# Use IRF540 MOSFET to control LED strip

I was hoping to use this mosfet shield to control a "Standard 3528 12V LED strip". The shield looks like this:

However, it doesn't come with a datasheet (I guess that's my fault for being cheap) and now I'm confused about how to connect this to my Arduino Nano / Wemos D1. The black connector has +, - and s on the bottom but both blue connectors have no labeling whatsoever. So I'm not sure how to connect it to the 12V and Arduino. I've googled but haven't been able to find any documentation on this shield other than lots of sites offering it and with the same (or similar) pictures but never with any labeling. Maybe these things are so common that 'everybody knows' how to connect them?

The MOSFET is an IRF540. Also; I've read somewhere that I may need a transistor or "driver" to get the MOSFET to switch?

I have relays lying around and they work fine for my purposes but I was hoping to switch the LED strip without the noticeable click of a relay, so that's why I was looking into this MOSFET. (I also have some solid state relays laying around, but they're for AC).

• Buying EE stuff that doesn't have a data sheet isn't being cheap because it's likely you won't get the best performance without reverse engineering it to understand it and this costs more (time is money etc.) than buying the right goods in the first place and saving everyone's time who reads this post. – Andy aka Nov 6 '18 at 16:15
• The sloppy placement of the components is not making me optimistic about this board. – Elliot Alderson Nov 6 '18 at 16:24
• That power mosfet is literally touching the connector to the microcontroller and defeating the protection of the optocoupler... I would advise not using this board, it looks like something designed by a beginner who didn't know what they were doing. – Hearth Nov 6 '18 at 17:17
• Get in touch with the supplier and ask for documentation rather than just complain about the lack. I'm sure the supplier has had to deal with question on the connections if they are not marked. The board is however simple enough you could trace the circuit easily. – Jack Creasey Nov 6 '18 at 17:19
• I pointed out myself I probably shouldn't have so cheap; no need to point it out again and it's not helpful in any way. I know the board doesn't look great in the photo; my actual board(s, I got 4...) look much better. I can try to contact the seller but I have a feeling that's not going to get me far (again: shouldn't have been so cheap). HOWEVER; this is all I currently got lying around. I don't have drawers and drawers full of this stuff. Is there anyone that can help me figure this thing out (bootleg or not), even if it's only to see if I can get it to work? @Felthry: I got 2 of those too… – RobIII Nov 6 '18 at 17:25