China provides for a small price a huge amount of not only electronic devices, but also their components. A small matrix made up of light emitting diodes can show the information you need, presumably these are numbers, since the resolution is not very large, each with a diameter 3 mm. This matrix shines red, because it is most noticeable and attracts attention more than other colors.
It’s most convenient to use this matrix to manage, because it is digital. If you write a simple program, you can display the necessary information on this LED "screen". There are more expensive three-color matrices on sale, in which by combining the main three colors you can create almost any.
This matrix has 16 conclusions, the above diagram is shown where it is clearly shown how the elementary components of the matrix are connected - LEDs, guided by it you can correctly connect the module to reproduce information with both a digital and an analog device. Do not forget about current-limiting resistors, it will be sad if one of the pixels burns out. The rated continuous current of one point is 20 mA, peak forward current 100 mA, supply voltage 2.1-2.1Vwavelength 625-630 nm, the maximum power dissipation is 40 mW, the common anode is here, that is, a plus. Overall dimensions of the LED matrix on mm. It is necessary to solder carefully, do not touch the soldering iron with a temperature of 260 degrees for more than 5 s, recommended operating temperature -40 - +70 on the celsius scale.
If you have several such matrices on LEDs, you can connect them, creating large area information boards.
Cost: ~ 73