Adafruit’s Fruit Jam, first teased as a work-in-progress in early 2025, is now shipping at $39: a 3.4×2.1-inch single-board computer built not around a Linux-capable application processor but around Raspberry Pi’s RP2350B microcontroller — two Cortex-M33 cores at up to 150MHz, augmented with 8MB of PSRAM, 16MB of flash, and 520KB of on-chip SRAM. Around that core, Adafruit has assembled everything a standalone machine needs: DVI-D video output up to 1280×720, two USB-A ports for a keyboard and mouse or gamepad, WiFi 6 and Bluetooth 5 via an onboard ESP32-C6, a microSD slot, a 1-watt speaker, three tactile buttons, an IR receiver, and a 16-pin GPIO header.
Watch: Adafruit Fruit Jam — Mini RP2350 Computer (YouTube)
A computer, not a dev board
The distinction that makes the Fruit Jam interesting is the completeness. Microcontroller boards normally assume a host computer on the other end of a USB cable; Linux SBCs like a Raspberry Pi 5 give you a desktop but bring an operating system, SD-card images, and boot times along. The Fruit Jam occupies the gap: plug in a monitor and keyboard and it’s a self-contained machine that boots instantly into whatever it’s programmed to be — the community has already run everything up to a classic Macintosh emulator on it. For anyone who grew up on 8-bit home computers, the shape of the thing is familiar on purpose.
Why instant-boot matters for installations
For creative-hardware builders, the killer property is the boot model. An installation built on a Linux SBC has to manage an OS: safe shutdowns, filesystem corruption after power cuts, seconds-to-minutes of boot time when a gallery flips the breakers each morning. A microcontroller-architecture machine with video, audio, USB input, and WiFi eliminates that entire category of failure — power on, running; power off, nothing to corrupt. With CircuitPython as the native workflow, the iteration loop is also as simple as editing a file, putting it in the same accessibility tier as the OpenMV AE3 covered here previously: real capability without an embedded toolchain.
The RP2350B detail
The board also showcases what distinguishes the RP2350B variant specifically — more GPIO than the standard RP2350, which is how the design affords DVI, dual USB ports, and the full peripheral set simultaneously. Between this, the Raspberry Pi 500+ keyboard computer, and the growing catalog of RP2350-based instruments and cyberdecks, the pattern is clear: the microcontroller-as-computer category that the original Pico accidentally created is now getting deliberate, polished hardware.
Related Reading
- Adafruit Fruit Jam — Mini RP2350 Computer — Adafruit product page
- Adafruit Unveils a Work-in-Progress Raspberry Pi RP2350B Single-Board Computer, the “Fruit Jam” — Hackster.io
- Fruit Jam Mini Computer Features RP2350B, ESP32-C6 WiFi, and DVI Video — LinuxGizmos
- Overview — Adafruit Fruit Jam — Adafruit Learning System