Arduino based MPPT solar charge controller

If you are going to harvest solar energy with photovoltaic elements you need a proper charge controller that would take power from panels and convert it to suitable voltage that can be further used for charging or simply powering devices of your choice. The main problems with charge controllers are associated with efficiency. We need that controller power losses were minimal as possible, another point is to take as much power from solar panels as possible. In order to take the most of panel, controller should keep track of maximum power point in element’s I-V curve. This is how modern converters work. This is already third version of solar controller built by deba168. It uses Arduino Nano which controls series of thing including reading voltage and current flowing from solar panel, driving buck converter so that maximum power could be drawn. Then senses voltage on a battery which is being charged. Optionally it controls load MOSFET which drives loads from battery. Arduino is equipped with LCD and WiFi adapter for user interactions. Using MPPT method solar harvesting efficiency can be… Continue reading

Give your plants constant solar light

Ok maybe this isn’t a real solar light as it comes from LED, but the idea is laudable. Idea is pretty simple and not new – harvest solar energy during day and store it in to battery and deliver light to plant during night. In fact there are some difficulties in doing that. Author have used a Luxeon K2 LED that requires over 2,79V, while two NiCad batteries can give around 2V. After some experiments he changed battery to Li-Mh with 3.7V and built an ATTiny15 microcontroller based circuit where LED is controlled by PWM depending on how much energy is left on battery. Battery voltage is measured via MCU ADC channel and depending on voltage level PWM signal is adjusted. This is more fun project to work with as practically LED light cannot replace sunlight. Continue reading