Here are a few things to try. 1: if you connect the output of the 12V inverter directly to your tape, is it brighter or still dim? (This will tell us if the board or the inverter is at fault). 2: If it's dim and you have a better inverter, you can always connect the better inverter to the board. 3: the Dos is great at running long lengths of EL but doesn't always do well with short lengths (it needs a minimum load to turn on and off efficiently). You can try shorting a 100k resistor across the output (the pairs of holes marked "~ ~" on the bottom of the board are perfect for this) and see if that helps. 4: Our tech support department is great at solving problems like this; give them a try.

There are links the schematic and triac datasheet in the product description above, those documents should answer your questions.

Hi, I have the same problem. Since the board is used in a costume, sometimes an EL wire causes a short circuit because of moving with the suit. So if one of the 8 channels has a short, the whole costume doesn't work anymore. The boards worked the last 6 months in this configuration. Now to solve this I separated the HV and HVGND of each pair of channels by cutting the traces, and connected 4 inverters. So when one pair of channels has a short, the other 3 pairs remain working. I would think this should work, because there are now 4 separate isolated circuits. But somehow after this modification now some of the triacs are blown after a few seconds/minutes of use! Some are 'always on', some light up erratically. I don't have a clue what could cause this, I have 6 boards and 3 of them have this fenomena. (I'm afraid of further frying the other 3). Now I'm thinking of reconnecting all the HVGND connections, so all the inverters share the same HVGND, maybe this will solve the issue? I'll try this weekend... Or does someone have a clue?

There isn't a provided fade command or library, but you can use PWM (analogWrite) on channels B,D,E and H, or write your own fast-blink code for any channel.

Note that fading burned out the triacs on the old EL Escudo, so the newer Dos version has zero-crossing triacs that are bulletproof, but don't fade as smoothly as the old one. If you use analogWrite, you'll notice that some dimming levels flicker. You should still be able to find PWM values that give you broad but stable dimming steps.

As long as you change the NeoPixel data pin to something unused by this shield (the shield uses pins D2 through D10), you shouldn't have any problems.

The AC switches on this shield should be able to handle that load, provided you have a strong enough inverter. This shield only uses D2 through D10, leaving the rest of the digital and all of the analog pins free.

D11, D12, and D13 are all digital pins available for a button connection, if you aren't stacking anything else on your Arduino requiring those pins.

Thank you for pointing out that new wire! It looks really neat and we're looking into what it would take to drive it. Our best guess at this point is that it combines several EL channels into one wire, so you'd need to allocate several (3?) channels of your EL Escudo / EL Sequencer for each strand of chasing wire. Software wise this would be easy enough to drive, you'd just repeatedly sequence through the channels. Hardware wise they say it uses a special connector, so you'd need to either find the matching connector (we're looking into it), or cut off their connector and splice on several JST pigtails to match our driver boards. If you do get some, let us know how it works and if we can help further.

We're very sorry to hear about your problems. The EL Escudo has two identical connectors for DC out and AC in; is it possible that your inverter output was plugged into the DC out connector? This would send 100VAC+ into the VIN line likely damaging any Arduino plugged into the board. Again, sorry for your problems, please contact our Tech Support department, who will be able to assist you further.

Can you tell if the Arduino itself is frozen, or just the shield? (For example, keep blinking the status LED; if the status LED stops you know the Arduino has frozen up).

My first guess is that your inverter + EL wire is drawing too much power from the Arduino, and that the Arduino is locking up. Ensure that you're powering the Arduino with a sufficient power supply for both the Arduino and your EL wire (9 or 12V wall wart recommended), or power the Inverter separately from the Arduino. If you continue to have problems, let our Technical Support department know and they'll be happy to help you out.

Yes you can, although it will run a bit dimmer than with an inverter. (The brightness is partially a function of the AC frequency; the higher the frequency, the brighter the output.)

You're right; anything with eight output pins (3.3V or 5V) can easily interface to this board.

We haven’t tested it all the way to these limits, but a rule of thumb I’ve seen is that each meter of EL wire uses 10mA or so of current. The triacs in the EL Escudo Dos are rated at 1A continuous and 8A peak. So in theory, each channel should be able to drive 100m (328') of wire without issues, and more if it’s not on continuously. Let us know how it works!

We've covered this in these comments before. The quick answer is you can get several broad steps from dim to bright, but not smooth dimming.

It's best to have a separate regulator for the inverter since it may need a specific voltage at more current than the Arduino can provide on its own.

We did the math and added them to make this board as robust as possible. Your mileage may vary with other designs.

We might have been able to get away with just the optotriacs, but they're traditionally not as beefy as discrete triacs, and we wanted to ensure that people with higher-current needs were accommodated.

Yes. We have seen some problems with the Uno not putting out a full 5V on the VIN pin when powered via USB, which causes the 3.3V regulator on the EL Escudo to malfunction. If you're not using USB for power (or you're bypassing the regulator), then it should work fine.

It is possible, with some hacking, to get two of these boards running on one Arduino. You'd need to cut the traces on one, and run those channels to open pins (16 will almost max it out).

You could also do this with two EL Sequencers, by connecting them together via serial and programming one to be the master controller and the second to be a slave.

USB is only 5V, which isn't enough to run the 12V inverters. If you're using 12V inverters, you will need 12V supplies for the Arduinos, and (as you already have,) you will need to close SJ1 to send 12V directly to the inverters. Then your systems should work fine.

See the tutorial at the top of this page, which walks you through all the power options.

We designed the board so that you could cut the traces between the Arduino and the various channels (e.g. A/D2 and B/D3) and patch those channels to unused I/O pins if you like. But (and I haven't tried this), I suspect that you can set up D2 and D3 to be inputs and use the interrupts without modification as long as you don't mind that a HIGH input (or pullup) would turn on that channel (you don't need to connect anything to it).

You probably don't want to do that; you'll lose all the outputs, which are the eight headers with the "~" symbols. The smaller row of 8 headers are the logic/LED inputs.

You might take a look at the EL Sequencer, which is about as narrow as what you want, but a bit longer in one dimension. You could also make your own PCB.

The back of the envelope says that the triacs should be able to handle up to 50kHz, so I'd guess such an inverter would work OK. If you try it, let us know how it goes!

Strange; we've successfully used it with a 3.3V Arduino Pro. Is that what you're using?

EDIT: Also ensure that the inverter regulator is correctly configured for your power supply; your inverter may not be getting the voltage it needs from the 3.3V Arduino.

See the tutorial linked in the documents at the top of the page. The one sentence version is: solder headers to the EL Escudo Dos, and plug it in.

We're not immediately planning on making a version for the Pi, but the requirements of this board are very simple, and it should be easy enough to wire eight digital outputs from the Pi into this board. I believe I've seen a Pi-to-Arduino-shield adapter board out there that may help as well (this board uses pins D2 through D9). Let us know how it goes!

That sounds like a great project! When you're designing something like this, you have to balance a lot of things, the number of output channels being a large one. More channels make a board larger and more expensive, with fewer people buying it because they don't need that capability. Eight channels seemed like a good balance between too few and too many, but thanks for the feedback; we're working on a stackable version for those of you who need to drive LOTS of channels. Also take a look at the EL Sequencer, which could be synchronized with other boards via software.

This was answered earlier in these comments (link), if that doesn't answer your question let us know.

The bottom line is that this shield needs eight digital outputs to control the eight EL channels. You can supply those lines from whatever you like (microcontroller, shift-register, etc.), but an FTDI cable doesn't have eight directly-controllable outputs, so that won't really help you here. If you want to control the eight channels from a computer via FTDI, you will need either an Arduino plus this shield, or an EL Sequencer (which has the Arduino built in to it).

Sorry for the late reply; for normal AC loads you'd need to be careful the combined current coming back on the common wire, but for EL this should work fine. Just ensure you're common-ing the correct side of the JST connectors, and try to keep the bundle tight to reduce possible radiated interference. Good luck!

No issues I can see, if your external circuit can light up an LED (5mA), you should be able to hack straight into the shield. Send us some video when you're done!

https://www.sparkfun.com/products/10878#comment-4fea44edce395f416a000000

It's a 2mm, 2-pin JST connector. We offer pigtails with this connector that you can easily splice onto your EL wire/tape/panels. You could also get the parts to build these connectors at Digi-Key, but you would have to crimp the pins yourself which is not easy.

Also, the tutorial linked at the top of this page has a good walk-through of all the steps necessary to get the EL Escudo working.

OK, let's check a few things.

Is the 3V inverter plugged into the EL Escudo with the red/black lead to the "DC TO INVERTER" connector, and the black/black lead to the "AC FROM INVERTER" connector?

Set your multimeter for AC Volts (and if it's not autorange, set the range to 200V or above). Now with everything powered on, carefully measure the voltage at the two holes just above the "AC FROM INVERTER" connector on the EL Escudo. (Run the red lead to one hole, and the black lead to the other hole. It doesn't matter which direction). You should see over 100V.

Let us know what you see, and we'll keep troubleshooting.

This shield certainly allows you to turn all 8 channels on at the same time. But it's the strength of your inverter which will determine how bright the EL wire glows. The inverter "sees" the sum total length of all the channels that are on, and if it can't handle that length, the wire will appear dim.

That's correct.

We haven't tested it all the way to these limits, but a rule of thumb I've seen is that each meter of EL wire uses 10mA or so of current. The triacs in the EL Escudo Dos are rated at 1A continuous and 8A peak. So in theory, each channel should be able to drive 100m (328') of wire without issues, and more if it's not on continuously. Let us know how it works!

Check out the tutorial above, it works with Sparkfun's 12V or 3V inverters, and with the correct connectors, should be adaptable to any other EL inverter out there.

This board only uses digital 2-9 (and 10 to a status LED you could disable), all the other pins including the analogs are free for your use. See the schematic for details.

I don't know what connectors Adafruit uses; all of our EL products come with a 2-pin, 2mm JST connector. If you do need to adapt something else, we do sell the correct pigtails.

i was missing the S1 jumper. works great now.

The quick answer is no, though it could be done with a substantial amount of rework. On this board, the eight EL channels are hardwired to Arduino digital pins 2 through 9. You could cut the traces from those pins to the drivers, and rewire the drivers to listen to another set of pins (there's a header on the board to make this somewhat easier), but it would be a bit of work and not allow more than two boards total.

If people would like this capability, let us know and we'll consider a variant that allows you to stack as many boards as you wish (more or less).

That's a really good question. Since we don't know the answer either, I ran one of our 12V inverters overnight without anything plugged into it, and when I just plugged it back into an EL shield, it appears to work just fine. I don't know about long-term effects, but running it "dry" doesn't appear to cause any immediate damage.

TL;DR: The new design solves the dying triac problem, at the expense of continuous dimming.

The old design couldn't enforce exactly when the AC could be switched on and off. This allowed continuous dimming, but because you could randomly switch in the middle of the AC waveform (where the voltages are largest), the parts could experience very large voltage transients. Not everyone had this issue, but a number of customers found that eventually these transients would kill the triacs.

The new design uses "zero-crossing" triacs, which means that if you turn them on or off, they will wait fractions of a millisecond until the AC waveform is at zero volts before switching. This makes everything electrically much quieter, and eliminates the possibility of damaging transients. We've found the board to be bulletproof in testing.

Unfortunately what you give up is continuous dimming - the triacs won't let you turn them on and off in fractional amounts, so you're limited to half-wave steps. We've found that you can still get several broad zones of stable dimming (say 6 or 8 steps from full-on to full-off), but intermediate PWM values will produce flickering (which is kind of cool too). The important thing is that you can't hurt the board by doing any of this, so feel free to experiment and let us know what you find.

Our distributors order from us on their own, so you should check with them directly to see when they'll have them in stock. Thanks and have fun!

Sure it would work, but that's a lot of surgery to perform on this board. It might be easier to find a more powerful inverter, or design your own board (you're welcome to use our schematic to do so). I'll mention that our 12V inverter is pretty beefy and can handle numerous simultaneous wires, as long as they're not hundreds of feet long.