I've only looked at Arduino for about a year so I'm sorry if i don't know that much. The issue I'm having is with this H730 Display module the pdf of the module is below
www.sos.sk/a_info/resource/d/H730.pdf
so far the only thing that has worked is using this schematic
the output of the 555 timer does change the displays well for one pin.
the main issue i'm having is that i cant control it from my Arduino UNO (output pin set at high), as soon as i touch the output from the 555 timer to the display pins it changes but i cant control it. I have tried many things for example transistors to the trigger and the control but so far nothing.
i would really appreciate it if anyone can help me
"so far the only thing that has worked is using this schematic" What do you consider "working"? Are you able to toggle the display using a 12 v pulse from the 555 timer? Why do you want to do this or is your intent just to show that you can control individual segments? To control the segments, you don't need the 555 - you should be able to set and reset each segment just by connecting the appropriate display pin to +12.
The data sheet says a minimum of 9.8 volts is required. How is your Arduino providing this voltage? If you haven't addressed this, search for methods of using one of the methods to boost the output voltage. There are multiple alternatives including transistors, relays, etc.
I wanted house address numerals that could be read from the street. I cut a seven segment display out of 3/16" aluminum and then fit nylon into the segment holes to diffuse the LEDs that light them. Each digit is 5.5" by 9". I used 3 RGB LEDs per segment and used an Micrel M5450 LED driver to interface to my arduino. My address has four digits, so I made four of them. After doing all that work, I decided that it would look better if I used a single digit and displayed the house number sequentially.
The M5450 is an interesting driver but it's not compatible with my 12 volt outdoor lighting that powers the address sign.
I also can display other messages but, as you will be, I'm limited by the 7 segments. Even so, at Christmas I displayed "HoHo" and then the house number. At Halloween, it can do "Boo". If Ohio State ever wins a national championship, I'll display "OSU" and maybe the score.
If you want, I've got a file where I figured out the codes for various numbers and letters.
i might have been a bit slow but i just figured out that i can send 12v direct to the display module and use the GND from the power supply to turn the electromagnets. So i was wondering if anyone knows how i can control the GND part, i know i have to use a transistor NPN i believe, ive tried many different ways but the transistor just doesn't work. iv tried putting a 1k resistor between the base and the UNO and put the emitter directly to the ground and used the output from the collector to connect to the display module and that hasn't worked either.
I have also tried using the low output from the arduino and the GND from the Arduino and so far that doesn't work the display only changes from the GND of the power supply
In particular look at "Using a transistor as a switch" and read about the protection diode. Your display uses an electromagnetic coil that will generate back EMF like the relay coil in the reference. The protective diode is likely a good idea. For your circuit, I think "Choosing a suitable PNP transistor" shows the circuit you want to use.
