Hobbyist Toolkit
Digital Input on Raspberry Pi
Solved!
Shell command now works OK natively on the RPi terminal but I might not try SSH trick and system exec command for LabVIEW (yet) as I no longer have a need for this given I now rely on the default pullup/pulldown settings, BUT I do note that when using the raspi-gpio command and SETting up any GPIO pin as input and programming the pullup or pulldown resistor, I confirm level as expected with raspi-gpio, yet when I then try to read the same level back via LabVIEW , it does NOT read back the correct level. It is possibly because I am freshly opening a ref to the RPi, and LabVIEW resets the pin config back to default per the following snippet
Unfortunately there are several different ways to handle GPIO on Linux. The original way as was recommended/working around 2013 (when the Linx Toolkit was developed) was eventually depreciated by the Linux folks and replaced by a different one that provided more control over the various features such as open collector, pullup resistors and direction control of GPIO pins, including better support for frequency generation directly inside the kernel module, to achieve a better latency and accuracy.
The Linx Toolkit still uses the old variant that simply does not provide all the control that you would like to have. Additional complication here is that the Linx Toolkit environment to deploy VIs to Raspberry Pi and Beaglebone Black executes not directly inside the host OS but in a chroot jail with its own NI Linux RT based kernel (with RT capabilities disabled). That means that not everything a kernel driver tries to do can be really done inside this chroot environment. Every resource needs to be specifically enabled in a configuration file during initialization of the chroot, to be even visible to any software running in the chroot, and some things simply can't be enabled, as direct hardware access is pretty much impossible.
