Ok, so I like electronic dance music, more specifically Trance. Unfortunately, the US, it's let's just say... a bit behind in that department. If you ever hear such music on the radio, or even in the street, let me know (for instance, in Australia, I heard great Trance in even a waterslide park of all places, and in Europe you can easily get EDM/Trance on broadcast radio).
Since 2004 (it's not 2016), the good news is that Trance has grown quite a following in the US, and places like the SF Bay Area, and while Trance has been declared dead a few times in the last 10 years, it's still going strong here, and we're lucky to have at least one or two big Trance parties per year, so yeah!
With San Francisco and San Jose nearby, I've had some opportunities to see some great EDM/Trance DJs. Back in the early 2000's, they sadly played club music in the US that was nowhere close to the hits they had composed and were known for, but over the years, as Trance started becoming more popular, those DJs finally started playing their good tunes in the US too, and maybe from 2004 on, it's only been getting better.
Over time, I've seen many of my favorite DJs across the world, whether it was locally, in New York City, Canada, Australia, and of course Ibiza, and at Halloween 2004, I finally attended some great local parties that proved that you could get the good stuff locally too (even if all the artists came from other countries .
Over the years, I also got the chance to meet a few of my favourite DJs, including Armin more than once:
It used a 12V controllable dimmer: https://www.amazon.com/gp/product/B00MHKCTLE which can simply change the brightness of the LEDs, which are of a set color. I bought the LED strip in Akihabara Japan, but I'm guessing something similar can be found elsewhere.
they are a flat trip that doesn't really like being bent
all the LEDs are in series, so if the chain fails somewhere, nothing lights up beyond the point of failure (which is why I have extra wires soldered on to make redundant paths and get around breakage
I have had some sections of 3 LEDs where one color died
All of the controllers I tried have a dimming function, but it fails to work when I use the fade dimming patterns, which means they are full bright, suck battery and blind others. I've therefore had to add a 2nd voltage regulator where I can just dim the voltage sufficiently so that the current is then also capped by each color string and therefore the brightness is controlled (you cannot limit the global current fed to the LED controller because you don't know whether it's all fed into a single color, or shared amongst 3).
Of course the last thing is that all the LEDs for a color are in series in a single circuit, so you light up all the reds, or all the blues or greens, or none. You can't turn on one LED individuallly. This is where the next solution comes in.
ESP8266/Arduino Controlled Neopixels
To fix the issue of not being able to have custom multi color LED patterns, where each LED/pixel can be controlled separately, the solution is neopixels (aka WS2811/WS2812/WS2812B). Each LED/pixel is controllable separately, which is done by a computer, in this case the ESP8266 can run my own programs to control all the LEDs.
The ESP8266 is a 3.3V based microcontroller for low power use (good when battery powered) while the neopixels are 5V powered, but thankfully the neopixels can use 3.3V signalling from the ESP8266 while being 5V powered to light up properly. The one thing to keep in mind is that neopixels use some power even if they are not lit. In my case 200 neopixels, take about 120mA when they are off, and 4.5A when they are all lit in white on full brightness.
Neopixels are almost infinitely versatile, instead of having them in single line strips like on my shirt and pants, you can also make display matrices out of them:
Last year, Dreamstate was in January, which was a bit cold and rainy when we got out. To be honest, it was much nicer in May, even if it was a bit close to EDC as a result. It was a great lineup, a nice 16 hours of trance with 16 DJs
This was the perfect excuse to go try my new shirt + pants with neopixels I had worked on (including new light effect code I wrote and battery saving patch to run up to 12H on a single battery). I found a few other people who were lit up, but compared to burning man where you'd get "oh, 200 neopixels, so cute, I have 1000 Watts' worth on my art car, they can be seen 2 miles away", there weren't too many people lit up. I found 5 or 6 of them though:
I've been a fan of Jean Michel Jarre since the 1980's when I was a teenager. Along with Vangelis, Jean Michel Jarre is one of the founders of Electronic Music. The two of them were popular before anyone else was even around doing any EDM.
Sadly, I never managed to go see him perform way back then, so it was super cool to see that he did a US tour and that I'd finally be able to see him. Better late than never...
Here's a video summary:
JMJ did a tune with Snowden
JMJ is most well known for his laser musical harp
Thanks to my friend Arnaud, we got invited to the after party for the crew:
The end goal was adding neopixel strips on my shirt sleeves and pant legs:
Here is a 6mn clip showing the shoes and shirt if you'd like the details:
The problem with my shirt, though, is that the colors you see on the picture are actually due to broken traces, causing the colors you see. It's better than nothing, but not what I was trying to do, and no way to create streaming effects. This is of course where neopixels come in.
I'm not going to repeat the excellent Adafruit Neopixel Uberguide here, but I have a 3mn video clip showing a standard IR RGB LED controller, compared to a neopixel strip. It also shows how I use standard remote control servo cables to wire neopixels, and how to watch out for:
signal wire being in the center, so you must not feed 5V on the middle wire like you would with RC and servos
how if you have a neopixel strip that doesn't work right, you can only connect to the first LED, and you have to start cutting off LEDs from the strip one by one until you get to the first one that works
before you start cutting, make very sure you aren't connecting to the last LED (DO vs DI)
Why IR and Neopixels at the same time, is hard
So, the main point of this page is however to look into the issues of controlling Neopixels and receiving IR signals at the same time.
It's easy to listen for IR, and then change neopixels, leave them alone, and listen for IR again. It's hard (or near impossible on some chips) to actively update neopixel strips for animations and listen for IR commands at the same time.
Why? This video explains the issue:
What's going on is on low end arduino chips (328p, leonardo, or even AT mega and all other 16 bit AVRs), neopixels are controlled by stopping chip interrupts and sending a very precisely timed signal to the neopixels. If the timing is off just a little bit, the wrong colors get sent, or nothing works at all. This is why interrupts must be disabled
Now, there are actually many other addressable multicolor LED types. The nice ones are 4 wire and work via SPI, which allows the CPU to control the timing and the clock, removing this exact bit banging timing issue. The cheaper 3 wire ones have a set clock and require that the CPU sends a very precisely timed signal, usually done while disabling interrupts. See https://github.com/FastLED/FastLED/wiki/Overview
But since neopixel strips (aka WS2811/WS2812/WS2812B) is what I already had, I now had to deal with this precise timing issue. As you can guess, disabling interrupts causes issues with the IRRemote library because it has its on interrupt handler timer that also requires being run at a special timing, or it doesn't capture proper IR signals.
The end result is that you cannot disable interrupts and receive IR signals, and if you don't disable interrupts, the neopixel signal is unstable and the colors flicker (demonstrated int the video above).
So, unless you use some special hardware to drive neopixels strips on an AVR chip, concurrent IR + neopixels is just not going to work.
an arduino nano v3 running neopixel strips
my 328p arduiny chip (equivalent to arduino nano) and anti plug backwards toothpicks :)
because my 328p chip was unprogrammed, I had to figure out direct ISP programming pinout for it and I flashed a bootloader on it
Concurrent IR + Neopixels solution #1: be fast (Teensy 3.1)
a few chips for comparison (uno, leostick, nano v3, arduiny, and Teensy 3.1 in green)
Thanks to better FastLED hardware support, when I moved my code to a Teensy 3.1 32 bit ARM CPU, the CPU was fast enough that it had time to re-enable interrupts in the middle of updating neopixels. This in turns allowed the IR Remote interrupt handler to just barely run in between pixel updates, and capture IR codes. Success!
See this video for details:
The magic code that makes this work, is here: https://github.com/FastLED/FastLED/blob/master/platforms/arm/k20/clockless_arm_k20.h#L34 sei(); delayMicroseconds(WAIT_TIME); cli();
Thanks to this re-enabling of interrupts, things work.
So at this point, someone sensible would have declared victory. However, I felt bad wasting a Teensy 3.1 on something as simple as driving a single neopixel strip (it can drive 8 in parallel) and reading from an IR receiver, when it has around 32 I/O ports. This is why I checked if I could get this to work on ESP8266 chips which are even cheaper and have much fewer I/O pins (but add Wifi)
Concurrent IR + Neopixels solution #2: don't use the CPU for neopixels (ESP8266 (I2S) and ESP32 (RMT))
I had more 32bit chips, so I thought I would give them a try. I tried the ESP8266 and ESP32:
However in my tests, the IRremoteESP8266 library was maybe a little bit too slow and caused occasional visible neopixel glitching. This is where I found this interesting library: https://github.com/JoDaNl/esp8266_ws2812_i2s/ which manages to drive the neopixels without doing bit banging with interrupts disabled ((ab)-using the I2S hardware support). It's not a very fancy library in what it offers, but it works perfectly with interrupts enabled.
Same thing for ESP32. Actually ESP32 is even more difficult to get a perfect timing out of using bit-banging given that it's a dual core CPU running on top of an RTOS, and no matter how precise your code is, you just cannot guarantee that it'll run perfectly at the timing you need all the time. I did add ESP32 support to the Adafruit Neopixel library, but it only works most of the time, which isn't really good enough.
This where its built in RMT support comes in. It can generate 8 precise signal waves, which are perfect for neopixels, so this is the way to go to animate neopixels without disabling interrupts (making IR receiving trivial). IRremote was missing ESP32 receive support, but I added it recently, so it's all working.
Here's a video summary of ESP8266 and ESP32:
Software and Libraries
So, here's a summary of all the libraries I went through, 2 for IR, and 4 for Neopixels:
FastLED is a more complete library with better hardware support (both in pixels and CPUs): https://github.com/FastLED/FastLED . The big plus of this lib is that it support re-enabling interrupts on 32bit chips, allowing the IRremote ISR to run.
Instead of FastLED (which does work), on ESP8266 you can use https://github.com/JoDaNl/esp8266_ws2812_i2s/ . The support is bare, but uses an inventive (ab)use of the I2S subsystem (I2C for audio) to generate neopixel signals using an onboard co-processor unit without tying up the main CPU or requiring the disabling of interrupts.
On ESP32, FastLED isn't supported yet (I added support in Adafruit-Neopixel) but both require disabling interrupts at least temporarily and it's hard to do anything real time on a dual core ESP32 running on top of an RTOS. The good news however is that it has 8 RMT channels which are designed to handle precise signals like this without tying up the CPU. See this code that supports Neopixels with exact timing: https://github.com/MartyMacGyver/ESP32-Digital-RGB-LED-Drivers
This is a 25mn mashup of all the video clips, including a section on flashing the arduiny via ISP (AVR 328p):
I also have a video showing the evolution of lights on my shirt from v1 (single non controllable color) to v2 (tri color, but not pixel addressable), to neopixels with cool patterns (jump to 3:50 if you'd like that):
While I was barely back from a ski trip and jetlagged in the wrong direction, my friend David (DJ Blur) encouraged me to come, for what was a great evening, starting with his own set. I was indeed tired that evening, but it was still worth the trip, great music.
I had seen Solarstone once before and he had done a great set at Dreamstate. Then, he did another 5h open to close set at Verso not a long time ago, but I totally missed that one due to poor planning. This time, I made sure to get my tickets early, and ended up going even after finding out my company Xmas party ended up being the same evening (darn), and I did not regret it: Solarstone threw a fantastic set, it was just good stuff up to the end:
And at the end Solarstone was super nice and came out to meet and greet. He loved my shirt and nicely took a picture with me:
I also have to give another big thumbs up to Verso. Not only do they get good DJs, but they have the least about of BS for getting in. Compare with places like Pure Lounge in Sunnyvale, where they first do a weapons search, which is annoying but potentially understandable, however when they do a drug search looking everywhere, even within the pockets of your wallet, this is totally pointless and a great way to turn off your customers.
Moral of the story: Verso: great, Pure Lounge: Bad. Hopefully Pure Lounge gets the hint and losens up. I told them, tell them too, and in the meantime, keep going back to Verso only instead :)
And here is a 30mn summary of the 5H set:
I had never been to Pure Lounge in Sunnyvale before, a short-ish drive from home, and Aly and Fila (really only Aly, Fila doesn't seem to travel to the US), was a good excuse to go. Pure Lounge sadly has a pretty ridiculous search at the entrance, and seemed to say that you could not even take small point and shoot cameras inside? What on earth is that?
That being said, once inside, it was a good evening, good set from Aly: