Just took a JAVA update
When the Windows Arduino IDE is running, the javaw.exe uses approximately 35% CPU usage.If left unattended, it will never drop.The high CPU can be stopped by click File\Save (discovered by WacKEDmaN).The high CPU can be started by click moving or resizing the Arduino IDE window.
If I rename the java folder I get the error...
This may explain why most people don't see this bug. It is isolated to portable installs.
Stopping and starting:The high CPU can be stopped by click File\Save (discovered by WacKEDmaN).The high CPU can be started by click moving or resizing the Arduino IDE window.Anyone that already his this fault is welcome to reproduce these finding and confirm it or provided an alternate view.
Closing as fixed by updating bundled JREs
Westfw, thanks for giving me a nudge in the right direction!I had a look, and the Arduino IDE contains \java\bin\javaw.exeCompiling a list of java versions supplied with IDE versions reveals that IDE 1.8.6 and 1.8.7 share the same version of java. Arduino IDE version: 1.8.1javaw.exe version: 8.0.1110.14Arduino IDE version: 1.8.5javaw.exe version: 8.0.1440.1Arduino IDE version: 1.8.6javaw.exe version: 8.0.1710.11Arduino IDE version: 1.8.7javaw.exe version: 8.0.1710.11Arduino IDE version: beta 1.9javaw.exe version: 8.0.1910.12Arduino IDE version: Current hourly buildjavaw.exe version: 8.0.1910.12I then copied the java folder from IDE BETA 1.9 into the IDE 1.8.7 install folder and the fault is gone!As a double check, I copied the java from 1.8.7 into beta 1.9 and the fault shows up in beta 1.9.My conclusion is that the java supplied with Arduino IDE 1.8.6 and 1.8.7 (java version 8.0.1910.12) is the cause of the 30% CPU utilisation issue that some of us have seen.SOLUTION:You can run Arduino IDE 1.8.7 successfully simply by replacing the java folder, using the Arduino Beta 1.9 install as the source.Does anyone (that has seen this fault before) care to test and confirm or deny this theory?Cheers,Matthew.