Package: di2008
PurposeTo provide an easy-to-use, object-oriented instrument interface for theDATAQ DI-2008from within any
Python environment.The intent of this project is not to provide an API that will be useful in 100%
of use cases, but will target the 90%.  In my experience, most of us need pretty
basic functionality and have only modest timing requirements when working with
such instrumentation.  As a result of this, the API will attempt to abstract
away the lowest-level functionality which may result in a hiding or loss of
feature implementation available in the hardware.  If this happens to you, feel
free to use the nuts and bolts exposed herein to inform your own development or,
better yet, send us a pull request!Check out thedocumentation!InstallationThe hardware drivers must be installed before this package may be utilized.  Hardware
drivers may be downloaded from themanufacturer's product page.Once drivers are installed:$> pip install di2008Project Status and FutureThe objects provided are tested and demonstrated to function well, however, there are still some features that have not been implemented.Items marked out have already been completed.  The list is in approximate order of priority and marked out items have been completed.Implement Analog Scan ListcompleteRead ThermocouplescompleteRead Analog InputscompleteRead Rate InputcompleteRead Event InputRead Counter InputRead Digital Input(s)completeWrite to Digital OutputscompleteBetter sample hardware timing controlHardware SynchronizationUsageRegarding the specifics of usage, it may be very helpful for the user to read the device documentation so that some of the concepts enshrined herein are more precisely interpreted.  Specifically, the concept of a "scan list" is somewhat unique to the product and difficult to abstract.  As the project matures, more of the hardware idiosyncrasies are expected to be exposed to the user.DeploymentWhen deploying usingpyinstallerin a windows environment, thepyusblibrary doesn't
play well withlibusb-1.0.dll, so you will need to packagelibusb0.dllinto your
pyinsteller*.specfile using the following line:datas=[('C:\\Windows\\System32\\libusb0.dll', '.'),],Hardware SetupPlace device into 'USB' mode, not COM mode!!!Disconnect from USBWait 5 secondsConnect to USB and press button on side rapidly until LED changesThe device setting is persistent and will not need to be changed again.If you see a COM port in your device manager with the labelDATAQ DI-2008then the device is NOT in the correct mode!Software SetupTo read a few analog inputs, device setup is relatively simple.Define the portsCreate theDi2008instanceAdd the scan listStart the scanning processRead inputs at whatever timing is desired as the inputs will be updated "live"Some sample code might be more illuminating.  A simple script to set up the scan list and to print the values every second:from time import sleep
from di2008 import AnalogPort, RatePort, Di2008

# create each of the inputs that need to be sampled
an0 = AnalogPort(1, analog_range=10.0, filter='average')
an1 = AnalogPort(2, thermocouple_type='j')
an2 = AnalogPort(3, thermocouple_type='j')
rate = RatePort(5000)

daq = Di2008()
daq.create_scan_list(
    [an0, an1, an2, rate]
)
daq.start()

while True:
    print(f'{an0.value:.02f}')
    print(f'{an1.value:.02f}')
    print(f'{an2.value:.02f}')
    print(f'{rate.value:.02f}')
    print()
    
    sleep(1.0)