The improvements of H4M:
Single power on/off switch. When powered off, the battey will no longer phantom drain, i.e., the device can be completely powered off.
Advanced battery management IC and battery display (battery %, voltage, current/draw, etc...). It is easier to check the battery level.
Matte screen. This matte screen can help you see the content of the screen much more clearly in sunny places outside.
360-degree Knob Button. The knob button becomes to be the flat design, going back to the ipod style click wheel. The knob is more convenient to use.
The GPIO port! This new generation H4M adds a GPIO port so users can make their own add-ons for the H4M, just like the flipper zero. This is a big step forward, and it's a design that hasn't been in any previous version of Portapack.
Improved charge speeds. The H4M improves the charging quality and speed.
Built in microphone and switch toggle. And there is a toggle to switch between the Built-in and the Headphone Microphone.
Automatic switching of sound between the headphone and the speakers. Once you plug the headphone, the H4M will automatically switches from speaker mode to headset mode. This is also a feature that the previous Portapack did not have.
