==== Power measurement tutorial with Hard Kernel power meter ====

=== PARTS NEEDED ===

{{:ixc2025:powermeter_parts.png?nolink&400|}}

  * A. Hardkernel SmartPower power meter
  * B. Power supply
  * C. PC computer
  * D. ESP32 Plus controller board
  * E. Special USB-C cable to connect board to the power meter
  * F. Two regular USB-C / USB-A cables

After connected together the setup should look like this:

{{:ixc2025:powermeter_setup.jpg?nolink&400|}}

=== HARDKERNEL SMARTPOWER LAYOUT ===

{{:ixc2025:smartpower3_layout.png?nolink&400|}}

  * A. Screen
  * B. Options menu
  * C. Power LED
  * D. Alive LED
  * E. Output channel 0 (left) on / off
  * F. Output channel 1 (right) on/off
  * G. UI selector, push to select
  * H. USB-C connector to PC
  * I. Channel 1 power connectors
  * J. Channel 0 power connectors
  * K. Power supply connector

=== PREPARATIONS FOR THE POWER METER ===

  - Connect the power supply to the meter
  - Connect the meter to a PC machine via USB-C cable (should be seen as "CP2102N USB to UART Bridge Controller" in Windows machines)
  - Download and install CP210x driver for virtual COM port from: https://www.silabs.com/developer-tools/usb-to-uart-bridge-vcp-drivers?tab=downloads
  - Download and install PuTTY SSH and Telnet client from: https://www.putty.org/
  - Check the virtual COM port from the Windows device settings
  - Open PuTTY and setup the connection
    - Session -> Connection type: Serial
    - Session -> Serial line: COMX (X = the number of the virtual serial port)
    - Session -> Speed: 115200
    - SSH -> Serial -> Flow control: None
    - Session -> Logging -> Session logging: All session output
    - Session -> Logging -> Log file name -> Browse button: Select suitable output folder for log file, set file name as Measurements&D&T
    - Session -> Saved sessions: Input name for your setting and click "Save" to use store the settings
    - Click "Open"
  - If everything is working correctly, you should now see measurement data coming from the meter in the PuTTY terminal window

=== PREPARATIONS FOR THE ARDUINO ENVIRONMENT ===

  - Connect the ESP32 Plus board to a PC via USB-C cable (detach the power meter cable if needed)
  - Follow the installation instructions: https://docs.keyestudio.com/projects/KS5009/en/latest/docs/Arduino/arduino.html#esp32-plus-development-board

=== GATHERING THE MEASUREMENT DATA ===

  - Have a stopwatch, pen and paper ready!
  - Connect the power supply to the meter
  - Adjust output channel 0 (left connectors) settings to USB 2.0 values (5.0V, 0.5A)
  - Connect the ESP32 Plus board to the power meter via modified USB-C cable
  - Connect the power meter to a PC via normal USB-C cable
  - Open PuTTY, load the setting stored in the preparations stage and open the terminal connection to the meter 
  - Activate the left output channel (channel 0) from the power meter
  - Use the stopwatch, pen and paper to manually log the key events during the testing (activation / de-activation time of the board, trigger times for the sensors etc.)! This helps you later to analyze the results
  - When the testing session is done, de-activate the left output channel
  - Close PuTTY window
  - If everything went well, you should now have a new log file (e.g. MeasurementsXX) in the folder you selected in the PuTTY settings
 
=== ANALYZING THE MEASUREMENT DATA ===

{{:ixc2025:naeyttoekuva_2025-01-18_111409.png?nolink&400|}}

  - Open the log file in a text editor
  - Delete non-data rows from the beginning and the end of the file manually
  - Import the file into Excel as csv / text file
  - Replace the header with the following information: Time (ms), In (mV), In (mA). In (mW), In (on/off), C0 Out (mV), C0 Out (mA), C0 Out (mW), C0 Out (on/off), C0 Out Intr, C1 Out (mV), C1 Out (mA), C1 Out (mW), C1 Out (on/off), C1 Out Intr, Checksum8 S2, Checksum8 XOR
  - It might be a good idea to add one more column where you calculate the elapsed time from the start of the measurement in seconds
  - Now you can play with the data! Create at least the following scatter plots: 1) Time (ms) vs. C0 Out (mV), 2) Time (ms) vs. C0 Out (mA), 3) Time (ms) vs. C0 Out (mW)
  - You can now analyze the plots by using the event times from the manual test log 

=== READ MORE ===

  * Hardkernel SmartPower power meter reference guide: https://wiki.odroid.com/accessory/power_supply_battery/smartpower3  
  * KS5009 smart home set / ESP32 Plus controller board reference guide: https://docs.keyestudio.com/projects/KS5009/en/latest/docs/Arduino/arduino.html#esp32-plus-development-board