In order to prevent my venetian window blinds to go down on timer in front of my open window-style terrace door, potentially locking me out, I needed to know if the door handle was in the “open” position. However, I did not want to use a battery powered radio sensor, but the existing door open/close magnetic sensor in the door frame. Here’s my solution.
This post is to share my self-made 3D printed housing for a 5V USB voltage converter. Since the used converter board is quite common, I guess others may profit from this design.
The installation of my fuel cell heating required a bi-directional power meter. Bonn Netz, my local power network provider, uses meters of type EasyMeter Q3M which have two infrared interfaces: A bidirectional D0 interface, and a read-only info interface. I use the info interface (INFO-DSS) to read out power consumption and production of the three phases. For this, I built an optical interface, a 3D printed housing for it, and use the UART of a Raspberry Pi with python to get the values.