Troubleshooting

One of the first problems many users run into is also one of the most annoying: the Arduino, ESP32, ESP8266, RP2040 or other microcontroller board is plugged into USB, but the computer does not show a serial port. The board may light up. The power LED may be on. But the Arduino IDE does not […]

Arduino, ESP32, sensors, displays and electronic modules make modern electronics much easier than it used to be. A beginner can connect a microcontroller, upload a sketch and make something blink, measure, move or display text within minutes. But “easier” does not mean “automatic.” Electronics still follows electrical rules. A module will not work correctly if

One of the most common Arduino problems is a sketch that compiles correctly but does not upload. The Arduino IDE may show an error from avrdude, the progress bar may stop, or the board may simply fail to respond. This is especially common with classic Arduino Uno, Nano, Mega and compatible clone boards. The problem

An ESP32 that keeps rebooting after uploading a sketch can be very confusing. The upload may finish successfully, but the board immediately restarts again and again. The serial monitor may show repeated boot messages, watchdog errors, brownout warnings, stack traces, or the same setup message printed over and over. This problem is different from an

I2C is popular because many sensors, displays, real-time clocks, ADCs, DACs and I/O expanders can share the same two signal wires: SDA and SCL. This makes wiring much cleaner than using a separate set of pins for every module. But I2C has one important rule: each device on the same bus must have its own

I2C is one of the most useful communication interfaces for Arduino, ESP32, ESP8266, RP2040, Raspberry Pi Pico and CANABLOX projects. It allows many sensors, displays, real-time clocks, ADCs, DACs and I/O expanders to share only two signal wires: SDA and SCL. But I2C has one important electrical detail that causes many real-world problems: the bus

One of the most common ESP32 problems is an upload error that says something like “Timed out waiting for packet header”, “Failed to connect to ESP32”, or “No serial data received.” This can be very frustrating because the board may appear to be connected correctly, the USB port may show up in the Arduino IDE,

A very common troubleshooting situation is this: an I2C display, sensor, RTC, ADC or I/O expander works perfectly with an Arduino Uno, but the same module does not work with an ESP32. The I2C scanner may find nothing, the display may stay blank, or the sensor library may report that the device is missing. This

An I2C scanner is one of the most useful troubleshooting tools for Arduino, ESP32, ESP8266, RP2040 and similar microcontroller projects. It sends test messages to all possible I2C addresses and reports which devices answer. When everything is wired correctly, an I2C scanner usually prints one or more addresses such as 0x3C, 0x27, 0x68 or 0x48.

Analog sensors are often used with Arduino, ESP32, ESP8266, RP2040 and other microcontroller boards to measure light, temperature, voltage, position, pressure, moisture or sound level. The idea seems simple: connect the sensor output to an analog input and read a number. In real projects, analog readings are often more confusing. The value may jump around,