After hearing about the HC-12 operating distance over a kilometer, I wanted to test it by myself. What kind of information one sends is...

It is a USB charger that turn complacently off after 3.5 hours. After one presses the power button (the red one) a relay is turned ON and...

At the moment the FDM 3d printing industry is moving towards 2 print head system, or it is already there. The main issue with this...