After building the NanoGrids I was still looking for a nice drum trigger sequencer. I want to have a bit more control over the drum’s then the Grids is giving. And stuck in my room with Covid I started designing something. There are a few modules out there that you can buy/build. Some really nice one’s also.
The Story
A few weeks back i got sick and had to spend a few weeks in isolation. Maybe I was lucky because I didn’t get really sick and I was in a room with my computer, Kicad, Arduino’s and breadboards.
I was thinking what was missing from my eurorack and I always liked the Roland drum programming on my MC-303. I needed something like a step sequencer for my drums.
There are some out there, just to name a few: Triggerhappy (diy), Erica Synths drum sequencer (about 550 euro), Robaux SWT16+ (my fav), BigButton (lookmumnocomputer) and lots more. Still all didn’t do it for me and I wanted something a bit different. At this point I didn’t know what I wanted so I just started building something. What I did know was I needed buttons lots of them.
I wanted to build Dotty (just give it a name) with cheap parts, Arduino, led’s a few resistors, maybe some cheap dip package chips and easy to build. These where my starting point one day later it came to this.
![](http://www.quinie.nl/wp-content/uploads/2020/10/20201009_201412-1024x768.jpg)
The Leds became Led dot Matrix. These you will find on ali, ebay or other sources. A Arduino Nano and 16 buttons. It looks rubies but it works, well kinda.
The next few day’s I started programming code in Arduino Ide. Making some basic functions, using the led matrix to display it all. I now could set step, clear them and some other nice stuff you would expect from a sequencer.
![](http://www.quinie.nl/wp-content/uploads/2020/10/Knipsel2.png)
When writing the code I started thinking about other functions. This lead to …more buttons. I was starting to reach the limits of the Nano. It only has a few pins. There are some devices out there that can extend these pins.
A was wrapping my head around all options, and made a few decisions. And after a few days of coding, more prototyping on breadboarding it came to this.
![](http://www.quinie.nl/wp-content/uploads/2020/10/20201011_141007-1024x768.jpg)
More buttons.. But also trigger out to test respond time of the Arduino. This was the last prototype I build. I think most technical functions are proven, the code is basis alpha version. I thought it was time to make a pcb out of it.
The design of the pcb in Kicad took me a few day. Placing all the component, footprints, silkscreens and traces.
![](http://www.quinie.nl/wp-content/uploads/2020/10/Knipsel3.png)
The image is one of three boards. This is the control board. It shows 32 buttons, 8 leds, 2 jack’s in and 8 out and 3 led matrix ‘s.
These boards are production right now and I hope to get them in a week or so. If it’s like the NanoGrids I will take a few revision before releasing it someday. It’s a ongoing project and design, nothing is final.
But he there might be a new drum trigger sequencer in the near future with some features that might be fun to play with. So more to come and still a lot of work to do.