i have a bench PSU supplying 12v to a breadboard rail, from which i step down to 5.5v in order to run a capacitive moisture sensor and pump (via a relay). I plan to use the 12V rail to power the Uno eventualy.
The symptom of the problem is that there's no voltage at the relay output when the switch is closed, i've quadruple-checked wires and connections, swapped out both relay and pump but no joy.
Everything has a common ground, picture attached.
Component list :
LCD 1602 Keypad shield.
LM2596 to step down from 12V to 5V.
5V 10A/250VAC Relay.
Please excuse my bad paint skillz and thanks for any help