Here, the Arduino Mega 2560 is used as the main control board to detect the value of the matrix keyboard press, control the 8X8 dot matrix and LED display, but you can also use other Arduino motherboards, because the programs can be used universally. If you want to control other devices, just replace the LED with the corresponding device. If you want to control the high-power device, just add a relay control.
1.Dot matrix display
1. Mega 2560 board
Input voltage (recommended):7-12V
Input voltage (range):6-20V
Digital IO pin 54 (16 of which are used as PWM outputs)
Analog input pin:16
IO pin DC current:40 mA
3.3V pin DC current:50 mA
Flash Memory:256 KB (ATmega328, 8 KB for bootloader)
Working clock:16 MHz
2. 8X8 dot matrix module
The MAX7219 IC is a serial input/output common-cathode display driver that interfaces microprocessors to a 7-segment numeric LED displays of up to 8 digits, bar-graph displays, or 64 individual LEDs. For convenience, here an 8×8 LED matrix, integrated with a MAX7219 IC setup, available as a pre-wired module is used. Typical specification of this LED Matrix Module is shown below:
Operating Voltage: DC 4.7V – 5.3V
Typical Voltage: 5V
Operating Current: 320mA
Max Operating Current: 2A
3. Matrix keyboard
Keypads are used in all types of devices, including cell phones, fax machines, microwaves, ovens, door locks, etc. They're practically everywhere. Tons of electronic devices use them for user input.
At the end when all is connected properly and programmed, when a key is pressed, it shows up at the Serial Monitor on your computer. Whenever you press a key, it shows up on the Serial Monitor.
4. LED X9
5. 220R Resistance X9
6. Breadboard X1