WEB Power Interface

All power for my QO-100 satellite transceiver is made from a small solarplant in my garten. 3 solar panels of 250 Watt are feeding a battery in the garten house. The battery can make 240 Volts with a 3 KWatt inverter so that my “robby” and 2 water fontains are powered. In the summer we also have power in our garten pavillion.

I’m not powering the transceiver all the time – only when it is in use, so I was a little bit tired of going out to the garten house every time I want to use the transceiver from my computer inside the house. The goal was to make it remotly controlled as my other equipments for HF / VHF and UHF. This gives me the ability also to use it when I’m on hollyday – when it is needed :-).

I want to see what the voltage condition is of the solar panels and also see what power the battery has, so that I’m not using to mush power. At the moment, this has not happened even in the winter time.


There is internet in the garten house that is used for the Transceiver and is powered from the battery all the time.

I wanted to make a mikrocontroller, that is making a webpage on the locale network. That webpage can also be send to the internet with a forward in my internet controller.
Following criterias has been done:

  • All the time it will show solar voltage and battery voltage to get a overview of the plant state

  • On the website there are 2 switches to activate power to the Transceiver and the Power Amplifier (12v and 24V)

  • Both switch outputs are monitored so that voltages are shown for each of them

  • On the box of the remote unit, there are 2 switches with LED state indication, to activate / deactivate the outputs which are shown on the webpage

I have made some projects in the past with Arduino, and the easiest solution is with a ESP8266 D1 Mini that is small – can easy handle a webpage and has the outputs needed to get it done. On the internet there are several relay units for sale that are made for Arduino, and my choice was a small unit with 2 relays. To get a good voltage reading, there is also a small board called ADS1115. It can handle 4 inputs with I2C / 16 bit – and all 3 boards are using small power. Next I will show the schematic and the mounting in a small box.



The mikrocontroller is a ESP8266 D1 Mini that is powered on 5V delivered from a 7805 Voltage regulator. On the D1 Mini there is also a 3,3V regulator that is powering the ADS1115 board.

All components are mounted on a veroboard but if needed I can later make a PCB layout. To control the outputs near the interface without starting PC, there are 2 switches on the top of the case to manually change the outputs.


The interface is mounted in a small 12 x 6 x 4 cm plastic case. Up left I have mounted 2 connectors for in and output of power. Between them, is the LED for Power. To the right are the 2 LED’s showing output states. Down under that – the corresponding swithes for output 1 and 2.

I have soldered the connections on the connectors so that nothing happens when they are connected the wrong way. But else you could use other connector types instead with different pin numbers, that I did not had at that moment. Be sure to put fuses on all inputs so that nothing happens. I did it with fuses on the wires to the battery unit.




The schematic is not special and all is controlled by a ESP8266 Mini D1. The 5 Volts are generated from a 7805 with capacitors for stabilization. Power is taken from the solar battery. Outputs are inverted with transistors to convert the 3 volt from D1 mini to 5 volt which the relayboard need as input voltage to work correct. Input switches are pulled up with 10 Kohm resistors and are controlled with software to avoid contact bounce. LED’s on the relayboard are taken of the board and mounted on the front of the case instead.




This is a block diagram of the connections in the garten house. It shows how the solar power is saved in a battery and converted to 12 and 24 volts with some power supplies. The microcontroller is switching the 12 and 24 Volts to the transceiver for QO-100.
Update: Solar battery is changed to 24 V for better performance, so 12 -> 24V inverter has been removed and now used in my caravan instead, because there is still 12V :-).


All description on how the software works – are inside commented in the .ino file. Maybe you can use it for other things with small changes 🙂

Software and schematic for the microcontroller ESP8266 can be downloaded here: