The enormous development of electronics over the past decades has also affected our homes. The term Smart Home is no longer a stranger to anyone. Home Assistant undoubtedly has its place among the various Smart Home systems. 
One of the important devices in the production of printed circuit boards by the photo process is the exposure unit. Its construction, for radio amateur needs, is described in this article.
The huge boom in the production of electronics and its components also affects the work and creation of radio amateurs. New components bring new possibilities by improving functionality and expanding their capabilities. The reduction of chip sizes comes hand in hand with the reduction of case sizes and the introduction of new types. The vast majority of new parts and new cases are designed for SMT (Surface Mount Technology). The use of such components in radio amateur practice brings many pitfalls, one of which is soldering.
href="images/obr/reflow13.jpg">
href="images/obr/reflow13.jpg">
Inspired by the raspberry PI project https://bigpi.vc/build-a-simple-radiation-monitor-using-a-raspberry-pi-influxdb-and-grafana/ and previously published on github.
The main motivation for the implementation of this project was the lack of chips for the production Raspberry Pi boards. last but not least, their price. Most of Raspebrry Pi boards will be available maybe by the end of the year 2023, currently are out of stock over the world.
A simple Python application to measure, record and track background radiation in your area. Radiation is detected with a low-cost Radiation board CAJOE , and connected to a Banana Pi M2 ZERO SBC (BPI-M2). The board feeds data into the InfluxDB. Grafana is used for log appealing log visualization. Measured data are stored locally on the BPI-M2.
The basic equipment of every electrical engineering or model maker's workshop includes a mini drill, in the case of electrical engineering primarily for drilling printed circuit boards.
A seemingly simple operation, drilling holes, has its own hidden pitfalls affecting the quality of the drilled holes in subsequent operations, especially soldering, and therefore has an impact on the overall result. A frequent problem when drilling holes is the need to accurately guide the drill to the axis of the position of the drilled hole, which often slips due to surface irregularities (etching, lack of etching, missing recess for the hole, surface paint irregularities, etc.) into an unwanted position and we drill the hole where we do not want it, or when the drill slides at high speeds on the surface of the board, unpleasant scratches are created, which may not only be cosmetic in nature, but thinner conductive tracks can be damaged.