Introduction: PC Hardware Monitor With Arduino and ST7920 LCD

There are 2 versions of the project:

  • 4 numeric fieds and 1 graph for CPU load or clock
  • 4 independent graphs for CPU temperature, load, clock and used RAM


  • Arduino Nano or Arduino Pro Mini with USB to serial adapter
  • ST7920 128x64 LCD



Arduino + ST7920

Step 1: Connections

There are only 6 wires necessary to connect Arduino and ST7920 LCD in SPI mode.

Full list of connections from LCD side:

  • #01 GND to GND
  • #02 VCC to VCC (5V)
  • #04 RS to D10/CS or any pin
  • #05 R/W to D11/MOSI
  • #06 E to D13/SCK
  • #15 PSB to GND (for SPI mode)
  • #19 BLA to VCC, D9 or any pin via 300ohm resistor
  • #20 BLK to GND

To avoid extra GND lines solder 2 wires directly on LCD PCB: GND to PSB to BLK

Step 2: Arduino Firmware

Step 3: PC Software

  1. Download and install HardwareSerialMonitor

  2. Start it with administrator rights
  3. Choose correct serial port

Step 4: Demo Video: