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MCP2515

datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/20001801H.pdf

This module contains the driver for Microchip MCP2515, a second generation stand-alone CAN controller. It is pin and function compatible with the MCP2510 and also includes upgraded features like faster throughput, databyte filtering, and support for time-triggered protocols (datasheet_).

Class MCP2515

MCP2515(dvr, cs, rst=None, clk=800000)
Creates an instance of the MCP2515 class. This class allows the control of MCP2515 devices.

  • drv is the SPI Driver used '(SPI0, ...)'.
  • cs is the chip select of the SPI driver.
  • rst is the Reset pin . Default None.
  • clk is the clock speed, default 800 kHz.

method init

init(idmode, speed, clock)
Initializes the MCP2515 chip.

  • idmode set the RX buffer id mode (selectable from mcp2515.MCP_STDEXT, mcp2515.MCP_STD, mcp2515.MCP_EXT, or mcp2515.MCP_ANY.

  • speed set the speed of the CAN communication.

  • clock set the clock of the CAN Communication.

    Possible combination of values for Clock and Speed are:

    • Clock → 8MHZ

      Clock Speed
      "8MHZ" "5KBPS"
      "8MHZ" "10KBPS"
      "8MHZ" "20KBPS"
      "8MHZ" "31KBPS"
      "8MHZ" "33KBPS"
      "8MHZ" "40KBPS"
      "8MHZ" "50KBPS"
      "8MHZ" "80KBPS"
      "8MHZ" "100KBPS"
      "8MHZ" "125KBPS"
      "8MHZ" "200KBPS"
      "8MHZ" "250KBPS"
      "8MHZ" "500KBPS"
      "8MHZ" "1000KBPS"

    • Clock → 16MHZ

      Clock Speed
      "16MHZ" "5KBPS"
      "16MHZ" "10KBPS"
      "16MHZ" "20KBPS"
      "16MHZ" "31KBPS"
      "16MHZ" "33KBPS"
      "16MHZ" "40KBPS"
      "16MHZ" "50KBPS"
      "16MHZ" "80KBPS"
      "16MHZ" "100KBPS"
      "16MHZ" "125KBPS"
      "16MHZ" "200KBPS"
      "16MHZ" "250KBPS"
      "16MHZ" "500KBPS"
      "16MHZ" "1000KBPS"

    • Clock → 20MHZ

      Clock Speed
      "20MHZ" "40KBPS"
      "20MHZ" "50KBPS"
      "20MHZ" "80KBPS"
      "20MHZ" "100KBPS"
      "20MHZ" "125KBPS"
      "20MHZ" "200KBPS"
      "20MHZ" "250KBPS"
      "20MHZ" "500KBPS"
      "20MHZ" "1000KBPS"

method set_mode

set_mode(mode)
Sets the operation mode of the MCP2515.

  • mode operation mode ("NORMAL", "SLEEP", "LOOPBACK", "LISTENONLY", "CONFIG", "POWERUP", "ONE_SHOT").

method init_mask

init_mask(num, data, ext)
Initializes Masks.

  • num 0 to set mask 0 on RX buffer, 1 to set mask 1 on RX buffer.

  • data Data Mask.

  • ext 0 for standard ID, 1 for Extended ID.

method init_filter

init_filter(num, data, ext)
Initializes Filters.

  • num number of filter to be set in RX buffer (from 0 to 5).

  • data Data Filter.

  • ext 0 for standard ID, 1 for Extended ID.

method send

send(canid, data, ext=None)
Sends CAN messages.

  • canid ID of the CAN message (bytearray of 4 bytes).

  • data Data to be sent (list of 8 bytes).

  • ext 0 for standard ID, 1 for Extended ID (default None - auto detected).

method recv

recv()
Receives CAN messages returnung CAN id value and related data message.

Returns canid, msg.

Example

from components.mcp2515 import mcp2515  
...
can = mcp2515.MCP2515(SPI0, D17, D16, clk=10000000)
can.init(mcp2515.MCP_ANY, "500KBPS", "16MHZ")
can.set_mode("NORMAL")
...     
can.send(canid, data)