I have ordered two Drok voltage regulators from Amazon (DROK LM2596 DC Buck Voltage Regulator 36V to 24V 12V 5V 3.3V 3V Converters Constant Volt and Amp 5-36V to 1.25-32V 5A 75W), one is order number 002-1346411-2347411. No matter what I do, my input voltage equals my output voltage. I need 9volts in, and 5 volts out for my Arduino boards. The pots on the board are not identified, and no matter how far I turn either one, the output voltage does not vary. My input source is a BK Precision DC power supply, and I am checking the output with both your LED display and my Fluke DVM. There was no documentation provided, and I am stuck. Can you please provide some direction? Also… Which pot is voltage? Which direction decreases output voltage? How many turns is this pot from minimum to maximum. I’d like to order more of these, but I’d better understand them first.

Lastly, is this the best board for my purpose?

I hope I have been clear. Please help!