Raspberry Pi Pico Pinout Explained: Fun and Easy Guide for Students
Welcome back, young makers! Today, we’ll explore the exciting world of the Raspberry Pi Pico pinout. Understanding the pinout is crucial for connecting and using various components with your Pico. Let’s dive in!
Understanding the Pinout
The Raspberry Pi Pico has several pins, each identified with unique letters and numbers. Here’s what each type of pin does:
| Pin Label | Description |
|---|---|
| GND | Power supply ground (digital ground) |
| AGND | Power supply ground (analogue ground) |
| 3V3 | +3.3 V power supply (output) |
| GP0 – GP22 | Digital GPIO (General Purpose Input/Output) |
| GP26_A0 – GP28_A2 | Analogue inputs |
| ADC_VREF | ADC (Analogue to Digital Converter) reference voltage |
| TP1 – TP6 | Test points |
| SWDIO, GND, SWCLK | Debug interface |
| RUN | Default RUN pin. Connect LOW to reset the RP2040. |
| 3V3_EN | Enables the +3.3V power supply. +3.3 V can be disabled by connecting this pin LOW. |
| VSYS | System input voltage (1.8 V to 5.5 V) used by the onboard SMPS to generate +3.3 V supply for the board. |
| VBUS | Micro-USB input voltage (+5 V) |
Special GPIO Pins
Some of the GPIO pins on the Pico are used for specific internal functions:
| Pin Label | Function |
|---|---|
| GP29 (input) | Used in ADC mode (ADC3) to measure VSYS/3 |
| GP25 (output) | Connected to the on-board user LED |
| GP24 (input) | VBUS sense – HIGH if VBUS is present, else LOW |
| GP23 (output) | Controls the on-board SMPS Power Save pin |
Let’s Dive Deeper!
To make it even clearer, here’s a detailed breakdown of some key pin types and their uses:
- GPIO Pins (GP0 – GP22): These pins are like versatile workers on the Pico. They can be used for both input (like reading data from a sensor) and output (like lighting up an LED).
- Analogue Inputs (GP26_A0 – GP28_A2): These special pins can read varying voltage levels from devices like temperature sensors. Instead of just ON or OFF, they understand different levels, which is great for more precise readings.
- Power Pins (3V3, VSYS, VBUS): These are the lifelines of the Pico, providing the necessary power to the board and any connected components. Remember, always be careful with voltage levels to avoid damaging your Pico.
- Debug Pins (SWDIO, SWCLK): These are used by developers to troubleshoot and debug their programs. Think of them as the secret keys to understanding what’s going on inside the Pico.
- Test Points (TP1 – TP6): These are used for testing purposes. They help in making sure everything is working perfectly on the board.
Important Notes for GPIO Pins
- Direct Connection: The GPIO pins are directly connected from the microcontroller chip to the GPIO connector.
- Dual Functionality: GPIO numbers 26-28 can be used either as digital GPIO or as ADC inputs.
- Voltage Limit: ADC inputs GPIO26-29 have reverse-biased diodes to 3V, so the input voltage must not exceed 3.3V + 300 mV.
- Power Consideration: If the RP2040 is not powered, applying voltages to GPIO26-29 pins may leak through the diode to the power supply. However, this is not a problem with the other GPIO pins.
Visual Guide
Here’s a handy visual guide to help you identify the pins on your Raspberry Pi Pico:
Figure 1.2: Back view of the Pico hardware module.
Fun Facts
- GPIO Pins: These pins can be used to connect various sensors, LEDs, and other components to your Pico.
- Analogue Inputs: Perfect for connecting devices like temperature sensors that provide analogue signals.
- Debug Interface: Essential for developers to debug their programs.
Practical Tips
- Always Check the Voltage: The Pico’s GPIO pins are designed to work with 3.3V. If you’re using a component that operates at 5V, make sure to use a logic level converter to avoid damaging your Pico.
- Double-Check Connections: Before powering up your Pico, double-check all connections to make sure everything is connected properly. This can prevent short circuits and other issues.
We hope this guide helps you understand the pinout of your Raspberry Pi Pico. Stay tuned for more exciting projects and tutorials! 🚀
