I looked at the Intel Cyclone 10 GX FPGA Development Kit User Guide 4.5.3. LEDs Table 13 to see which Pins I have have to choose in the Pin Planner/Assignment Editor to use for my Blinky Test Application.
Problem is D21 and Pushbuttons are not assignable at all (D21 is GND see picture) and the other LEDs wont turn on. Am I reading this wrong?
Welcome to INTEL forum. In C10 GX dev kit user manual table 13 (board reference of D21 is referring to actual LED on board that’s called D21 as shown in schematic page 33, this is not referring to FPGA pin location)
For Quartus design pin assignment – by tracing the LED D21 is connected to which FPGA pin location based on the connection signal name “USER_LED2”. This lead to FPGA pin AC6. In your case, you needs to assign FPGA pin location = AC6 in his Quartus design, not D21.