CircuitGeek

You would like to create a LED Matrix, but the only matter is you don’t want to get too fussy with soldering each LED individually?
Well, there is always a good alternative here and it’s doesn’t costing you too much.

Those components that needed are:

Two 5×7 LED Matrix Displays
Solder Breadboard
Transistors
Resistors
4017 Chip (For switching in between the columns)
Wires, [...]

This circuit was a winner in Electronics Today International in 1987. Solid state oscilloscope is really simple and small size. Even it can be powered from tested circuit. Actually it has low frequency range (up to 500Hz) and low resolution (100LED matrix display).

Despite its poor parameters, circuit can be fun to experiment with cheap [...]