MiniDexed DX7 in a keyboard

MiniDexed installed into the CME UF70 keyboard. Still running a very early version of the software, I will update the SD card tomorrow and check my hardware still works. It has some annoying traits as double click to enter and one to leave which is totally bizarre, but the developer thinks that is correct. The new version has performances, so in theory I can create 8 layer patches of DX7 with effects. It also has 128 banks of sounds onboard and I think that has been expanded too. I just loaded up the old favourites for a test.


Loaded up the latest release of MiniDexed this afternoon after the air raid sirens had ended and I have to say it’s a vast improvement on the release I was using. I now have performances that I can use to build layers etc. Seems to be a big improvement and the encoder button now works as it should with a single click to select, a long press for back and a double click for home.


A build of the popular MiniDexed DX7x8 FM synthesizer mounted into a used CME UF70 classic chassis. The latest release of MiniDexed was installed to utilize the performance features that allow for all 8 DX7s to be played from the keyboard to create amazing pads and sounds. Except for my lousy keyboard skills I’ve never heard FM sound so good.


What processor are you using?

It’s Pi based, you can use any Pi from a 1-4, the amount of Tone Generators will depend on the performance of the Pi, I’m using a PI-400 stripped out of its keyboard as Pi’s are hard to get hold of.

Details are here… GitHub - probonopd/MiniDexed: Dexed FM synthesizer similar to DX7 running on a bare metal Raspberry Pi (without a Linux kernel or operating system)


Yes, you only get one tone generator on a Pi V1, but 8 on the quad core 3 and 4. Can’t remember about a Pi 2…

That is looking (and sounding) great! Also it’s great to see the ssd1306 screen support I added being used “in the wild”!! :slight_smile:

Aside, the button operations are fully configurable in a whole range of different modes now - including using more physical buttons or MIDI CC/Note Numbers for the UI controls instead if that works for you.



Thanks but it’s not SSD1306, it’s a 1602 OLED, I’ve been using OLED displays since day 1.

In this system an SSD1306 would be far too small.

I thought about adding some navigation buttons but really I just wanted to get this up and running.


Haha - really? Np then! It looked like an ssd1306 OLED in that video to me - you seem to have managed a great level of contrast on that display. I’ll squint a bit more at it!! :slight_smile:

(I also did some work for I2C 1602’s so they can be hooked up with less wires. Hopefully that is proving useful for implementers too - my first build was a right spaghetti!)


Yeah I did look at that too, I had a spare i2c to LCD controller and I have used them in other projects. But this only needs 9 wires, 7 without power, and I’m not that desperate to save GPIO pins yet that I need to go down that route.

I was more pleased to have made use of my pi400 that’s been laying around for months and I watched a video on how to open them up.

So all my Pi stuff is being used now, but I need to get an micro SD card extender to finish it up or I keep on having to open it up to make updates.


All the contributions to the project are most welcome even if some of them seem quite bizarre and specific use cases to me.


IIRC a Pi2 can handle 8 tone generators but may have problems with running heavy effects on top of that.

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