Digital Discovery High-Speed Inputs (DINs) using Waveforms SDK issues.

[AstroKevin]

Hey, I seem to be having a very difficult time with the documentation on the WaveForms SDK using python. I can read/write all DIOs and do everything else using the GUI waveforms, but I cannot read DIN pin 8-23. I have been able to read DINs 0-7. 

I made a function to read a certain DIN, but then overwrote a few things because of troubleshooting, so the "pin_index" is really not used here as it prints all the pins out. 

 

Can you please help me figure out why I cannot see DIN pins 8-23? I should add that I have another Digital Discovery outputting simple high signals to pins 0, 3, 7, 8, and 20, but I only get 0,3, and 7 to show up.  

from ctypes import *
import configparser
import sys

# Load the dwf library
if sys.platform.startswith("win"):
    dwf = cdll.dwf
elif sys.platform.startswith("darwin"):
    dwf = cdll.LoadLibrary("/Library/Frameworks/dwf.framework/dwf")
else:
    dwf = cdll.LoadLibrary("libdwf.so")

def initialize_devices():
    """
    Initialize the Digilent Digital Discoveries
    """
    cDevice = c_int()
    devicename = create_string_buffer(64)
    serialnum = create_string_buffer(16)

    # Enumerate devices
    dwf.FDwfEnum(c_int(0), byref(cDevice))

    devices = []
    for iDevice in range(cDevice.value):
        dwf.FDwfEnumDeviceName(c_int(iDevice), devicename)
        dwf.FDwfEnumSN(c_int(iDevice), serialnum)
        devices.append((devicename.value.decode('utf-8'), serialnum.value.decode('utf-8')))

    return devices

devices = initialize_devices()

print(devices)

def open_device_by_serial(target_serial_number):
    """
    Open a device by its serial number
    """
    cDevice = c_int()
    serialnum = create_string_buffer(16)

    # Enumerate devices
    dwf.FDwfEnum(c_int(0), byref(cDevice))

    # Find the device with the target serial number
    for iDevice in range(cDevice.value):
        dwf.FDwfEnumSN(c_int(iDevice), serialnum)
        if serialnum.value.decode('utf-8') == target_serial_number:
            hdwf = c_int()
            dwf.FDwfDeviceOpen(c_int(iDevice), byref(hdwf))
            if hdwf.value == 0:
                raise RuntimeError("Failed to open device.")
            return hdwf

    raise ValueError(f"No device with serial number {target_serial_number} was found.")

def read_din_pin(pin_index):
    hdwf = open_device_by_serial(My_Serial)

    # Declare ctype variables
    sts = c_byte()
    cSamples = 8192
    rgwSamples = (c_uint32*cSamples)() # Adjusted for 32 bits
    cAvailable = c_int()
    cLost = c_int()
    cCorrupted = c_int()
    fLost = 0
    fCorrupted = 0

    # Set up acquisition
    dwf.FDwfDigitalInInternalClockInfo(hdwf, byref(c_double()))
    dwf.FDwfDigitalInDividerSet(hdwf, c_double(10))
    dwf.FDwfDigitalInSampleFormatSet(hdwf, c_int(32))  # Adjusted for 32 bits
    dwf.FDwfDigitalInBufferSizeSet(hdwf, c_int(cSamples))
    dwf.FDwfDigitalInTriggerAutoTimeoutSet(hdwf, c_double(10))
    dwf.FDwfDigitalInTriggerSourceSet(hdwf, c_ubyte(0))
    dwf.FDwfDigitalInTriggerSet(hdwf, c_int(0), c_int(0), c_int(0), c_int(0))

    # Set sensible mask for specific pin
    mask = 1 << pin_index  # This will create a mask that enables only the specified pin
    dwf.FDwfDigitalInSampleSensibleSet(hdwf, c_int(mask))
    # Set trigger position
    dwf.FDwfDigitalInTriggerPositionSet(hdwf, c_int(8191)) # 8191 is one less than cSamples

    # Start signal generation
    dwf.FDwfDigitalInConfigure(hdwf, c_bool(False), c_bool(True))

    # Wait until done
    while True:
        dwf.FDwfDigitalInStatus(hdwf, c_int(1), byref(sts))
        if sts.value == 2: # DONE
            break
        time.sleep(0.1)

    # Get sample
    dwf.FDwfDigitalInStatusData(hdwf, rgwSamples, 4*cSamples)  # Adjusted for 32 bits
    print(rgwSamples[:10])
    # Close device
    dwf.FDwfDeviceCloseAll()

    # Extract pin state from sample (for easier reading)
    for pin_index in range(24):
        pin_state = (rgwSamples[0] >> pin_index) & 1
        print(f"Pin {pin_index}: {pin_state}")

    return pin_state

read_din_pin(0)

 

Edited July 18, 2023 by AstroKevin

[attila]

Hi @AstroKevin

The FDwfDigitalInDividerSet expects integer number, like:
dwf.FDwfDigitalInDividerSet(hdwf, c_uint(8))

Casting double probably it received 0 and actually captured 8bit samples.
At 800MHz (div 1) it will only capture 8bit samples, at 400MHz (div 2) up to 16bits, at 200MHz (div 4) up to 32bits.

The latest software version adds 64bit sampling mode (40bit useful inputs with Digital Discovery), for 100MHz or lower (div 8)

 

[AstroKevin]

Ooof, I don't know how I missed that, but it works perfectly now! Thank you.