HID info sender

Python script to add features to my QMK keymap for the Sofle RGB keyboard.

Features

Device utilization stats (CPU, RAM, GPU, Integrated GPU, Temperatures)
Date & Time
Control External Monitor Brightness & Contrast (via DDC/CI)

Works on Windows only. See byte format for the data format to port this to other OSes.

Setup

Install latest Python for windows. Make sure you have the py command/launcher available in your terminal.
Install HIDAPI
- Download the latest compiled dll and lib from libusb/hidapi releases
- On Windows, you will need to 'install' the .dll and .lib by copying the appropriate dlls to C:\Windows\System32. On 64-bit Windows, use the ones in the x64 folder.
Install Open Hardware Monitor (for CPU temp)
- Download the latest zip from openhardwaremonitor.org
- Run the .exe once with admin rights, make sure it works.
- Copy the OpenHardwareMonitorLib.dll from the install directory to the same directory as this script.
py -m pip install hid - this python package is a wrapper for HIDAPI.
py -m pip install psutil - For CPU usage.
py -m pip install pythonnet - For injecting the Open Hardware Monitor dll.
py -m pip install monitorcontrol - For external monitor control
Run the python script as admin. See Automated startup.

Automated startup

You will need to use a ridiculous hack to schedule this python script to run silently in the background upon log in, while giving access to external monitor brightness control.

Open Task Scheduler
Create a new task, name it something like "Forward HID Info at startup", or something memorable and indicative.
General tab: check Run only when user is logged on, and Run with highest privileges.
Triggers tab: create a new trigger, At startup, and make sure Enabled is checked.
Actions tab: set action to Start a program
- Program/script: C:\Windows\System32\cmd.exe (or wherever cmd.exe is located. Use where.exe cmd command to find out)
- Add arguments: /c start /min "" -ExecutionPolicy Bypass -File "C:\path\to\forward_hid_info.ps1". The \path\to\forward_hid_info.ps1 should point to the forward_hid_info.ps1 script in this repo. See explanation here
Test that the scheduled task works.
- In the right pane, click on "Enable all tasks history"
- Select the "Forward HID Info at startup" task in the list of scheduled tasks
- Click "Run" in the right pane.
- Check the history tab of this task and make sure the "Action started" task category is logged.
- If there's an error, it will show up in the "Last Run Result" column.
- Restart computer to check that the task runs upon log in.
After testing, "Disable all tasks history".

Note: To stop/restart the Python script, open Task Manager, search for 'py.exe', right click and select 'End task'. Ending the task from Task Scheduler doesn't work.

If there's an easier way to do this, please let me know. Things I have tried and didn't work:

The "Run even when user is not logged on" trick to run a powershell script in the background does not allow access to external monitor brightness control (security reasons)
Using pyw.exe instead of py.exe flashes a console window every 300ms or so (this has something to do with the OpenHardwareMonitorLib.dll injection)

Bugs

After flashing both sides of the keyboard, HIDAPI may throw the 'Device not connected' error, even if the keyboard is connected. To go around this, restart the script. In task scheduler, select the "Forward HID Info" script, click "End" then "Run".

Byte format

Fixed to 0x01 (identifies this custom data packet)
CPU utilization percentage
CPU temperature percentage (30-100C -> 0-100%)
RAM utilization percentage
GPU0 utilization percentage
GPU0 memory utilization percentage
GPU0 temperature percentage (30-100C -> 0-100%)
GPU1 utilization percentage
Placeholder (set to 0x00)
Placeholder (set to 0x00)
current month (1-12)
current day of the month (1-31)
current day of the week (0-6: Monday-Sunday)
current hour (0-23)
current minute (0-59)
current second (0-59)

Bytes 17-32 are unused. (HID reports are fixed to 32 bytes).

NOTE: In this implementation, an extra 0x00 byte is prepended to the packet to signify to windows/HIDAPI that it is a HID request packet, offsetting the bytes sent to the HIDAPI call. This extra byte does not get sent to the keyboard. This may or may not be necessary on other OSes/other HIDAPI wrappers/libs.