While searching Tindie for a new project, I found a new Raspberry Pi RP2350B-based development board called “Bells&Whistles,” which is interesting because it also features an onboard RP2040-based debugger running Picoprobe firmware, removing the need for a separate debug probe.
Other than that, it has an HDMI output, a MicroSD card slot for storage, an optional 8 MB of PSRAM, and since it uses the Raspberry Pi RP2350B variant, it supports up to 46 GPIO pins. The board also features two USB Type-C ports, one for the RP2350B and the other for the RP2040 debugger, and is especially useful for clutter-free rapid prototyping and development workflows.
RP2350B bells&whistles board specifications:
- SoC – Raspberry Pi RP2350B
- CPU
- Dual-core Arm Cortex-M33 @ 150 MHz with Arm TrustZone
- Dual-core RISC-V Hazard3 @ 150 MHz
- Only two cores can be used at any given time
- Memory – 520 KB on-chip SRAM
- Package – QFN-80
- CPU
- Memory – Optional 8 MB PSRAM
- Storage
- 4 MB on-board SPI flash
- MicroSD card slot (wired to GPIO20-GPIO23)
- Video Output – HDMI connector for DVI video output
- USB – 2x USB Type-C ports (one “USB RPI” for the main RP2350B, one “USB DBG” for the debugger)
- Debugging – On-board Raspberry Pi RP2040 microcontroller running Picoprobe software
- Expansion – 2x 30-pin headers exposing 46x GPIOs, 5V, 3.3V, and GND
- Misc
- Reset (RST) and Boot buttons for both the main MCU and the debugger
- 1x User LED (GPIO46)
- UART routed internally to the debugger (GPIO0, GPIO1)
- Power
- 5V from USB-C
- VBUS and 3.3V(out) pins
- Dimensions – 87 x 26.5 mm
On the software side, the board is designed to work with existing projects. The HDMI connector uses the same GPIO pins (GPIO12 to GPIO19) as the Adafruit DVI Sock (which is based on Luke Wren’s PicoDVI project), so it works with software based on the PicoDVI library. The onboard debugger works like a standard Raspberry Pi debug probe, so you can program the board and use UART monitoring without needing extra hardware.
The RP2350B Bells&Whistles board is also open-source hardware. The developer, riktw, has published the KiCad schematics, PCB layout files, and a PDF schematic under an MIT license on GitHub.
We have previously written about various types of RP2350-based development boards, such as the Waveshare RP2350B-Plus-W, the picoZ80 board, the pico-ice FPGA development board, and others, but none of them include an onboard RP2040-based debugger.
The board is currently sold as a fully populated and tested PCBA (headers not included) on Tindie for $29.95. There is also an optional add-on available for an extra PSRAM chip, which comes factory-soldered to the board. Shipping from the Netherlands starts at $7.00 for standard ground shipping.
Debashis Das is a technical content writer and embedded engineer with over five years of experience in the industry. With expertise in Embedded C, PCB Design, and SEO optimization, he effectively blends difficult technical topics with clear communication
Support CNX Software! Donate via cryptocurrencies, become a Patron on Patreon, or purchase goods on Amazon or Aliexpress. We also use affiliate links in articles to earn commissions if you make a purchase after clicking on those links.
