FantomXR Posted January 13, 2015 Report Share Posted January 13, 2015 Hey folks, in another thread those displays were mentioned: http://www.buydisplay.com/default/datasheet-128x64-oled-module-spi-0-96-inch-graphic-displays-white-on-black 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. Thanks, Chris Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted January 13, 2015 Report Share Posted January 13, 2015 Hi Chris, great idea! 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! :smile: and ordered moar from mah favourite Swedish supplier! ;-) Many greets, Peter Quote Link to comment Share on other sites More sharing options...
FantomXR Posted January 13, 2015 Author Report Share Posted January 13, 2015 SMD soldering is not a problem here. We could also let all SMD parts solder at the pcb manufacture and just put the display in. Anyway...I need the right schematic :) Quote Link to comment Share on other sites More sharing options...
jojjelito Posted January 13, 2015 Report Share Posted January 13, 2015 (edited) 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. Edited January 13, 2015 by jojjelito Quote Link to comment Share on other sites More sharing options...
FantomXR Posted January 13, 2015 Author Report Share Posted January 13, 2015 If you can guide me to the carrier pcb on alien press, this would be nice. My idea was not to create something that only works for MBProgramma but for all other applications. Do you have a wiring layout for using the SPI? What are the advantages? Quote Link to comment Share on other sites More sharing options...
jojjelito Posted January 13, 2015 Report Share Posted January 13, 2015 (edited) Here's an example of empty carrier PCBs on AliExpress: http://www.aliexpress.com/item/100PCS-LOT-0-96-inch-1-3-inch-OLED-adapter-plate-free-shipping/2031452713.html There are lots of variants. Better go for some facts-checking before I'll post a wiring diagram. Edit: I earlier assumed that 4-wire mode was SPI. Still think that's the case, but I'd better check the facts after work. Edited January 13, 2015 by jojjelito Quote Link to comment Share on other sites More sharing options...
FantomXR Posted January 13, 2015 Author Report Share Posted January 13, 2015 (edited) 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. Edited January 13, 2015 by FantomXR Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted January 13, 2015 Report Share Posted January 13, 2015 They are all driven in 4 wire SPI mode, 6800 / 8080 would imho need moar than necessary data wires. Currently, a SSD1306 needs 7 wires to wire and it is already some wiring! (Forgive me, too many solder fumes!) :hyper: Quote Link to comment Share on other sites More sharing options...
jojjelito Posted January 13, 2015 Report Share Posted January 13, 2015 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! Quote Link to comment Share on other sites More sharing options...
FantomXR Posted January 13, 2015 Author Report Share Posted January 13, 2015 Like i said: let's step back from the MBProgrammer. If we have a working layout which works fine with NG, other layouts can be easily adapted. Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted January 13, 2015 Report Share Posted January 13, 2015 (edited) But can you really save so much cash? 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! :-) Many greets, Peter Edited January 13, 2015 by Hawkeye Quote Link to comment Share on other sites More sharing options...
jojjelito Posted January 13, 2015 Report Share Posted January 13, 2015 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... Quote Link to comment Share on other sites More sharing options...
FantomXR Posted January 13, 2015 Author Report Share Posted January 13, 2015 (edited) Yes! You got it. 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. Edited January 13, 2015 by FantomXR Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted January 13, 2015 Report Share Posted January 13, 2015 (edited) Cool! I can take some high-def photos of the carrier board of the OLEDs. This should help, the wiring is not difficult, not a schem, but close! :smile: I have a disassembled one lying around anyways, the displays lifespan was not first-grade :-) Edit: the linked empty carrier != the current carrier, that is in use - where is the datasheet? Many greets! Peter Edited January 13, 2015 by Hawkeye Quote Link to comment Share on other sites More sharing options...
FantomXR Posted January 13, 2015 Author Report Share Posted January 13, 2015 I have 15 of those oleds by myself :-) But a schematic would be more safe. Quote Link to comment Share on other sites More sharing options...
jojjelito Posted January 13, 2015 Report Share Posted January 13, 2015 (edited) 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. Also, you can get some interesting data from the SSD1306 data sheet. Edited January 13, 2015 by jojjelito Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted January 13, 2015 Report Share Posted January 13, 2015 (edited) :-) If you look in section 1.6.2 "Block Diagram", vcc generated internally http://www.buydisplay.com/download/manual/ER-OLED0.96_Series_Datasheet.pdf ...the 6 caps and the 1 SMD resistor correlate with the current carrier, also the BS0-2 protocol selection lines. I think you have a good chance implementing it like this. R1 = 390k matches, just validated Many greets, Peter Edited January 13, 2015 by Hawkeye Quote Link to comment Share on other sites More sharing options...
FantomXR Posted January 13, 2015 Author Report Share Posted January 13, 2015 (edited) Thanks! Yes but I don't know if this is the correct one. Are you sure that I don't want to go with with "Vcc generates externally"-schematic? I want to start it today evening. Btw: If we go with this solution, it would be also possible to use oleds in a smaller size. Maybe this is a solution for your MBProgrammer? Edited January 13, 2015 by FantomXR Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted January 13, 2015 Report Share Posted January 13, 2015 (edited) 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 :-) Edited January 13, 2015 by Hawkeye Quote Link to comment Share on other sites More sharing options...
FantomXR Posted January 13, 2015 Author Report Share Posted January 13, 2015 Of course it looks kind of nice. But it will need special lables. Anyway: nice design. But that's covered in another thread. Quote Link to comment Share on other sites More sharing options...
jojjelito Posted January 13, 2015 Report Share Posted January 13, 2015 Ali Express link to the extant OLED choice: http://www.aliexpress.com/item/New-10x-3-3V-0-96-OLED-display-module-Arduino-compatible-128-64-White-Color-SSD1306/621502022.html There's a pinning diagram, a photo of the board as well as dimensions. Also, the SSD1306 data sheet gives the following: 4-wire SPI uses the following pins: D1: SDIN D0: SCLK CS#: CS# (labelled CS in the AliExpress data) D/C#: D/C# (DC) RES#: RES# (RES) plus of course: 3V3 GND So, just 7 things to connect, plus some things to strap. Better than all 16 pins. Quote Link to comment Share on other sites More sharing options...
FantomXR Posted January 13, 2015 Author Report Share Posted January 13, 2015 (edited) Okay, and as you see here: http://ucapps.de/mbhp/mbhp_lcd_ssd1306_single_mios32.pdf TK added a resistor and a cap too. //edit: See this schematic: BS0, BS1 and BS2 will go to GND and I would also ground every unused pin. Edited January 13, 2015 by FantomXR Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted January 13, 2015 Report Share Posted January 13, 2015 (edited) Yes, that is necessary for the correct "late" initialization of the OLEDs: after powerup, the cap is charged, only when it is full, the RST pin toggles its state from "reset" to "run". This filters initial garbage on the data lines and power fluctuations during the first milliseconds after power is available. You can use a shared resistor/cap for many displays for this (then 7 wires per display are required), or you can save one wire and mount it on the small boards with two cheap smd components. That would be indeed nice! And preselecting the 4-wire SPI mode is cool, too! :) Many greets, Peter Edited January 13, 2015 by Hawkeye Quote Link to comment Share on other sites More sharing options...
FantomXR Posted January 13, 2015 Author Report Share Posted January 13, 2015 I didn't get the last suggestion. What do you mean by mounting int on the small board? This looks nice too:http://www.exp-tech.de/sparkfun-redbot-kit The schematic is the same like the one on buydisplay. So this should work.... Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted January 13, 2015 Report Share Posted January 13, 2015 (edited) That sparkfun display looks nice! :-) The suggestion was to install the reset cap/resistor on the board you are designing. This saves one line (6 instead of 7) and also the users can forget about installing a cap and resistor somewhere to properly initialize their displays :smile: Many greets, Peter Edited January 13, 2015 by Hawkeye Quote Link to comment Share on other sites More sharing options...
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