How do I get rid of a cable? Pics of my WiShield/MAXM project included.

Hello Forum,

I followed and completed this guy's tutorial:

It combines an Uno, a WiFly Shield, and a MAXM combo (Blaster + Master). It changes RGB color according to what the weather is. Weather data is pulled in from the internet via WiFly Shield. The MAXM is powered by a 5v/1A DC adapter.

Here's my work:

Here's my QUESTION: [u]How do I power up the Arduino so that I can disconnect the USB cable?[/u]

I want to put this gadget in an enclosure and it would look better if I just had 1 wire (DC adapter) sticking out instead of 2 wires (DC + USB). Also, the USB cable is connected to my computer and I'd like to get free of it so I can place this gadget anywhere in my room.

More info: There's only 4 wires connecting Arduino to MAXM. Yellow & orange wires go to pins 4 & 5. The 2 red wires go to 5V and GND.

Any ideas? Is this even possible to have just 1 cable sticking out instead of 2?

Edit: Here's the datasheet for MAXM in case anyone is interested.


If its a nice regulated 5v you can put it right on the 5v bus of the arduino and have the grounds connected


I have and swapped in a 12V/1A DC adapter. But when I unplug the USB cable the green light on the Arduino turns off. Thus, I don't think the Arduino is powered and controlling the MAXM leds like it should. Thoughts?


The MAXM datasheet says that putting the MAXM right on the Arduino so that it is powered by Arduino pins 2,3,4,5 will not work. Is this what you mean?

If not, can you explain to me what you mean when you say I can put "it" on the 5v bus, and have the "grounds connected". Literally, I need a sense of how the wires are connecting, step-by-step.



Spycatcher and Winner,

The datasheet says it allows for input voltage 5V-12V (section 2.1.3).

Thus, I'm using 12V/1A DC adapter that plugs into MAXM.

Is that the info you are asking for?

Winner, I was wondering if you could answer my other reply to your post here at 9:38AM:,81834.msg616499.html#msg616499

I want to buy the parts you suggested but want to compose a parts list first.

Hi Spy,

I just plugged the 12V/1A Power supply into Arduino's power jack and disconnected the USB cable. The Arduino's green light is on, but MAXM does not power up.



Where is 5V on MAXM? On the breadboard there are 4 wires that run from Arduino to MAXM. See here:

This is my current setup in text. There are 4 thin wires, and 2 thicker cables.

4 wires (red, red, orange, yellow):

Arduino's 5V to red wire #1 to MAXM's plus terminal "+". Arduino's Ground to red wire #2 to MAXM's minus terminal "-". Arduino's pin #4 to orange wire to MAXM's "d" terminal. Arduino's pin #5 to yellow wire to MAXM's "c" terminal.

2 cables (DC adapter & USB):

12V DC adapter into MAXM's power jack. USB cable into Arduino's USB jack.

So, I'm not sure what you mean when you say connect a wire from 5V on Arduino to 5V on MAXM, and GND on Arduino to GND on MAXM....please elaborate? Sorry, but now you probably realize how noob I am to this stuff.


Hi Spy,

I'm looking and looking at page 7 of the Datasheet but still don't get it.

The Master is on the bottom, and the Blaster plugs into the top of the Master. So Blaster (top) and Master (bottom). Then, I plug the Master into the breadboard via the 4 pins at the bottom of the Master. They are labeled -, +, d, c. On the datasheet it is the "south" portion of the Master.

I think you're asking me to take the wire that goes from the Arduino's 5V pin, and connect to MAXM's 5v power out pin on the "east" side of the Master. Do I have that right? Because if you look at the Master it's connected to the Blaster and I don't know where to put the wire....



But, on a deeper level can you explain the "flow" of electricity. I clearly don't understand it well enough to understand why the change you made works.

In reality I only changed 2 things.

1) Switched the orange and yellow wires so that orange connects A4 to d instead of A4 to c. And yellow connects A5 to c instead of d. What did this accomplish?

2) Switched the jumper on Master to cover the bottom 2 pins instead of the top 2 pins. What did this accomplish?

Last, will this lower the amount of power that goes into making the RGB light BRIGHT?



Spy! Many many thanks for your helpful explanations. I've decided that I'm now officially hooked enough into this electronics/Arduino stuff to go buy some books on it. In front of me I already have Electronics For Dummies so I'm going to go through that first.

In the meantime, thanks for helping me get my gadget up and powered.

I'm thinking of taking your last comment and using it for my next project. I've never worked with a driver, controller, and super bright LEDs before so I'd like to learn. Can you help me compose a "parts list" of necessary component that I can buy from the internet.

I want to get a REALLY BRIGHT LED to light my room up with. Any suggestions? Once I choose a light I think buying the rest of the stuff falls into place (power supply, driver, PWM controller, heat sink, lense, etc).


Ok Spy, no worries as you've already helped me so much. Thanks for your help, I really appreciate it!

The only thing about the 10w led from sparkfun is that it is designed for 3 v which is a decent drop from 12, which means more wasted power in the current regulator and more heat, the ones you can find on ebay are usually around 9-12 volts which is better suited for your power supply voltage and the 5.99 price tag is nice