mpy-module-mcp2515

Overview

Micropython external C module for MCP2515 (For high speed)

MCP2515 : Stand Alone CAN Controller with SPI
https://ww1.microchip.com/downloads/en/DeviceDoc/MCP2515-Stand-Alone-CAN-Controller-with-SPI-20001801J.pdf

Usage

• Micropython external module generation method
  https://micropython-docs-ja.readthedocs.io/latest/develop/natmod.html#defining-a-native-module
• Build Example

#linux

git clone https://www.github.com/micropython/micropython
cd micropython/
git clone https://github.com/Wizapply/mpy-module-mcp2515 mcp2515
cd mcp2515
make

Example micropython(.py) code:

import mcp2515
import time
from machine import Pin, SPI

sckPin = 6
mosiPin = 7
misoPin = 4
csPin = 5

spio = SPI(0, 8_000_000, sck=Pin(sckPin), mosi=Pin(mosiPin), miso=Pin(misoPin))
pin_cs = Pin(csPin, Pin.OUT)
if not mcp2515.can_init(spio,pin_cs,500000):
    print('mcp2515 error.')

mcp2515.can_filter(0x700,0x700,False)
mcp2515.can_mode(mcp2515.NormalMode)

while True:
    while mcp2515.can_recv_poling() > 0:
        data = mcp2515.can_read()
        if not data is None:
            mcp2515.can_send(0x666,data[1],0)
    time.sleep_ms(10)

Performance

Repeat: Receive to Send
CAN Config: 500000 bps Standard Frame
Send Can Frame: ID:0x777 dlc:8 byte:0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00

	Micropython scripts Only	This Codes	Performance
RP2040	270~340 Messages/s	1200~1400 Messages/s	x4.0~4.3 faster

Library used

• https://github.com/micropython/micropython
  License: https://github.com/micropython/micropython/blob/master/LICENSE
• https://github.com/MinaHBB/MCP2515
  License: https://github.com/MinaHBB/MCP2515/blob/master/license.md
  The reason I used this library is to generate native mpy using C language.