Hi, I am trying to figure out how to use the Sparkfun Bubble display (see here) with a Partilce. On an Arduino it can be used with the Seven Segments display library. Has anyone used this display successfully on a Particle? Any suggestions on libraries to use?
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Sorry. You are right, I have edited the post by fixing the link.
@hbierau, before you consider using this display, you do know fact that it will require 12 GPIO pins on the Photon to work, right?. The Arduino Seven Segments library can be used if ported. The porting is not too difficult and I would be glad to assist.
Wow, that’s a seriously old-school LED device. Most LED displays now have I2C/SPI/Serial controller attached so they don’t require 12 GPIO lines and constant attention to control a 4x 7-segment display!
In addition to porting an Arduino library you could just write it from scratch. It might be fun, depending on your view of what fun is.
Basically, you need to loop so each digit gets updated at least 30 times a second or so. You set that digit’s cathode to output and low. Set the other cathodes to input, so they’re not driven. Then set the 8 anode pins for each of the segments of the digit to the appropriate state (high = on, low =off) so the correct digit is lit up. Then, several iterations of loop later (checking millis() would be good, to wait about 5 milliseconds), handle the next digit. Then 5 ms. later, handle the next digit. And so on, forever.
Unlike the much more useful modern displays with a built-in controller, you need to keep this one running updates continuously!
And don’t forget to add 8 current-limiting resistors between the anode pins and the Particle GPIO pins.
@peekay123, I am aware of that, but thanks for pointing it out. I know it is kind of a waste, but for the device I have in mind will be on an Electron, so there will still be enough pins that will remain for other purposes (e.g. buttons). I am not a complete beginner with micro-controllers (more experienced on the Arduino side though), but porting a library is still a bit advanced for me. So I would gladly accept your support on this (not sure how much I can help there).
@rickkas7, yes, it is old-school, but looks cool too (maybe because it is old-school). Thanks for hints regarding the workflow to implement.