Hi, i am looking to run at least 3 or more RGB LED strips and am unclear on what is required. I am looking to run them at say 1Mtr lengths. Unsure what/if i need to use Mosfets, TPIC6B595, ULN2803APG or something completely different. I also want to keep the pin usage to a minimum where possible as will be adding more modules to the Arduino.
Lastly i also need to understand how to code them. IE, some examples of code.
30 Led's per Mtr
Working input Voltage: 12V DC
Working power: 4.8W/Mtr (0.16mA per LED)
Working Current/Mtr: 0.35-1.2A
I would appreciate any advise as where to start. New to electronics (but can program ,been quite some time in c thou) so be easy. Thanks.
For starters, Arduino provides 5v and your LED strip requires 12v. You either need to power the strip with a seperate 12v battery and then control it with a relay, or use a DC-DC boost module so the Arduino can control 12v like this one. For the current requirements, it is probably a better idea to use a 12v battery with an Arduino relay module, like this. You just wire the cable into the screw terminals. This would mean that you need 1 digital Arduino pin to switch on/off the device.
For controlling the colour of the strip with RGB, what is the pinout of the strip? Does it have 3 analog pins, one red, one green and one blue? Please post an image of your strip or of the pinout, or a link to the website where you bought it.
The cheap strips are not addressable, all the LEDs in the strip are the same colour. Using a relay is only any good for showing seven basic colours at full brightness. For other colours you have to provide the LEDs with a PWM signal on each of the three colour signals. As there are only 6 outputs capable of a PWM output on the Uno that is just three strips.
This shows you what to do.
You would be better off using a Neopixels strip or sometimes called a WS2812 strip, as that is 5V only and each led can be set to a separate or the same colour. Adafruit also have a tutorial on using that one as well, search for it.
The module has a control box as shown in the instructions lower on the page, which plugs into the module using a plug, you will probably need to work out what each of the wires do by checking what each wire is connected to in the control box
LEDs received...none the wiser as there just as I expected LEDs.
No they are not. The picture is not very good at showing what you have but it looks to me like you have a non addressable strip with built in resistors the type that has 3 LEDs in series.
To drive those you need a FET for each colour pulling down to ground and your common anode connected to your 12V supply. You also need the negative of that supply to be connected to the ground of the Arduino.
The link in reply #3 will show you what to do in detail.
If you want all the strips to show the same colour simply connect all the anode connections to 12V and all the cathodes of each colour to the same FET. If you want the strips to show different colours then you need three FETs and so three PWM outputs for each strip.
Lastly i also need to understand how to code them.
Simple just set the PWM duty cycle to each FET driver using the misleadingly named analogWrite command. Nothing special.
