Hello,
I am building a simpit and need some help locating hardward for it. I need to find screens for the numbers marked in the upload. Presently, I have been looking at OLED I2C's with the plan to use a multiplexer so one Nano can control them all. However. I am having a hard time finding anything that work for (see image) #1 and #3.
I was thinking of using a 256x32 OLED I2C but that is just a guess to the size I need.
Any help getting in the right direction would be great.
Thanks
I think the size of the display in mm or inches will be more important to you, not so much the size in pixels.
If you can use OLED with SPI, instead of i²c, you will not need a multiplexer.
If you cannot find green OLED, you could use white and put a green filter over it.
It's not clear which display "3" is meant to be.
Hey PaulRB!
Thanks for responding. I am new to all this, could you explain to me how I can use 1 Nano with SPI to support 8 screens? If I am able to that's great! I really liked the multiplexing deal, cool stuff!
Yes, I have seen that using a green filter would work with white lettering which is great!
#3 Are 5 additional screens with buttons next to them.
Take a look at this SPI OLED:
There are more pins than there are on i²c displays. CLK, MOSI, RES and DC on each display can be connected to the same 4 pins on the Nano (CLK and MOSI pins on the Nano should be used for CLK and MOSI on the displays, RES and DC can be any other digital pin on Nano). But the CS pin on each display must be connected to a separate digital pin on the Nano. By setting the CS pin to LOW for one display and HIGH for the other displays, the Nano can update that display without disturbing the others. "CS" stands for "Chip Select". Only the display with CS set to LOW will respond when data is sent from the Nano. The other displays with CS set to high will ignore the data.
Another option to consider could be 7 and 14 segment led displays. You can drive these easily with HT16K33 modules.
I think the main problem you will run into when connecting more than one such display to the Nano is the lack of memory. Nano has only 2 kb on board which is barely enough to run one display.
Choose another board to control displays - for example, rp2040 raspberry pico or esp32
@lowlyslows having worked with the real thing (RAF Jaguar) and also lab rigs for the same aircraft, I would suggest you start out by working out what each display needs to show.
For example, your display #1 looks to be a radio frequency display which would only be expected to display the digits 0..9 and a DP. A simple 7 segment display x6 would suffice and can be easily driven by a MAX7219.
If you need to display letters, then the alphanumeric LED modules that @PaulRB showed you work.
OLED modules generally come in specific sizes and may not fit the available spaces. They also have a larger memory overhead on the micro than simple LED modules.
You also need to decide how authentic looking you want your panel to be. Do you want/need the look of the individual "dots" on each bar of the 7 seg display? For example, with your display #1, we had something very similar on the Inertial Navigation display. They were individual plug in 7 segment modules - each one about 2in deep. One of my colleagues spent some time disassembling them to repair/replace the individual bulbs inside them!
Does display #2 only display 1 or 2 characters? An alphanumeric display would work here too.
I would also add that the reliability of OLED displays can be a problem. They are very fragile and fade with prolonged use.
I think it should be possible to share memory between the OLED displays, so that the Nano's memory would be enough. This might be tricky, however, especially for a beginner, and a board with more memory would make things easier. A Nano Every had has more memory but same size as "classic" Nano.
you should come up with a definition of the needed characters, digits, and physical size for each display.
Furthermore if you need this dot style font or if you would accept a 14 segment/7segment LED display.
Finally imho the available budget will limit your decision, so you should define also how much you are willing to pay for one display. Green VFDs may be still available - just not cheap to handle.
Since @lowlyslows would need HT16K33 to drive the 14-seg displays, it would make sense to use HT16K33 to drive the 7-seg displays also, rather than mixing two different chips.
PaulRB,
I thing the segment screens are the way to go with the ODU image #3. Through another user on FaceBook I found the actual displays. They are 16 segment 4 digit displays from tek creations: F18 Hornet Option Display (tekcreations.space)
I still need to figure out #1 and #2 but this is a good start. Big issue I need to figure out with the #3 is how to wire them up. Code is next.
Would the TM1640 work?
ask yourself:
How many cathodes do you need per digit (per common anode)?
How many cathodes per digit can the TM1640 drive?
Check the datasheet of the display about amperage of each LED, may be you could combine the segment A+B and E+F and use it just as 7 segment ... in this case the TM1640 might be useable for numbers and a limited set of characters only.
42?
No. HT16K33 is the only 14/16-segment driver chip I know of, and it has 16 pins for anodes and only 8 pins for cathodes. Your displays have 16 (actually 17 if you include those extra segments) cathodes and 4 anodes. So the driver does not have enough cathode pins.
EDIT: There is also MAX6954, but
Drives Common-Cathode Monocolor and Bicolor LED Displays
I cannot think of a way to drive one of those displays that is easy enough for a beginner to build, certainly not 5 of them plus other displays. I recommend you find other, common cathode displays.
The single-digit display looks much easier to deal with
You could use max7219 to drive 4 of those, or HT16K33 to drive 8 of them.
Could you build your displays using multiple single-digit displays?
Thanks everyone for all the help. I have a ton to learn. I am not seeing what you guys are seeing and need to spend some time learning how to read the diagrams and fully understand the difference between common cathode and anode. I hate to waste your time and effort due to my noobness.
A gentleman that is also building the same thing that I am has suggested the kit that I purchased and then last night suggested the TM1640. He has gotten it to work, see youtube video. I don't fully understand the schematic. I see 1 x Nano, 3 x TM1640s, 5 x buttons, and the 5 x 16 segment displays. All the other stuff, no idea yet. Maybe diodes and/or resistors? Not sure why they are there yet.
Very excited to learn and make this work! Cheers
sorry, I mixed up the TM1640 and TM1637.
Based on the datasheet it might work with the TM1640 and the 16 segments of the common anode display connected the segments to the "grid outputs" and the digits to the "seg outputs"
