Hardware Hacks

To this day, I have my first FPGA development kit with a Spartan-3 chip on board. I purchased it somewhere around 2004. Those were the days when Xilinx (today an AMD brand) provided the ISE development environment based on TCL scripts. My first Spartan S3 kit from Digilent Fast forward to 2026. The Spartan-3 chip has passed into history along with the ISE environment, which was replaced by the Vivado/Vitis combo. Through these nearly three decades, lithography technology has changed, enabling the creation of more efficient (in terms of speed and energy) chips. The functionality of the chips has also significantly expanded - it is no longer just FPGA structures with a synthesized MicroBlaze processor - but ready-made System on Chip systems that contain a combination of an ARM processor (PS block) with an FPGA structure (PL block). ...

I came up with the idea of expanding the “PID vs ML” article series to seriously investigate what are the real-world possibilities of augmenting classical PID controllers with self-diagnostics capabilities using FFT (unbalanced motor torque, gearbox damage, bearing faults, etc.). Of course my nature immediately kicked in. Instead of just slapping FFT onto the PID routines, calling it a day and ticking the ‘done’ box like a normal person, I did what I always do - tore the whole thing apart into pieces and started cursing stupid imperfection of the real computer world (as opposed to that beautiful, clean mathematical fantasy we all pretend exists). We’re talking about a finite number of samples, precision butchered by IEEE 754 float/double quirks, rounding errors that sneak in like uninvited guests, and … You think I’m nitpicking again…? Yeah, probably. My nature. But hold my coffee - I’ve got a perfect real-world example coming right up that shows why sometimes being this pedantic actually saves your ass. ...