Raspberry Pi has launched the successor to its popular Raspberry Pi Pico board – the Raspberry Pi Pico 2 powered by the RP2350 microcontroller. Since their release, Raspberry Pi has sold more than four million Pico and Pico W. The new board is designed to be faster, more secure, and more energy efficient than its predecessors.
The board features two RISC-V cores which must be exciting for the open source community. The pinout of the new board is backward compatible with the pinout of Raspberry Pi Pico and Raspberry Pi Pico W i.e. it has a total of 40 pins with 20 pins on both sides of the board.
The RP2350 microcontroller is produced using an advanced 40nm process technology which results in low power consumption. This will help to get an extended range when powering the Pico via batteries.
The RP2350 microcontroller
The RP2350 microcontroller is software and hardware compatible with Raspberry Pi Pico 1, the first variant. Here are some of its salient features:
- Dual 150MHz Arm Cortex-M33 cores, or dual 150MHz Hazard3 processors
- 520KB of on-chip SRAM
- Security architecture, built around Arm TrustZone for Cortex-M
- An on-chip switch-mode power supply and low-quiescent-current LDO
- Twelve upgraded PIO state machines
- A new HSTX peripheral for high-speed data transmission
- Support for external QSPI PSRAM
- 2 × I2C controllers
- 2 x UART
- 2 × SPI controllers
- 24 × PWM channels
- 4 x ADC channels
- 1 × USB 1.1 controller
- 12 × PIO state machines
- Operating temperature -20°C to +85°C
- Supported input voltage 1.8–5.5V DC
The new board has also introduced architecture switching –
“RP2350 includes a pair of open-hardware Hazard3 RISC-V cores which can be substituted at boot time for the Cortex-M33 cores. Our boot ROM can even auto-detect the architecture for which a second-stage binary has been built and reboot the chip into the appropriate mode. All features of the chip, apart from a handful of security features, and the double-precision floating-point accelerator, are available in RISC-V mode.”
Raspberry Pi Pico vs Raspberry Pi Pico 2
The RP2350 microcontroller in Pico 2 brings a bunch of improvements over the RP2040 which was used in the first variant.
While Raspberry Pi Pico included 264kB multi-bank high-performance SRAM, the new Pico 2 features 520KB of on-chip SRAM in ten concurrently accessible banks.
RP2040 provided only a single 7×7mm, QFN56 package option. The company states that the latest chip will be offered in “QFN60 package (RP2350A) with 30 GPIOs, or a 10×10mm, QFN80 package (RP2350B) with 48 GPIOs; and variants of each with 2MB of stacked-in-package QSPI flash (RP2354A and RP2354B).” This allows developers to be flexible with their designs when building their own development boards and projects.
The new chip has also leveled up in terms of security. RP2350 is built around Arm TrustZone for Cortex-M, which includes features such as:
- Signed boot support
- 8KB of on-chip antifuse one-time-programmable (OTP) memory
- Hardware SHA-256 acceleration
- A hardware true random number generator (TRNG)
Signed boot support is a security feature that guards against malicious code and unauthorized modifications to the system by guaranteeing that only trusted and authenticated firmware or software is loaded at boot. One-time programmable (OTP) memory is a type of memory that can be written to only once and then permanently stores the data.
SHA-256 acceleration is designed to speed up the computation of the SHA-256 cryptographic hash function, making data encryption and verification processes faster and more efficient. The TRNG helps in cryptographic key generation.
These security features will help to protect your code in case you want to make a commercial product with the RP2350.
Wrapping Up
Wi-Fi and Bluetooth are not available on Pico 2. The lack of a USB Type-C port might be disappointing for some. A new variant with these features will be welcomed, just like they did with the Pico W.
According to the company’s blog post, Pico 2 W will also be available later this year – “Before the end of the year, we expect to ship a wireless-enabled Pico 2 W, using the same Infineon 43439 modem as Pico W, and versions of both Pico 2 and Pico 2 W with pre-installed 0.1-inch headers.”
Pico 2 can be programmed using C/C++ and Python. Hopefully, MicroPython and CircuitPython support will arrive soon.
The company has assured that Raspberry Pi Pico 2 will remain in production until at least January 2040. The product is now on sale for $5. You can learn more about the RP2350 microcontroller by reading its datasheet or by visiting its official documentation.
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