I am trying to set up a system with a mega 2560 and a TFT LCD display. I have 12v white led strips that I want to be able to toggle on and off using a button on the touchscreen. My original plan was to wire power to the LEDs through the arduino, but it can only supply 5v from what I can tell. So I bought a 12v battery holder that takes AA batteries. I am stuck in wiring the system though. How do I pull power for the LEDs through the battery pack but also connect the LEDs to the arduino so I can control them?
A relay could do the trick. Try the words "arduino relay run 12v motor" in a internet search thingy.
A relay - which is to say a relay module would be a very crude approach.
If you care to play the game and cite - with a Web link - what the LED strips are and how many you wish to control in what groups, we may have something better to suggest. 
I am building a shelving unit with lights. As of right now, I’d like to have 2 lights on each shelf and have 4 shelf’s total so I’d have 8 lights in the system. If 8 lights complicates the system to much, I’ll just use 4 lights instead. Does the changing from 8 to 4 lights make it easier?
It remains that without knowing - a Web link - what these 8 "lights" actually are, we have nothing to say. 
You have reminded me that I bought from Aldi a battery operated PIR controlled cupboard light with a LED strip that I mean to install having cut the strip into two pieces for two shelves. Must get on to that. 
I apologize, I forgot to send the link for the lights in my previous post. Here it is: https://www.amazon.com/DD01WM-10pcs-Wired-Self-adhesive-Flexible/dp/B07CJ9KZ4T/ref=asc_df_B07CJ9KZ4T/?tag=hyprod-20&linkCode=df0&hvadid=416750690396&hvpos=&hvnetw=g&hvrand=17361594510660863900&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9030087&hvtargid=pla-882677528520&psc=1&tag=&ref=&adgrpid=92049667097&hvpone=&hvptwo=&hvadid=416750690396&hvpos=&hvnetw=g&hvrand=17361594510660863900&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9030087&hvtargid=pla-882677528520
Actually the link is just: https://www.amazon.com/DD01WM-10pcs-Wired-Self-adhesive-Flexible/dp/B07CJ9KZ4T
So, you need to switch 12 V, and 30 mA per LED strip (of three), eight of those switched together would be 240 mA and a transistor to switch them such as the popular 2N2222 with a 180 Ohm base resistor.
Just to turn a light on, I am now wondering why you would want a Mega 2560 and a TFT display however. 
I got the mega 2560 and tft display because I eventually want to add more functionality to the system down the line and use the touchscreen to control it all. Are you possibly able to draw up a simple wiring diagram for what I would generally need to do for 2 light/ or something? I can just copy that for the rest because I’m wiring each set of 2 in series so the sets can be turned on individually. I have a much easier time understanding what to do based off pictures, I’m more of a visual learner and have a hard time putting it together when it’s just in words.
I am trying to use a mega 2560 board and LCD shield to control LEDs with a touchscreen. I am working on the wiring right now and need a bit of guidance. I know I need to use transistors because the lights are 12v and the board can only provide 5v so I got an external power source to power the LEDs. Do I need a transistor for each LED that I want to wire in? If not, how would y'all recommend I wire this safely?
Yes for every 12V LED module. A current limiting resistor may be required as well.
The title of your topic is confusing. You never wire LEDs or transistors in parallel. If you mean "in series" then please update the title accordingly.
The best approach is to:
wire a resistor in series with each LED (5 LED's 5 Resistors)
You can wire these series connect LED and resistor in parallel.
Connect one end to +12.
Connect the other end to a "transistor" that when ON will essentially ground the other end of the resistor + LED.
I would not use a transistor but you should use a Mosfet. Usually dissipates less power and can very easily be controlled from your mega.
Hi,
How many LEDs do you have and do you want to control each one individually or in fixed groups.
With your 12V LEDs you can put them in parallel and use a single BJT or MOSFET to control them as a group.
What 12V LEDs do you have, a link to specs/data and/or a picture of them would help.
You didn't say if your 12v LEDs are individual or in strips?
Thanks.. Tom.. 
How does this topic differ from Wiring white led strip into touchscreen arduino system - #8 by Paul_B
Clearly it does not. A merge would seem to be in order!
TOPIC MERGED.
Could you take a few moments to Learn How To Use The Forum.
Other general help and troubleshooting advice can be found here.
It will help you get the best out of the forum.
This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.