TT063: Stubbs Thermistor DAQ

7-channel data acquisition system for hot-wire anemometer for Stubbs lab, using ToprADS8684 board on a TipTop1590G base.  Power is 12V at <200mA.

ToprADS8684 board has a buffered excitation voltage output, currently set to 4.096V, but Stubbs researchers don't plan to use it.

The ADS8684/8 has software-programable input ranges from +/-2.5V to +/-10V bipolar and 0-5V to 0-10V unipolar.

Top view:

Note that this is the 4-channel versions – only components for channels 0-3 are installed.  The 7-channel version uses all channels except channel 4.

Inside view:

Pretty typical.  Isolated USB.  12V input goes up to the Topper.

Bottom view of ToprADS8684:

This is the 4-channel board.  The 7-channel version changes the ADS8684 to the 8688 and adds the input filters of the new channels.

Marked-up schematics of ToprADS8684:

Complete CAD files are in the Tiptone/boards subdirectory.

Arduino code acquires 7 channels at 1 KHz and sends it out USB comms port in CSV format.  Not the most efficient way to do it, but simple enough.  1KHz is pretty much the max rate for all of this data, but Arduino Plotter seems able to handle it.