PWRCAN

The PWRCAN is a CAN interface that can be used to communicate with other devices.

The following are the host’s support for PWRCAN:

Controller

Status

PowerHub

✔

UiFlow2 Example

pwrcan_send_receive

Open the pwrcan_send_receive_powerhub_example.m5f2 project in UiFlow2.

This example demonstrates how to utilize PWRCAN interfaces to sender and receive data.

UiFlow2 Code Block:

pwrcan_send_receive_powerhub_example.png

Example output:

None

MicroPython Example

pwrcan_send_receive

This example demonstrates how to utilize PWRCAN interfaces to sender and receive data.

MicroPython Code Block:

 1# SPDX-FileCopyrightText: 2026 M5Stack Technology CO LTD
 2#
 3# SPDX-License-Identifier: MIT
 4
 5import os, sys, io
 6import M5
 7from M5 import *
 8from hardware import PWRCAN
 9
10
11pwrcan = None
12
13
14def setup():
15    global pwrcan
16
17    M5.begin()
18    Power.setExtPortBusConfig(direction=1, output_enable=1, voltage=12000, current_limit=232)
19    pwrcan = PWRCAN(id=0, port=(40, 39), mode=PWRCAN.NORMAL, baudrate=25000)
20
21
22def loop():
23    global pwrcan
24    M5.update()
25    if BtnA.wasPressed():
26        pwrcan.send("uiflow2", 0, timeout=0, rtr=False, extframe=False)
27    if pwrcan.any(0):
28        print(pwrcan.recv(0, timeout=5000))
29
30
31if __name__ == "__main__":
32    try:
33        setup()
34        while True:
35            loop()
36    except (Exception, KeyboardInterrupt) as e:
37        try:
38            from utility import print_error_msg
39
40            print_error_msg(e)
41        except ImportError:
42            print("please update to latest firmware")

Example output:

None

API

PWRCAN

class PWRCAN(id, mode, tx, rx, prescaler=32, sjw=3, bs1=15, bs2=4, triple_sampling=False)

Initialise the CAN bus with the given parameters.

Parameters:

  • id (int) – The CAN bus ID.

  • mode (int) – One of NORMAL, NO_ACKNOWLEDGE, LISTEN_ONLY.

  • tx (int) – The pin to use for transmitting data.

  • rx (int) – The pin to use for receiving data.

  • prescaler (int) – The value by which the CAN input clock is divided to generate the nominal bit time quanta. Value between 1 and 1024 inclusive for classic CAN.

  • sjw (int) – The resynchronisation jump width in units of time quanta for nominal bits; value between 1 and 4 inclusive for classic CAN.

  • bs1 (int) – Defines the location of the sample point in units of the time quanta for nominal bits; value between 1 and 16 inclusive for classic CAN.

  • bs2 (int) – Defines the location of the transmit point in units of the time quanta for nominal bits; value between 1 and 8 inclusive for classic CAN.

  • triple_sampling (bool) – Enables triple sampling when the TWAI controller samples a bit.

UiFlow2 Code Block:

init.png

MicroPython Code Block:

from hardware import PWRCAN

can = PWRCAN(id=0, port=(40, 39), mode=PWRCAN.NORMAL, baudrate=25000)

PWRCAN class inherits CAN class. See hardware.CAN for more details.