Relay turns ON only with signal -> GND

[hjelmar]

I have a relay module with external power pins (Vin, Gnd).
I use breadboard powersupply module for relay and Arduino Nano (so same Vin and Gnd).

Relay module is switched ON, if the Input pin (In1 or In2) is connected to ground.

If i use the blink sketch with correct PIN number to control relay, it won't turn ON, if the PIN state is LOW.
If i connect input to GND with wire, then relay switches ON.

Relay In1 input current is 4 mA.

Is there any possibility to drive this relay module directly with Arduino?
Or should i use transistor do drain In1 to GND?

[anon57585045]

You can easily drive it with an Arduino output, but you usually shouldn't power the relay coil from the Arduino.

Your module already has a drive transistor on board.

Please post a complete wiring diagram.

[hjelmar]

What then can be the "thing", that if i set pin to low, it does not turn the relay on?

[anon57585045]

It may use "negative logic" which turns the relay on when the input is LOW, or opposite logic. Please post a complete wiring diagram.

There is no "Vin" on your module, if it is the one shown in the image you posted.

[LarryD]

Always show us a good schematic of your proposed circuit.

Show us a good image of your ‘actual’ wiring.

Give links to components.

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In the Arduino IDE, use Ctrl T or CMD T to format your code then copy the complete sketch.

Use the < CODE / > icon from the ‘posting menu’ to attach the copied sketch.

[hjelmar]

Figured it out:
TL;DR: breadboard output voltage was to low (4.12V) for Arduino.

For uploading new code i disconnected breadboard power-supply module.
Uploaded new code and and powered circuit over usb and everything started to work.

If i disconnected USB cable and powered circuit again with this breadboard power-supply, then relays turn on but never switch off.

So i powered Arduino directly from bread-board power module USB and everything started to work.

Thanks for the feedback!

[LarryD]

@hjelmar

Figured it out: