I am using the following circuit to measure the power consumption of a Raspberry Pi 4. The devices used are:

• A microcontroller such as ESP32, Arduino, etc. Here, I am using ESP8266 because it is available.
• An AC module: PZEM-004T
• Power outlet and plug

Below is my wiring setup:

• Download the Arduino IDE (I used version 2.3.4).
• Follow the ESP8266 board installation guide: ESP8266 Arduino IDE Setup
• Install the PZEM-004T library in Arduino IDE.
• Select the correct COM port to upload code → Choose the correct board (ESP8266, NodeMCU 1.0).
• Clone my .ino code, edit your Wi-Fi SSID and password, then compile and upload.

• Download Arduino CLI:

curl -fsSL https://raw.githubusercontent.com/arduino/arduino-cli/master/install.sh | sh

• Move arduino-cli from your personal directory to a system-wide directory:

sudo mv ~/bin/arduino-cli /usr/local/bin/

• Add your user to the dialout group to access serial ports:

sudo usermod -a -G dialout $USER

• Initialize Arduino CLI configuration:

arduino-cli config init

• Add the URL so Arduino CLI can fetch the ESP8266 Board package:

arduino-cli config set board_manager.additional_urls https://arduino.esp8266.com/stable/package_esp8266com_index.json

• Update the board and core index:

arduino-cli core update-index

• Install ESP8266 Arduino Core (includes toolchain, libraries, compiler):

arduino-cli core install esp8266:esp8266

• List all installed cores (ESP8266 should appear here):

arduino-cli core list

• List all connected boards:

arduino-cli board list

• Install the library for the PZEM-004T module:

arduino-cli lib install "PZEM004Tv30"

• Enter your Wi-Fi SSID and password, and fill in the IP address of the server you are hosting (where server.py runs) in the estimate_power.ino file.

• Then, compile file .ino in your folder:

arduino-cli compile --fqbn esp8266:esp8266:nodemcuv2 <folder-containing-.ino>

• Upload the compiled code

arduino-cli upload -p /dev/ttyUSB0 --fqbn esp8266:esp8266:nodemcuv2 <folder-containing-.ino>

• Open the serial monitor to view data from ESP8266:

arduino-cli monitor -p /dev/ttyUSB0 -c baudrate=115200

python3 server.py

After running, the power information of the Raspberry Pi 4 will be sent to the server continuously, with updates occurring approximately once per second.