[Question about phase between digital output and analog waveform]

Hi Attila,

Thanks. We still need the arm version of 3.22.14 (2024-03-25) for the correct phase adjustment. 

Yisi

[Question about phase between digital output and analog waveform]

Hi Attila,

The 3.22.14 (2024-03-25) solves the problem. Can also upload an arm64.deb version for working on Jetson? Thanks. 

Yisi

[Question about phase between digital output and analog waveform]

Hi Attilia,

I am trying to synchronize an 80Hz clock (from Digital output) and an 80 Hz customized analog waveform (see below). However, I am having an issue introducing a phase between them. While I can shift the phase of the analog signal, its range is much smaller than I expected. Below is the clock signal (yellow) and the analog waveform with different phases (0, 90, 180, 270 degrees), where I was expecting them to spread over one period instead of just ~1/4 period.   

My code for setting the analog waveform is as below. I tried to introduce the phase difference with FDwfAnalogOutPhaseSet & FDwfAnalogOutNodePhaseSet and had similar results, where "triggerPhase" was set to 0, 90, 180, 270. I wonder if I used the wrong function or if anything wrong with my setting?

        nRet = dwf.FDwfAnalogOutMasterSet(hdwf, c_int(LG_Chan), c_int(1));
        nRet = dwf.FDwfAnalogOutNodeFunctionSet(hdwf, c_int(LG_Chan), c_int(0), funcCustom);
        nRet = dwf.FDwfAnalogOutNodeFrequencySet(hdwf, c_int(LG_Chan), AnalogOutNodeCarrier, c_double(DACFreq));
        # dwf. FDwfAnalogOutTriggerSourceSet(hdwf, c_int(LG_Chan), trigsrcNone)
        dwf. FDwfAnalogOutTriggerSourceSet(hdwf, c_int(LG_Chan), trigsrcDigitalOut)
        dwf.FDwfAnalogOutTriggerSlopeSet(hdwf, c_int(LG_Chan), DwfTriggerSlopeRise)
        
        nRet = dwf.FDwfAnalogOutNodeDataSet(hdwf, -1, AnalogOutNodeCarrier, DAC, c_int(len(DAC)));
        nRet = dwf.FDwfAnalogOutNodeAmplitudeSet(hdwf, c_int(LG_Chan), c_int(0), c_double(absmax));
        nRet = dwf.FDwfAnalogOutNodeOffsetSet(hdwf, c_int(LG_Chan), c_int(0), c_int(0));
        # nRet = dwf.FDwfAnalogOutNodePhaseSet(hdwf, c_int(LG_Chan), c_int(0), c_double(triggerPhase));
        nRet = dwf.FDwfAnalogOutPhaseSet(hdwf, c_int(LG_Chan), c_double(triggerPhase));
        
        dwf.FDwfAnalogOutConfigure(hdwf, c_int(LG_Chan), c_int(1))
        time.sleep(0.1)
        dwf.FDwfDigitalOutConfigure(hdwf, c_int(1))

Thanks again for the help.

Yisi

[issue running I2C & digital IO output on Discovery 3]

Thanks for the response.

So you mean I cannot have I2C and Digital Output at the same time. Is there a way to disable I2C after I setup my board so I can turn on Digital output? Which command should I use?

The frequency I am trying to generate is 100Hz so the trigger IO is way too fast for me. And I am already using the two analog-out channels for other functions. 

Best,

Yisi

[issue running I2C & digital IO output on Discovery 3]

Hi Attilia,

I am trying to run I2C (IO 3&4) and have digital output (IO 5&6) as clock together. I tested each function separately and run well (except  FDwfDigitalIOOutputEnableSet bahaves oppositely to the reference as in my previous question). Yet, when I put them together, I2C always works but the digital output will stop once there is a I2C write. Below is my code (in python). 

Also, I want to set IO 6 as low (or high)  and wonder if there is simpler way than using pulse as in the code?

And I want to set FDwfDigitalOutModeSet to PP but cannot find any reference or sample code on how to do that.

Thanks. 

Yisi

# setup digital IO for trigger pattern 
print("configuring trigger")
# enable output for DIO 5, disable 6 so it is low 
dwf.FDwfDigitalIOOutputEnableSet(hdwf, c_int(0x0000)) # 1<<1
pfsOutputEnable = (c_uint*16)()
dwf.FDwfDigitalIOOutputEnableGet(hdwf, byref(pfsOutputEnable))
print("FDwfDigitalIOOutputEnableGet", pfsOutputEnable)
# set value on enabled IO pins
dwf.FDwfDigitalIOOutputSet(hdwf, c_int(0x0000)) # DIO-5&6 low
dwf.FDwfDigitalIOConfigure(hdwf)
# dwf.FDwfDigitalOutTriggerSlopeSet(hdwf, c_int(0)) # 0: rise, 1: fall, 2: either

# configure and start clock
hzSys = c_double()
dwf.FDwfDigitalOutInternalClockInfo(hdwf, byref(hzSys))
print("internal frequency: ", hzSys)
# 80 Hz pulse on DIO-5
dwf.FDwfDigitalOutEnableSet(hdwf, c_int(5), c_int(1))
# prescaler to double, SystemFrequency/xHz/2
dwf.FDwfDigitalOutDividerSet(hdwf, c_int(5), c_int(int(hzSys.value/80/2)))
# 50% duty cycle, 1 tick low, 1 tick high
dwf.FDwfDigitalOutCounterSet(hdwf, c_int(5), c_int(1), c_int(1))
dwf.FDwfDigitalOutConfigure(hdwf, c_int(1))

# low Hz pulse on DIO-6
dwf.FDwfDigitalOutEnableSet(hdwf, c_int(6), c_int(1))
# prescaler to double, SystemFrequency/xHz/2
dwf.FDwfDigitalOutDividerSet(hdwf, c_int(6), c_int(int(hzSys.value/80/2)))
# 50% duty cycle, 1 tick low, 1 tick high
dwf.FDwfDigitalOutCounterSet(hdwf, c_int(6), c_int(1), c_int(0))
dwf.FDwfDigitalOutConfigure(hdwf, c_int(1))

print("IO configured")
time.sleep(3)

# setup I2C
print("Configuring I2C...")
iNak = c_int()
dwf.FDwfDigitalI2cRateSet(hdwf, c_double(1e5)) # 100kHz
dwf.FDwfDigitalI2cSclSet(hdwf, c_int(3)) # SCL = DIO-0
dwf.FDwfDigitalI2cSdaSet(hdwf, c_int(4)) # SDA = DIO-1
dwf.FDwfDigitalI2cClear(hdwf, byref(iNak))
if iNak.value == 0:
    print("I2C bus error. Check the pull-ups.")
    # quit()
time.sleep(1)

rgTX = (c_ubyte*16)(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15)
rgRX = (c_ubyte*16)()

I2C_Addresses = ""
I2Cadd = [0xa,0xd,0x44,0x49,0x4a,0x4b]
# for i in range(8,119):
for i in I2Cadd:
    # print(c_int(i<<1))
    blnCheck = dwf.FDwfDigitalI2cWriteOne(hdwf, c_int(i<<1),None, byref(iNak))
    # blnCheck = dwf.FDwfDigitalI2cRead(hdwf, c_int(i<<1), rgRX, c_int(1), byref(iNak))
    print(i, blnCheck, iNak)
    if iNak.value == 0:
        I2C_Addresses = I2C_Addresses + str(i)+" "

print("I2C addresses: ", I2C_Addresses)

print("values of output pins: ", dwf.FDwfDigitalIOOutputGet(hdwf, 0x00))
time.sleep(0.1)

 

[question about FDwfDigitalIOOutputEnableSet]

Hi Attila,

I am using discovery 3 and downloaded the latest version of waveform. I just notice that the python code 

dwf.FDwfDigitalIOOutputEnableSet(hdwf, c_int(0x00ff))

actually disables pins as output, while c_int(0x00) enables them, which is opposite to what says in the reference.

I wonder if I misunderstood anything here?

Thanks.

Best,

Yisi