The Raspberry Pi RP2040 and Espressif ESP32 are two of the most popular microcontroller units (MCUs) used by hobbyists and engineers alike. Both offer compelling capabilities at affordable prices, but they have some important differences that users should consider when selecting a microcontroller for their next project.
Introducing the RP2040 and ESP32
The RP2040 was introduced in early 2021 by Raspberry Pi as the microcontroller powering their Pico board. It features a dual-core Arm Cortex M0+ processor running at up to 133 MHz, 264KB of on-chip SRAM, and support for up to 16MB of off-chip Flash memory. The RP2040 is fabricated with a 40nm process and integrates much of the functionality needed for an embedded application, including timers, ADC, DAC, SPI, and I2C.
The ESP32 from Espressif has been available since 2016 and employs a dual-core Xtensa LX6 microprocessor with clock speeds up to 240 MHz. It has 520KB of SRAM and supports external Flash up to 16MB. The ESP32 is fabricated with a 40nm process and includes an impressive amount of peripherals such as capacitive touch, Hall sensors, SD card interface, Ethernet, high-speed SPI, I2S and I2C.
Performance and Benchmarks
In terms of raw processing power, the ESP32 has a clear advantage with its faster 240 MHz clock speed compared to 133 MHz on the RP2040. However, both are capable 32-bit MCUs with more than enough horsepower for most embedded and Internet of Things applications. The RP2040 uses a simpler but more power efficient processor design based on Arm Cortex M0+, while the ESP32 employs the more advanced Xtensa cores.
For memory, the 520KB SRAM on the ESP32 dwarfs the 264KB available on the RP2040. Again, both have enough memory for typical tasks but the extra capacity on the ESP32 provides more flexibility for complex data processing algorithms or buffering data streams.
Various benchmarks have shown the ESP32 performing 1.5x to 2x faster than the RP2040 on typical tasks. However, the RP2040 consumes less power and can operate efficiently down to 1.8V while the ESP32 needs 3.3V. So for low power applications, especially when running from batteries or energy harvesting sources, the RP2040 has the advantage.
Peripheral Features and I/O Options
A key difference between these two MCUs is the peripheral features integrated on chip. The RP2040 has a decent set of peripherals including dual SPI controllers, two I2C controllers, and multiple PWM and ADC channels. However, the ESP32 supports a much broader range thanks to its purpose-built design for wireless networking and Internet of Things connectivity.
For example, the ESP32 includes an Ethernet MAC, high speed SPI Master/Slave, SD card interface, capacitive touch sensing, Hall effect sensors, and support for external memories like SRAM and Flash. It also can interface with cameras, LCDs, and other advanced peripherals.
In terms of connectivity, both microcontrollers have dual SPI, dual I2C, UART, PWM and ADC capabilities. However the ESP32 sets itself apart with built-in support for WiFi, Bluetooth Classic/BLE, and TCP/IP networking. These make it easier to add wireless capabilities to projects and connect to the Internet.
For external I/O expansion, each board uses different standards. The RP2040 supports high speed I/O via its two PIO state machines. The ESP32 utilizes SPI, I2S, SD cards, and other ports. There are expansion boards available for both MCUs that add many additional I/O options.
Power Consumption and Battery Operation
When it comes to power consumption, the RP2040 is more efficient than the ESP32. At 3.3V supply voltage, the RP2040 draws around 0.2 mA per MHz of clock speed. So at 133 MHz it can operate at approximately 27 mA. The ESP32 at 240 MHz consumes around 240 mA in active mode. However the ESP32 can run in power save mode at down to 2.5 mA.
This means the RP2040 is better suited for low power battery applications. It can operate for a couple years on a coin cell battery. The ESP32 is not optimized for ultra low power and will require larger batteries or super capacitors to function for long periods in deep sleep mode.
Both chips can operate at lower voltages like 2.5V or 1.8V but with reduced performance. The minimum operating voltage is 1.8V on the RP2040 and 2.5V on the ESP32.
Development Environments
Given its origins with Raspberry Pi, the RP2040 is well supported in Raspberry Pi’s own C/C++ SDK and Python runtime. There is an extension for Visual Studio Code to program the chip in C/C++ and MicroPython. Many Arduino style examples are available which provide an easy starting point.
For the ESP32, Espressif provides several development frameworks. The ESP-IDF supports programming in C and C++. There are also Arduino cores so the chip can be programmed through the Arduino IDE. Many other environments like MicroPython and Zerynth also support the ESP32.
Overall, both MCUs can be programmed in C and MicroPython. The RP2040 has better out-of-the-box support with Raspberry Pi’s own tools while Espressif’s ESP32 is widely supported across many vendor agnostic development environments.
Community and Ecosystem
The popularity of Raspberry Pi products has established an enormous community around their technologies, including the RP2040. There are active forums and detailed documentation provided by Raspberry Pi to assist developers. The chip’s use in the low cost Pico board makes it very beginner friendly.
Meanwhile, Espressif has cultivated a similarly large following around the ESP32 over the past six years. There is no shortage of technical guidance and PROJECT examples available for the chip. Its wireless capabilities and affordability have made it popular with hobbyists and professionals alike.
In terms of hardware support, both MCUs have spawned an ecosystem of boards and modules for easy integration. The RP2040 is designed specifically for the Raspberry Pi Pico but third parties provide other form factors. The ESP32 is available in standalone modules as well as development boards from Espressif and others.
So users of either microcontroller benefit from engaging technical communities and plenty of hardware options for building real-world applications.
Price and Availability
The affordability of these microcontrollers makes them very popular choices for DIY electronics and professional products alike. The RP2040 retails for around $1 when purchased as part of the Raspberry Pi Pico board. Espressif sells the ESP32 starting at around $2.50 for standalone modules in volume orders.
Both MCUs are readily available through normal distribution channels. The supply of the RP2040 has ramped up significantly after initial shortages in early 2021. There are also many clones, official dev boards and modules that incorporate the ESP32 widely available.
For most projects, the price difference between the two microcontrollers is not significant. Both deliver excellent value while providing high performance and capability for the cost.
Conclusion
The Raspberry Pi RP2040 and Espressif ESP32 represent two of the most versatile chip options for embedded and IoT applications today. They both offer compelling capabilities at extremely affordable price points.
For projects requiring wireless connectivity or complex real-time data processing, the ESP32 is likely the better choice. Its mix of memory, peripherals and networking features make it hard to beat. But for low power battery powered devices, the power efficiency of the RP2040 makes it a compelling option.
Both microcontrollers benefit from generous community support and documentation. And there are great development tools available on both sides. While their strengths differ, you can count on the RP2040 and ESP32 to handle most embedded application needs with ease.
