radhive 
1. Introduction PlantLab is a beginner-friendly, open-source IoT plant care system built around a simple principle: use easily accessible, off-the-shelf modules—most of which you can buy on Amazon or AliExpress. No custom, hard-to-source parts, just affordable, ready-made modules and regular components. The purpose of the PCB is to link these modules together with connectors and … Read more
This is the second part of my article “A Homemade AZ/EL Antenna Rotator for Ham Radio Satellite Communication“. In the previous part, I introduced the project from its hardware perspective and mechanical structure. Today, we will center on its software concept, setup for use, and its known problems. Software Flows Upon power-on, the setup() function … Read more
When doing the field radio operation, the battery is always one of the things I care about most. For a small QRP station, the power problem is usually not very difficult. The current is low, and a modest battery could last for a long time. But I do not always run QRP. Sometimes I want … Read more
Welcome back to our Electronics Basics series. In the previous lesson, we explored voltage, current, and resistance. This lesson focuses on the two main forms of electric current you encounter every day: direct current (DC) and alternating current (AC). Their essential difference is direction. Conventional current in a DC circuit flows in one direction, while … Read more
Welcome back to our Electronics Basics series. In the first two lessons, we learned about electrons, electric charge, static charge, and electric current. Now we will explore three fundamental electrical quantities—voltage, current, and resistance—and see how they work together. We will use a water-pipe analogy to make the ideas easier to visualize. Like any analogy, … Read more
Introduction I got my first ham radio license in 2000, but it was 24 years later before I made my first satellite QSO with a U7V4 cross yagi mounted on my homemade AZ/EL antenna rotator. For years, I had known how much fun satellite operation could bring to a ham radio operator, but I never … Read more
Tired of Re-flashing Your ESP32 Just to Change WiFi or Fix a Web Page? If you have built any ESP32 or ESP8266 project with a web interface, you have felt this pain. You hardcode your WiFi credentials into the sketch, upload it, and everything works great until you need to change your WiFi credentials. Then … Read more
Disclosure: This is an independent introduction to SmartChamber-3D by maker ‘physton’. I am not the author of this project. The goal is to help makers decide whether it is worth studying, adapting, or building. Overview SmartChamber-3D is a chamber temperature control system for enclosed Bambu Lab P2S or P1S 3D printers. According to the OSHWHub … Read more
A More Efficient Antenna Is Needed for the Base Station To improve my Meshtastic base station’s ability to rebroadcast weak LoRa packets, I decided to replace the commercial “rubber ducky” coiled antenna with a homemade J-Pole antenna. While rubber ducky antennas are convenient for handheld devices, they are much less effective for a CLIENT_BASE node. … Read more
Ham Radio Tools SWR & Return Loss Calculator Convert between SWR, return loss, reflection coefficient, reflected power ratio, and mismatch loss. Add forward power when you want reflected watts and net power at the measurement point. SWR and reflected power diagram A transmitter sends forward power through a feedline to an antenna, with a smaller … Read more