If I see it right, the regular 5V ATX supply-voltage is directly fed to the USB outlets. Uaaaaa, I see burning small copperpoor USB Cables taking the 30 Amps from the powersupply, when a shortage is made :-( You should implement some fuses urgend ! May be one polymer ptc fuse per USB socket. Regards Armin  

On many of the ATX power supplys the 5VSB is Powerfull ( >= 2A ). I have used it to power the Raspberry Pi and use one of its GPIO to Switch on the main Supply to power the heavy load. It is just another usecase for a ATX power supply in combination with a Raspberry Pi.

Changes: HHGui inherits most of the OBD2-Analyser NG firmware v1.13.0 changes, especially: - added support for the following PIDs:   0x69 Commanded EGR Duty Cycle/Position and EGR Error   0x6A Commanded Diesel Intake Air Flow (IAF) Control and Relative IAF Position   0x71 Variable Geometry Turbo (VGT) Control (commanded/actual position and status)   0x7F Engine Run Time, Engine Idle Time, PTO (Power Take Off) Time   0x83 NOx Sensor (NOx concentration for up to 4 sensors)   0x85 NOx Control System        average reagent consumption        average demanded reagent consumption        reagent tank level        engine run time while NOx warning indicator is activated   0x88 SCR Inducement System Actual State/History States of last four 10000km blocks        reagent level too low        incorrect reagent        deviation of reagent consumption        NOx emissions too high        system active state (current 0-10000km block only)        distance traveled in 10000km block while inducement system active compared with total distance traveled in 10000km block   0x8C Oxygen Sensor (Wide Range) for Diesel (oxygen concentration and lambda for up to 4 sensors)   0x8F Particulate Matter (PM) Sensor Output for up to 2 sensors        sensor actively measuring        sensor regenerating        normalized output value: 0% (fully cleaned/regenerated sensor) - 100% (sensor soot load level when sensor regeneration is needed) Bugfix: - fixed detection of second data byte B (corresponds with bank 3,4) in PIDs 0x06-0x09 and 0x55-0x58   This was broken in the firmware since v1.11.0 and in HHGUI since v3.20.Notes: Since some of these PIDs contain very long text acronyms, I decided to change the display layout in the Current Data and Freeze Frame Data menus. Apart from some rare cases, all acronyms and their related data fit into a single line now. So, I might switch to the new acronym names (see remark in previous update) in a later release. With the new PIDs, the Current Data and Freeze Frame Data menus support 266 data items now which no longer fits into 8bit. Therefore, the list handling for lists with up to 65536 list items had to be activated. This slightly increases Flash and SRAM usage for all lists. The text compressor for compressing the PID text descriptions got an update which will be released in the comments section of the OBD2 for Arduino project.HHGui installation and usage on the Pi: HHGui installation, usage and compile instructions are given in file Readme_raspberry.txt. This file is in the hhgui330_usr.zip file which also contains the HHGui binary for Raspberry Pi. The German PDF manual is also in this archive. There are two different hhgui binaries and two different libhhgui_pi.a files in the archives: For the Raspbian Buster September 2019 release, HHGui was compiled with gcc version 8.3.0 (Raspbian 8.3.0-6+rpi1) and linked with GTK+ 3.24.5. For the older Raspbian releases, HHGui was compiled with gcc version 4.9.2 (Raspbian 4.9.2-10) and linked with GTK+ 3.14.5.

Yet another update: OBD-Analyser NG / Handheld Open firmware V1.13.0 and OBD2 Software HHGui V3.30 Highlight: Added support for another 9 PIDs with more than 50 data items (sensor data, counters, ...)Changes: - added support for the following PIDs:   0x69 Commanded EGR Duty Cycle/Position and EGR Error   0x6A Commanded Diesel Intake Air Flow (IAF) Control and Relative IAF Position   0x71 Variable Geometry Turbo (VGT) Control (commanded/actual position and status)   0x7F Engine Run Time, Engine Idle Time, PTO (Power Take Off) Time   0x83 NOx Sensor (NOx concentration for up to 4 sensors)   0x85 NOx Control System        average reagent consumption        average demanded reagent consumption        reagent tank level        engine run time while NOx warning indicator is activated   0x88 SCR Inducement System Actual State/History States of last four 10000km blocks        reagent level too low        incorrect reagent        deviation of reagent consumption        NOx emissions too high        system active state (current 0-10000km block only)        distance traveled in 10000km block while inducement system active compared with total distance traveled in 10000km block   0x8C Oxygen Sensor (Wide Range) for Diesel (oxygen concentration and lambda for up to 4 sensors)   0x8F Particulate Matter (PM) Sensor Output for up to 2 sensors        sensor actively measuring        sensor regenerating        normalized output value: 0% (fully cleaned/regenerated sensor) - 100% (sensor soot load level when sensor regeneration is needed)Bugfix: - fixed detection of second data byte B (corresponds with bank 3,4) in PIDs 0x06-0x09 and 0x55-0x58   This was broken in the firmware since v1.11.0 and in HHGUI since v3.20.Notes: Since some of these PIDs contain very long text acronyms, I decided to change the display layout in the Current Data and Freeze Frame Data menus. Apart from some rare cases, all acronyms and their related data fit into a single line now. So, I might switch to the new acronym names (see remark in previous update) in a later release. With the new PIDs, the Current Data and Freeze Frame Data menus support 266 data items now which no longer fits into 8bit. Therefore, the list handling for lists with up to 65536 list items had to be activated. This slightly increases Flash and SRAM usage for all lists. The text compressor for compressing the PID text descriptions got an update which will be released in the comments section of the OBD2 for Arduino project.HHGui installation and usage: HHGui installation and usage instructions are given in files Readme_windows.txt, Readme_ubuntu.txt or Readme_raspberry.txt. These files are in the hhgui330_usr.zip file. The Windows executable of HHGui needs the runtime libraries that have been released with the HHEmu v2.80 release. The runtime libraries must be copied to a directory that is in the PATH environment variable or they simply must be put into the same directory than the hhgui.exe file.Developer notes: A makefile makefile_dev_hhgui, full sources of the emulator/simulator environment, some parts of the firmware (main/USART/LCD/SPI/GUI) and target dependent HHGui libraries (libhhgui_mingw32.a, libhhgui_msys2.a, libhhgui_ubuntu.a, libhhgui_pi.a) are supplied in hhgui330_dev.zip that lets you create your own version of HHGui. HHGui compile instructions are given in files Readme_windows.txt, Readme_ubuntu.txt or Readme_raspberry.txt.

See other variant at : https://www.elektormagazine.com/labs/sunlight-rejecting-opto-switch