Been having issues when using the COM-1144 7 segment display where it works fine with no issues and out of nowhere, it will just stop working. No pattern as to why it stops, but it just stops displaying. I can replace with a new one and it;s back to working again. It doesnt happen to every one of them, but just randomly displays quit working.
Ideas as to why?
Test the circuit and see if it’s being over-volted? Is it in sunlight, hot/cold, or moisture?
TS-Russell:
Test the circuit and see if it’s being over-volted? Is it in sunlight, hot/cold, or moisture?
No overvoltage, no exposure to direct sunlight as it’s used indoors, no exposure to extreme heat or cold or moisture either.
Those and/or vibration, EMF, sketchy power supply, etc are my only guesses 
TS-Russell:
Those and/or vibration, EMF, sketchy power supply, etc are my only guesses
no vibrations as the unit sits on a flat surface and not being moved around, no emf or ripple and psu that feeds the entire unit doesnt affect anything else, nor does the ldo that feeds mcu and display.
one thing i did just catch is that this little display board from sparkfun is not simply a plug and play device. uing 12c com, there are no pullups on it, so i have a revision of my main board thats coming with the sda/scl pullups, so we will see.
after looking at several i2c compatible devices, none seem to have them added. maybe add that to notes for new revisions of breakouts, etc to at least add pads for an end user to add them if needed (like in this case).
i wont know for sure if this resolves the issue, but time will tell…
That’s a reasonable theory; share what you discover here after!
I’m having a similar problem. I got a COM-1144 yesterday, connected to a Redboard. I successfully used the basic tutorial (Serial UART) from https://learn.sparkfun.com/tutorials/us … nt-display. Then I applied the code to my more-involved sketch and it was working great, displaying the value I wanted.
The Redboard is powered only by USB, so it shouldn’t be voltage-related like the OP found.
I added one more element to my sketch, to display a different variable based on a button press. The display stopped working. Hmm. I tried reverting to the tutorial sketch, and it doesn’t work as normal - the display reads only 0000. It doesn’t display the setup sequence at all.
I tried running this https://github.com/sparkfun/Serial7Segm … ands#reset but it had no effect. I have also tried leaving unpowered for a while, no effect - as soon as it’s powered on, the display shows 0000 and doesn’t respond to any of my code.
Any ideas?
Thanks.
Well nevermind… I just solved it by disconnecting the display unit from the circuit and reconnecting. Apparently powering off the whole set didn’t work, but removing the 7s display from vcc did.
Weird.