Adafruit Launches New CAN Bus Boards and a Neat Feather RP2040 with HDMI-Compatible Video Port
If you're working with automotive or robotics the CAN bus boards could be for you, while the new Feather offers low-cost digital video.
Update (04/11/23): Adafruit's Feather RP2040 with DVI, which uses an HDMI-style connector for broad compatibility with common monitors and TVs, is now available to buy, priced at $14.95 before volume discounts.
Based on the PicoDVI project, the Feather RP2040 with DVI offers up to a 400×240 resolution with 16-bit color from either the Arduino IDE or the Raspberry Pi Pico software development kit (SDK) — but, at the time of writing, was not yet supported in CircuitPython.
The board is available to order now on the Adafruit store.
Original article continues below.
Adafruit has launched a trio of new boards, including two aimed at those working on automotive or other CAN bus projects and one which gives you an easy way to hook a Raspberry Pi RP2040 microcontroller up to an HDMI display.
"CAN Bus is a small-scale networking standard, originally designed for cars and, yes, busses, but is now used for many robotics or sensor networks that need better range and addressing than I2C, and don't have the pins or computational ability to talk on Ethernet," Adafruit writes of its latest CAN-based devices. "CAN is two-wire differential, which means it's good for long distances and noisy environments."
The first of Adafruit's new CAN bus devices is the CAN Bus FeatherWing, based on the Microchip MCP2515 CAN controller — chosen for its broad compatibility, with stable libraries for both Arduio and MicroPython/CircuitPython projects. Compatible with any Feather board, including third-party boards which correctly implement the Feather pinout, the FeatherWing attaches to the board and offers full CAN bus support — including the use of a 5V charge-pump voltage generator to properly power the NXP TJA1051/3 transceiver and options for 3.5mm terminal block or an edge-launch DE-9 connector.
If you've got a board which already boasts native CAN support, Adafruit's second new board will be of interest. Dubbed the CAN PAL, the tiny board packs the same NXP TJA1051/T3 transceiver and 5V charge-pump voltage generator as the CAN BUS FeatherWing — but lacks a CAN controller of its own. Instead, it's designed to be used with microcontrollers offering an integrated controller but no on-board transceiver — like the Espressif ESP32 family, the Microchip AT SAME51, STMicro STM32F405, or Teensy 4.
Adafruit's final new board, which at the time of writing was still listed as "coming soon," is the Adafruit Feather RP2040 with DVI Output Port. Mashing together the company's existing Feather RP2040 and DVI Breakout Board designs, the new Feather offers a single-board solution to getting a Raspberry Pi RP2040 controller talking to HDMI displays — using the sneaky workaround of sending DVI signals over an HDMI cable to avoid having to pay a fee to license the HDMI standard.
"In Arduino, which is what we recommend, we use our fork of [Luke Wren's] PicoDVI to create an internal framebuffer of 320×240 or 400×240 16-bit pixels that is then continuously blitted out as pixel-doubled 640×480 or 800×480 digital video. Note that the DVI video generation uses one full core, both PIOs [Programmable Input/Output blocks], and 150k[B] (320×240) or 190k (400×240) of SRAM. It's kinda maxed out so be aware of the remaining resource limitations."
The Adafruit CAN Bus FeatherWing is now available to order at $12.50; the CAN Pal is priced at $3.95, though at the time of writing was showing as out of stock; and the Feather RP2040 with DVI Output Port is listed as "coming soon" with a notification list available on the product page.