Adafruit Shows Off Upcoming CAN Bus, USB Host RP2040-Powered Development Boards
RP2040's second core and PIO press-ganged into bit-banged USB duties, while a single-chip CAN bus controller extends its capabilities.
Adafruit has teased two new Raspberry Pi RP2040-based Feather-format development boards, each with a particular focus: one aiming to provide a low-cost entry point for CAN bus development and the other offering a Programmable Input/Output (PIO)-driven USB Host function.
"You're probably saying 'hey wait, the RP2040 doesn’t have a secondary USB port! so what’s that USB A port doing on this fancy new Feather?' Well," explains Adafruit's Phillip Torrone of one of the two new boards unveiled by the company this week, "we do have a bit-banged 'full speed' USB host implementation available in TinyUSB. Sure, it uses all the PIO slots and the second core but for some projects — say, a data-logger that writes to a USB key, or an HID re-mapper — this board could do a fair job at it!"
The Feather-format board is, as Torrone explains, built around the Raspberry Pi RP2040 — and makes heavy use of its features. One of the two Cortex-M0+ cores works alongside the clever Programmable Input/Output (PIO) blocks to drive a full-size USB Type-A port at one end of the board, acting as a USB Host for external hardware from input devices to storage. A Texas Instruments TPS61023 has been added in order to provide a sustained 500mA of current and handle a 1A peak, Torrone explains, which should be good for most USB 2.0-compliant hardware.
The YACBB, meanwhile, uses the same RP2040 microcontroller but with a focus on connecting to CAN bus hardware rather than USB peripherals. Based on Microchip's MCP25625, a single-chip CAN bus controller, the board provides CAN bus connectivity along with a shared SPI port. "We’ll still need a 5V booster," Torrone notes, "shown in the top right area."
Thus far, Adafruit has only shown off renders of the new boards — with no word yet on pricing and availability.