In this Getting Started tutorial, we will learn about the Raspberry Pi Pico, a brand new exciting Microcontroller board based on RP2040 Microcontroller from the Raspberry Pi Foundation. The Raspberry Pi Pico is a low-cost Arm-based microcontroller that we can program using C/C++ and MicroPython.
Over the years Raspberry Pi boards have become a must tool for students, hobbyists,s or Industrialists. But when it comes to cost, the Raspberry Pi Board is overtaken by Arduino, ESP32, STM32, or other AVR, ARM, and PIC Microcontrollers. The Raspberry Pi computer costs around 35-40$ whereas the other microcontrollers barely cost 2-5$ only. This is the reason why Raspberry Pi Foundation released their low-cost powerful competitive Raspberry Pi Pico Board with RP2040, a Dual Core ARM Cortex-M0+ Microcontroller.
The tutorial covers the RP2040 Microcontroller, its features & specifications. We will also learn about the Raspberry Pi Pico Board, its layout, and specifications. The detailed guide of Raspberry Pi Pico Pins like ADC pins, I2C Pins, SPI Pins, UART, etc can help you to interface any sensors or module with this powerful board.
Since it’s a Raspberry Pi Pico getting started tutorial, so we will only program the device using Micropython. For that, you can either use Thonny IDE or you can also go with uPyCraft IDE. In some other tutorials, we will learn how to program Raspberry Pi Pico with C/C++. Even the Arduino IDE will support Raspberry Pie Pico in the future as it is in the development phase now. We will go through the basic Raspberry Pi Pico LED Blink Code & check the board functionality.
What is the RP2040 Microcontroller?
Earlier all the Raspberry Pi boards like Raspberry Pi 3 or 4 or Raspberry Pi Zero featured Broadcom Processors like BCM2835, BCM2836, BCM2711, etc. The RP2040 chip was announced on 21st January 2021 and is the first processor designed by the Raspberry Pi Foundation.
The RP2040 is a 32-bit dual ARM Cortex-M0+ microcontroller integrated circuit released simultaneously as part of the Raspberry Pi Pico board. The processor is a low-cost microcontroller and costs around US$4. The chip is 40nm silicon in a 7×7 mm QFN-56 package.
The RP2040 contains two ARM Cortex-M0+ cores clocked at 133 MHz together with 264 KB of RAM. The Program memory is external and supports up to 16 MB. The device has everything you expect from a modern microcontroller like UARTS, SPI, and I2C ports, and there are timers, PWM, DMA, and a 12-bit analog-to-digital converter (ADC).
Meaning of RP2040
The name RP2040 has an exciting meaning explained below.
1. RP means: Raspberry Pi
2. Number 2 means: Processor Cores as a dual-core microcontroller. So, the value is 2.
3. Number 0 means: Type of Processor Core as it is ARM Cortex-M0+. So, the value is 0.
4. Number 4 means: Represents On-chip RAM. RP2040 has 264 KB of RAM. The formula to get 4 values is floor (log2 (ram / 16k)). So, the value is 4.
5. Number 0 means: Represents On-chip Flash. As there is no on-chip flash, the value is 0.
RP2040 Key features:
1. 133MHz dual ARM Cortex-M0+ cores
2. 264kB SRAM in six independent banks
3. Support for up to 16MB of off-chip Flash memory via a dedicated QSPI bus
4. DMA controller
5. Fully-connected AHB crossbar
6. Interpolator and integer divider peripherals
7. On-chip programmable LDO(Low-dropout_regulator) to generate core voltage
8. 2 on-chip PLLs to generate USB and core clocks
9. 30 GPIO pins, 4 of which can be used as analog inputs
Introduction to Raspberry Pi Pico
The Raspberry Pi Pico is the first microcontroller board based on the RP2040. It looks a lot like other microcontroller boards with the MCU in the center, a micro-USB connector on one end, and a row of contacts along each side. A 3-pin debug connector is available at the other end of the board.
The Raspberry Pi Pico measures 51 by 21 mm, which is the exact same size as an ESP32 Pico Kit & slightly larger than an Arduino Nano or Micro. The Pico comes with 2 MB of QSPI Flash memory and 25 of the 30 GPIO pins of the RP2040 have been brought out on the extension connectors. The board is breadboard friendly and fits perfectly on a breadboard.
Features of Raspberry Pi Pico
Following are the features of the Raspberry Pi Pico Board.
1. Based on RP2040 Microcontroller
2. 2 MB of SPI Flash Memory
3. Type B Micro-USB port for power & programming
4. 40 DIP style IO Pins
5. 3-pin ARM Serial Wire Debug (SWD) interface
6. 12 MHz Crystal oscillator
7. Boot Selection Button
8. Programmable LED connected to GPIO 25
9. 3.3V Fixed Output Buck-Boost SMPS Converter
Raspberry Pi Pico Pinout
There are 40 pins on the Raspberry Pi Pico. Out of those 40 pins, 26 pins are Input-Output (IO Pins). All those 14 pins are analog, digital, and other Serial Pins. There are 14 power and system-related pins. The remaining 3 more pins are used for SWD Debugging.
There are two I2C peripherals available, I2C0 and I2C1. Similarly, there are two SPI peripherals, SPI0 and SPI1The number of UART Pins is also two, UART0 and UART1. You can assign any of these to the pins on which they are available.
Before you start using Raspberry Pi Pico, you have to solder 40-pin male headers, 20 on each side of the board.
Programming Raspberry Pi Pico
The Pi Pico can be programmed using C/C++ or Python, among other languages. Pico is adaptable to a vast range of applications and skill levels, and getting started is as easy as dragging and dropping a file. If you are working with C, then it is recommended to use a Linux-based system like a Raspberry Pi Computer as it is easy to download the SDK and write C Programs in Linux.
But I will recommend using MicroPython to program the Raspberry Pi Pico Board. MicroPython is a Python Language Interpreter that is developed for Microcontrollers and embedded systems. The Syntax for MicroPython is very similar to Python. So, if you worked with Python, then working with MicroPython will be very easy.
To program the Raspberry Pi Pico using Micropython, you can either use:
1. Thonny IDE
2. uPyCraft IDE
But before getting started with Raspberry Pi Pico, you have to install MicroPython on Raspberry Pi Pico Board.
Installing MicroPython on Raspberry Pi Pico
Push and hold the BOOTSEL button on the Pico, & then immediately connect the Pico Board to your computer using a micro USB cable. Release BOOTSEL once the drive RPI-RP2 appears on your computer.
Open the RPI-RP2 drive that appears in the Drives tab.
Visit the Raspberry Pi Pico Official Documentation page from here: Raspberry Pi Documentation.
Download the MicroPython UF2 file from the MicroPython tab.
Drag and drop the UF2 file onto the RPI-RP2 drive. The Raspberry Pi Pico will reboot and will now run MicroPython.
Tutorial Source : https://how2electronics.com/raspberry-pi-pico-getting-started-tutorial-with-micropython/