Spi 1306 Screen jumping around

Hi. I have been able to get my first home made Arduboy going. It works fine with games like Wack a Mole and others with simple graphics. However, when trying to run Mystic Balloon or Castle Boy the screen jumps all over the place.

These are the settings I am using with an official Pro Micro.

Does anyone have any suggestions for a larger screen with a reasonable price tag?

There is no such thing as an official Pro Micro. Do you mean Arduino Micro? I assume you do as looking at yourt screenshot you’ve selected Arduino Micro as board. For a Pro micro you’d need to select Pro Micro Standard wiring/alternate wiring option.

This shoudn’t cause problems with display though. You could try changing the core to standard.

I’d say double check your wiring especially the OLED CS one. When there’s a bad or no connection. they display tend to jump

more details of your homemade Arduboy, an image of your wiring or a video clip of the jumping effect may be helpful too

Well, the “official” original Pro Micro was designed and is sold by SparkFun. It’s been cloned many times, often with minor layout, circuit, and component changes but they all appear the same from a software point of view.

It’s different than an “official” Arduino Micro.
(which has also been heavily cloned.)

Ah! Thanks for the info Mr. Blinky. I am very new to Arduino. Looks like by board is a copy of the Sparkfun one then.

I have tried changing all of the settings options linked to the home made board. No change. I pulled out the CS connection for the screen and it started to flick from one side to the other. This was a different type of effect to what I have been getting.

Not sure if this clip is working.

Oh. Seems to be. Here is how it looks on other views.

As you can see seems fine on simpler games. Just goes to hell on the more intensive ones.

This looks potentially like some issue related to the clock signal? but not really, as it’s not actually wiping the screen.

To be honest it kind of looks like the display controller chip, the ssd1306 is FUBAR some how?

Either that or there is some kind of digital interfence interference to the MOSI line?

In yourvideo/picture It looks like the display GND pin isn’t wired up. Is it connected to GND?

It looks like there’s a short bare jumper to the ground rail at the top of the breadboard.

The actual contents of the display are stable. It’s the OLED pixels themselves that are flickering on and off. This tells me that the signals and control of the display, and the RAM and control logic of the display’s on-board SSD1306 chip are working properly.

The problem is likely with the high voltage power supply for the OLEDs, which is generated by charge pump circuitry in the SSD1306. It could be connections or circuitry internal to the display itself or the required external capacitors on the module or their wiring. If you have a oscilloscope available you could probe the Vcc pin (28) on the display’s flex cable, to see if it’s the proper voltage and stable.

Anyway, I suspect it’s the display itself that’s bad and not anything to do with the wiring, Pro Micro, or software. Replacing the display module with an identical one would be the easiest (but expensive) next diagnostic step.

To me it looks like that jumper goes to VDD pin of display.

For future reference, you can use Alt+Print Screen to only screenshot the active window.

(Though that might not work with menus open, I’m not sure.)

I must have glossed over @bateske’s post. Yes, I think a noisy or intermittent MOSI (the SDA pin on the diplay) signal could cause the problem.

Sorry, I must be half asleep this morning. You are correct. (I was counting the pins wrong.) A connection to the GND pin can’t be seen, so it may be open.

Yeah kinda looks like floating ground.

Thanks for input everyone. Back at work after lock down so been head down. Will be having a look at your tips and pointers as soon as I get a chance.