I think it could be great, to create a PCB that fits those displays. In the end it’s more flexible and even cheaper.
So, those displays will need some kind of circuit to run fine. I took a look into the spec-sheet and there are two schematics. One it for “Vcc generated by internal DC/DC” and the other one “Vcc supplied externally”. I wonder which one is correct in our usecase. I’d guess it’s the external-one?
Seeed-Studio has those displays in their PCBA service btw.
So, if there is a interest on this, I’d offer to create such a PCB and put the eagle-files online, so everybody would be able to create their own displays-panels with an easy connection to midibox.
But at first I need to make clear, which schematic is correct.
One of my displays was DOA, a problem with the connector cable. I tried to solder it, but it is a challenge. Not impossible, but you´d need a very fine smd soldering tip and steady hands. I failed! and ordered moar from mah favourite Swedish supplier!
I saw that someone in China on Aliexpress had carrier PCBs you can buy. If those contain the necessary 2.8V power circuit they could be used. On the other hand, it shouldn’t be impossible to work with those FPCs either.
Then again, the MBProgramma application uses 4-wire mode. There has to be some variant of these displays with just the pins necessary for that.
Okay. Than I’ll stick to the standard wiring for now. Changes can be done in the future.
Btw: SPI is not natively supported of Midibox, is it?
The carrier board wouldn’t bring any advantages. So. I’m still up for creating a layout.
Could anyone say which of those two schematics is the right one? I can post them later on just click on the link on the starter post and scroll down. It’s there.
This means that even if we tried to shave off a few dollars of the MBProgramma OLEDs, they would still have a pin connector with 1 row of pins. There’s currently no way to make them fit straight without being a little diagonal. But, it adds to the personality of it :pirate: Avast, ye scurvy dogs!
The full boards with OLED-combo is like 6$ with OLEDs already soldered - the OLEDs alone are like 3$ - what is the expected production cost of the boards? Do we need to solder SMD vreg components? My full board combinations also have 6 small smd caps, that might be necessary for filtering - that is quite an effort for a max of 3 $ saved. UNLESS, you can realize a better form factor, which benefits many projects, that is prolly why J had the Programma in mind, where we really are out of space!
Well, I think that the cost savings are minimal at best. However, if you made a special PCB with pinpads in the middle of the whole show you could make it almost as small as the screen. But, it’s a difficult endeavor. Also, that board would be a little thicker than today’s solution and that’s very critical too.
The other attack vector is then the LRE board itself…
It’s not for saving money. It depends on the size of the carrier pcb. If I create a pcb for just one display, I’d think we will be at about $1 / pcb or less.
What I want is, create a schematic with a working layout for one display. Duplicating this to add more displays is not a big deal after that. Everybody should be able to create a display board that fits their needs.
Maybe in the future it makes sense to step back from the LRE. It’s very time consuming to solder all leds.
I’m right now in creating PCBs for encoder and led rings. It has two rows with each 4 encoder on it. There is enough space to place a oled underneath every encoder and the LEDs are soldered at the manufacture.
That’s why I need the right schematic. So any hell would be very appreciated.
Hawkeye: pls take a look at the sheet of the oled. There are schematics that show the parts needed. There also the filtering caps inside.
There’s a link in the MBProgramma thread to Aliexpress. However, it gives me a 500 code at the moment, there’s either an issue here at work, or some web host is affected.
yes, there is no vreg on the board - the displays work fine with the 3.3v supply of the core
edit: a design topic, so the tastes may vary, i personally like the 45° angled OLEDs a lot. it is something differrent. yarr! So not much more need for space, but a better connection scheme would be awesome, maybe one that allows for easy connecting to a future MBLRE board
and ordered moar from mah favourite Swedish supplier! 
