plotted part of the data
through a GUI.

Communicating with module:

To communicate with the module, a serial comport port with a speed set to 115200 bits needs to be opened.
Commands consists of a single character in UTF-8 encoding.
It is good practice to communication with the module following these steps:

  • Open a serial comport
  • Clear the PCs serial comport input buffer of the opened comport
  • Send the desired commands, each one in a single write operation to the comport
  • Close the serial comport as soon as possible

These steps apply also for read operations.

Using the ADC for high speed consecutive measurements

The module provides a method to gather highly accurate consecutive ADC measurements in a single event.
In this mode of operation, one mega sample of ADC values are performed and stored inside the modules

The following step should be taken in this mode:

  • Open a serial comport
  • Send the command "1", "2", "4" or "8" for the ADC pre-amplification
  • Send the command "t" to trigger the consecutive measurement.
    (The module always measures 1 MSample of data into its SD-RAM)
  • Clear the PCs serial comport input buffer of the opened comport
  • Send the command "+" or "*"to the module, it then transmits 128 or 16384 Samples of ADC values
  • Read the amount of ADC values in one chunk of 128 or 16384 samples from the PCs serial input buffer
    (Otherwise there is a high possibility of a misalignment of nibbles)
  • Repeat the reading of chunks to a maximum of 1 mega sample
  • Close the comport

After a trigger event, the one mega sample of data is stored until your retrigger. So processing the data can
be done for each chunk individually or the whole one mega sample.

Information to convert the RAW ADC data into standard integer values.

Module TEI0015 - AD4003BCPZ-RL7

Resolution: 18-bit / 5 nibbles
Maximum sampling rate: 2 MSPS

Order of Values:

Mid scale0x000000

Positive 1 LSB0x000011to full scale -1 LSB0x1ffff131071
Negative full scale0x20000131072to -1 LSB0x3FFFF262143

The layout of the ADC circuit is further described in the Analog Devices circuit note CN-0385.

Module TEI0016 - ADAQ7988 / ADAQ7980

Resolution: 16-bit / 4 nibbles
Maximum sampling rate: 0.5 MSps / 1 MSps

Order of Values:

Negative full scale is0x00000to -1 LSB0x7fff32767
Mid scale is0x8000 32768

Positive 1 LSB0x800132769to full scale0xffff65536

The layout of the ADC circuit is further described in the Analog Devices circuit note CN-0393.

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