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Getting error when running with custom firmware on pico with labview

cbohra00627

I am trying to create a labview driver for controlling the pi pico led. I went through the Digital Out Control.vi VI in pico_scpi_usbtmc_labtool and tried to replicate it for the led control. I took the blink example from pico-sdk examples directory and added the function to control led (i.e. gpio_put(LED_PIN, 1)) to the SCPI_DigitalOutput() function of gpio_utils.c file in pico_scpi_usbtmc_labtool. I created a new firmware with this change and loaded on pi pico. Now, whenever I do digital write HIGH, the led is turning on.

But when I tried to create a separate driver for led control with a separate SCPI command, I am getting some error while running the VI. The build was successful with my change and I loaded the firmware on the pico, but when I am trying to run my VI (snip attached below), I am getting the below error.

image

Code for led control:

led_utils.c:

image

led_utils.h

image

I have added the led executable and dir path to Cmakelists.txt and also added the INSTRUMENT_LED_OUTP_COMMANDS macro to scpi commands list in scpi-def.c

Am I missing something? Has anyone seen this error before?

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    This is failing in the init code, so it’s not even reaching your code.  One of the installed tools with LabVIEW is NI I/O Trace.  Run that, turn on tracing, then run the VI again and see if that gives you a clue to what is happening.  Also, don’t be afraid of putting a breakpoint on a wire and turning on the lightbulb, then single stepping though the code, probing wires to see values.  Sorry, I’m not at home right now so I’m talking from memory rather than with LabVIEW in front of me.

    I have seen his problem myself: the SCPI ID command would work with NI Visa Interactive Panel but not with my own Visa write.  Turned out that the string command I was sending, “*IDN?\n” was treating the “\n” as two characters and not a control character (new line).  The fix was to right click the string constant and make sure the “display \ codes” option was selected.

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  • 0

    This is failing in the init code, so it’s not even reaching your code.  One of the installed tools with LabVIEW is NI I/O Trace.  Run that, turn on tracing, then run the VI again and see if that gives you a clue to what is happening.  Also, don’t be afraid of putting a breakpoint on a wire and turning on the lightbulb, then single stepping though the code, probing wires to see values.  Sorry, I’m not at home right now so I’m talking from memory rather than with LabVIEW in front of me.

    I have seen his problem myself: the SCPI ID command would work with NI Visa Interactive Panel but not with my own Visa write.  Turned out that the string command I was sending, “*IDN?\n” was treating the “\n” as two characters and not a control character (new line).  The fix was to right click the string constant and make sure the “display \ codes” option was selected.

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