LED Limitations

247

02:01:32

Here are some examples of dev board voltages and their limitations on the voltage/current that GPIO pins can sink/source.

The first is Renesas 32-bit MCU on the Arduino R4, which states a recommended maximum of 8 mA per pin and outputs 5V on pins.

The second is the ATMEGA32U (Uno R3, classic Nano, etc) which states a recommended maximum of 20 mA per pin (some sources say as high as 40 is fine) and it outputs 5V per pin.

The third is an example of 3.3V per the Raspberry Pi models with a suggested maximum of 16 mA per pin.

The fourth is an ESP32 example that outputs 3.3V per pin and recommends 8 or below mA.

Each example has a standard value resistor in place that should work fine with a green LED (2v, 20mA) on each setup.

There are sources that suggest higher values such as 470 instead of 430, 300 or 330 instead of 200 for 5V to allow for a wider margin-of-error and spikes.

published 8 months ago

eekee

8 months ago

You can get low-current LEDs, or you could in the 90s. 1 or 2 mA was typical.

add comment in editor

EveryCircuit is an easy to use, highly interactive circuit simulator and schematic capture tool. Real-time circuit simulation, interactivity, and dynamic visualization make it a must have application for professionals and academia. EveryCircuit user community has collaboratively created the largest searchable library of circuit designs. EveryCircuit app runs online in popular browsers and on mobile phones and tablets, enabling you to capture design ideas and learn electronics on the go.