Yes, it’s possible to power an Arduino directly from a solar Panel, but not reliably without extra components. A solar Panel’s voltage and current fluctuate with sunlight, which can cause the Arduino to reset or even get damaged. To make it work safely, you’ll need at least a regulator (buck or buck-boost) to keep the voltage stable, a blocking diode to prevent reverse current at night, and some capacitors or a supercapacitor to smooth out short drops in power. Without a battery, the project may still cut off under clouds or low light, so if continuous operation is required, even a small buffer battery or supercap is highly recommended.

Is it possible to power an Arduino project directly from a solar Panel without using a battery? I’m concerned about voltage fluctuations and whether the Arduino can handle them, or if additional components are required to make it work safely.

@neeraj-dev What do you mean by, "I’d like to have a WAll-mounted switch that can wirelessly communicate with an Arduino-based controller connected to the lights". Why do you need a WAll-mounted switch to make this project wireless?

The main reason Teensy is preferred for DIY keyboards is its native USB support. Unlike most Arduino boards (like Uno, Nano, Pro Mini) that use a separate USB-to-serial chip, Teensy’s microcontrollers handle USB directly. This allows them to appear as a true USB HID device (keyboard, mouse, MIDI, etc.) without extra work. On top of that, Teensy boards generally offer more flash, RAM, and faster processors, which makes them well-suited for complex keyboard firmware like QMK or TMK that require Custom layouts, macros, and lighting effects. The Arduino Uno/Nano can’t natively emulate a keyboard without workarounds, while Teensy supports it out of the box.

I’ve seen many DIY keyboard projects where people use a Teensy microcontroller rather than popular Arduino boards like the Uno, Nano, or Pro Mini. What makes the Teensy a better choice for keyboards? Is it related to USB support, performance, or something else.

Hi everyone! I'm an electrical engineering student who is new to home automation projects but has started working on one and needs some advice. I WAnt to create a system where I can control the lights in my house wirelessly. Specifically, I’d like to have a WAll-mounted switch that can wirelessly communicate with an Arduino-based controller connected to the lights. The goal is to replace the traditional wired switches with wireless ones that can send on/off commands to the Arduino, which will then control a relay to turn the lights on or off. I've researc ...

Nicely explained! Do you know if the ESP32-C3’s USB Serial/JTAG can be extended to support HID with Custom firmware, or is it strictly limited to debugging and flashing?

I need a board with native USB support for HID or Custom USB projects, and I’m trying to decide between the ESP32-C3 and ESP32-S3. Do both support native USB, and which one is more reliable for this purpose?

For a portable IoT device, Li-ion is generally the better choice because of its higher energy density and longer lifespan. It’ll give you more runtime per charge and is easier to manage in terms of charging circuits and protection. That said, Li-Po can work for IoT devices, but it’s usually overkill unless you have specific design constraints—like needing a really thin form factor or a Custom shape that standard Li-ion cells don’t fit. One area where Li-Po might make sense is if your device has occasional power spikes, since Li-Po batteries can handle higher discharge rates.

I totally agree with Jeff. Building a Custom PCB including a microcontroller chip for a personal project such as automating your room is one thing and you may even save a few bucks than buying the dev board separately. But when you WAnt to sell this product to consumers that's a whole different story. You can't possibly think that assembling some parts on 10 PCBs and saving money is anything like doing business. It takes a lot to create a profitable business out of this.

A capacitor is called linear because the relationship between the voltage across it and the current flowing through it is linear. The exponential curve you're seeing is its behavior over time, which is different. Here’s the breakdown: What "Linear" actually means here In circuit theory, a component is linear if it follows the rule of superposition and scaling.1 In simple terms: if you double the cause, you double the effect. For a capacitor, the relationship is defined by the equation 2I=CdtdV​.3 This means the current (4I) is directly proportional to the rate of change of voltage (5dV/dt).6 So, if you double the current going into the cap, its voltage changes twice as fast. If you halve the current, its voltage changes half as fast. That direct, proportional relationship is what makes it a linear component. So why the exponential curve? That famous exponential curve shows the capacitor's voltage versus time when it's part of a circuit with a resistor (an RC circuit). It's not a direct graph of voltage vs. current. Think about what happens when you charge it: At the start, the capacitor is empty, so a large current flows in. As it charges, voltage builds up across it. This built-up voltage opposes the source, which reduces the voltage across the resistor, and therefore reduces the current flowing into the cap. So, the charging slows down as it gets fuller. This process of "charging slower and slower as it fills up" is what creates that exponential curve. The capacitor itself is still behaving linearly at any given instant, but the behavior of the whole circuit over time is exponential. So: Component's V-I relationship: Linear. (The physics of the cap itself). Circuit's V-T response: Exponential. (The behavior you see over time in an RC circuit). Hope that clears it up!

... size. The same can be said for all Arduino units. The UNO, NANO, MEGA etc are perfect as training aids and for those without the ability to produce pcbs but final products can be greatly reduced in size by using the ATMEL uController in Custom pubs. I WAs an advocate for the PIC chip series and indeed I still am but since discovering Arduino I have become a fan. As yet in Arduino I am still a beginner but I have 50 years experience in designing electronics. Cheers Jeff Monegal