Hardware, Kernel#

MCP2515: Schematic#

From http://lnxpps.de/can2udpe/openwrt/

../../../../../../_images/Schematic-gimped.png

MCP2515: Soldering#

../../../../../../_images/mcp2515-top.jpg ../../../../../../_images/mcp2515-bottom.jpg

MCP2515: SPI#

  • SPI: asymmetric (Master/Slave)

    • MOSI, MISO, SCLK: SPI lines

    • Chip Select (slave select)

  • Notification to master

    • Interrupt

    • Arbitrary GPIO

 ../../../../../../_images/SPI_three_slaves.png

MCP2515: Raspberry#

  • Broadcom BCM2835

    • 2 SPI master, one available over 40-pin header

    • 2 chip select ⟶ CE0 (“Chip Enable”)

    • Tons of GPIO ⟶ GPIO25 used as interrupt pin

  • Power supply

    • 3.3V for MCP2515

    • 5V for transceiver

 ../../../../../../_images/raspi-v2-p1-pinout-gimped.png