Asked — Edited

Press Of A Button.Led

I have an LED magician and I'd like to be able to control the routine and the speed using ezb. Doable? If so how do i set it up in EZ builder. How do i connect it to the EZB? The manual discusses using a micro controller at the bottom of the manual.


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Do you have any links to the manual?


<smart aleck comment> - "Is your magician named David Copperfield?"

This looks like the manual: Manual

"Installing external controls You can wire-out external controls by using the through-holes located at the top right corner of the circuit board. Using a micro-controller; A "push" of the control buttons are simulated via an "active low" TTL signal from your micro-controller. The connection should be kept "high" at 5v and a "low" level signal simulates a press of the switch. Have a question? Find your answers at our "Frequently Asked Questions" page"

This sounds like a digital on/off. Nothing fancy like a serial or i2c interface, just a digital port like you would connect a servo. I do forget what the a digital high outputs are now on the v4 (voltage wise), so check and double check voltages before you connect it up! And don't forget your common ground between your Magician and the v4.

And you would need a digital line for each button on the magician. The one I saw had 4 buttons, which means 4 digital lines.


Thanks Justin. I have 7.4 volts going to the ezb4 unregulated, I assume 7.4 volts going out. I'll have to get another step down regulator to 5v. ( or 4 if I want all 4 buttons active) . But with wiring am I connecting ground and signal or ground and +5v always get confused on when to use either.


Ground for sure.

Ok, signal vs +V are, very different things. (You may know this, but I'd like to explain it anyway) So on the digital ports you have 3 pins Signal, +V and ground. +V and ground are a straight power source, if you have 7.4 volts going into the v4 you'll get that voltage out of your +V - just like a voltage regular or straight from a battery.

The Signal wire is the special wire and important one. It can provide a digital on/off or high/low signal, PWM for servos, etc. It can also receive digital on/off or high/low signals. The signal wire (unlike the +V) should only output a signal voltage at TTL levels or either 5V or 3.3V for high or on. No voltage, means a low of off signal. The 5v vs. 3.3 is what I forgot on the v4 the DataSheet says this:

"Digital I/O TTL Voltage Level (input high) min 1.6 max 5 unit VDC Digital I/O TTL Voltage Level (input low) min 0 max 1 unit VDC Digital I/O TTL Voltage Level (output) min - max 3.3 unit VDC"

With that in mind, you can output a 3.3 signal to the LED Magician, just make sure please it is the signal wire!

You should be good to go but technically the LED Magician says it is looking for +5V for the signal high and the v4 will send an output of +3.3v. My guess is it would work fine, but if it does not work you might need a TTL booster to bring the signal from 3.3v to +5v. Does that make sense?

To power the LED Magician board itself the manual had this to say:

"Before you can start using the LED Magician, please select the correct input voltage by shorting the connections labelled "8-28V" or "4.5V".

If you are using an input voltage that is between 4.5Volts to 8Volts, solder the connection labelled "4.5V" (Fig. 1)

If you are using an input voltage that is 8Volts and above, solder the connection labelled "8-28V" (Fig. 2)"


Excellent information. Thanks very much !


...yeah the 3.3 v volts needs to be brought up to 5v, wont trigger. Should i step down the +v side to 5 volts and use that, or do i have to step up the 3.3v signal wire?


Remember the +V is like a battery or any other power source, so if you connect that to your trigger on the LED magician it is going to be like you are always pressing the button, you would have no control. No way to control on/off or high low signals unless you turned the ezb v4 on and off, which is not what you want.

The signal wire output is the only way to have on/off, high/low control that you need for the LED magician.

I would test the LED Magician with a different 5 volt signal (to replicate the TTL signal), just to make sure it is working correctly. By test, I mean you should be able to momentarily feed 5 volts to the TTL input on the magician and it should replicate a button being pressed manually on the magician.

If that works you can either use ttl converts to boost the signal voltage or you could opt to use a micro controller that natively outputs 5 volts for a digital high and connect that micro controller to the EZBv4 via a serial port.


Excellent find. I will give the +5 v a try with external power and see if it works. I also saw this from the manual:

The connection should be kept "high" at 5v and a "low" level signal simulates a press of the switch.


Yeah, I saw that when I copied it a few post back, I guess my brain blocked it out because in my mind that seems backwards, but who am I to argue with a magician. :)


Ha. seems that the pins are always active with 5v all the time. I took an alligator clip and put it to ground and it worked like a button push. I also found out the labeling is reversed on my PCB, the speed controls are the mode controls, only figured that out by tracing the circuit on the bottom. The digital control seems to work, but seems to have to push twice to get the mode to change. But happy its working to a degree.


Hummm, so that makes me think that the high value from the ezbV4 should not matter, because the magician is always in a high state, it's just the low state that produces the TTL switch signal....did you try setting the digital port to off or low on the magician?


Yes i did and it triggers the mode to change. but when i switch the digital port in ARC it to on, it seems to act as a power off for a second and starts the demo mode, so i have to quickly press again and it starts changing the mode again. So its like 3 quick presses of the digital button to change the modes...crazy, but it works..ish


Ehh, phooie on that. It must really need that 5 volts. It's good to know though, because it looks like an awesome LED controller. Thanks for sharing your experiences with it and experimenting. :)