import canio
import digitalio
# If the CAN transceiver has a standby pin, bring it out of standby mode
if hasattr(board, 'CAN_STANDBY'):
standby = digitalio.DigitalInOut(board.CAN_STANDBY)
standby.switch_to_output(False)
# If the CAN transceiver is powered by a boost converter, turn on its supply
if hasattr(board, 'BOOST_ENABLE'):
boost_enable = digitalio.DigitalInOut(board.BOOST_ENABLE)
boost_enable.switch_to_output(True)
# Use this line if your board has dedicated CAN pins. (Feather M4 CAN and Feather STM32F405)
can = canio.CAN(rx=board.CAN_RX,
tx=board.CAN_TX,
baudrate=250_000,
auto_restart=True)
# On ESP32S2 most pins can be used for CAN. Uncomment the following line to use IO5 and IO6
#can = canio.CAN(rx=board.IO6, tx=board.IO5, baudrate=250_000, auto_restart=True)
listener = can.listen(matches=[canio.Match(0x408)], timeout=.9)
old_bus_state = None
old_count = -1
while True:
bus_state = can.state
if bus_state != old_bus_state:
print(f"Bus state changed to {bus_state}")
old_bus_state = bus_state
led.direction = digitalio.Direction.OUTPUT
sleep = 2.0
# If the CAN transceiver has a standby pin, bring it out of standby mode
if hasattr(board, 'CAN_STANDBY'):
standby = digitalio.DigitalInOut(board.CAN_STANDBY)
standby.switch_to_output(False)
# If the CAN transceiver is powered by a boost converter, turn on its supply
if hasattr(board, 'BOOST_ENABLE'):
boost_enable = digitalio.DigitalInOut(board.BOOST_ENABLE)
boost_enable.switch_to_output(True)
# Use this line if your board has dedicated CAN pins. (Feather M4 CAN and Feather STM32F405)
can = canio.CAN(rx=board.CAN_RX, tx=board.CAN_TX, baudrate=250_000, auto_restart=True)
old_bus_state = None
count = 0
while True:
bus_state = can.state
if bus_state != old_bus_state:
print(f"Bus state changed to {bus_state}")
old_bus_state = bus_state
now_ms = (time.monotonic_ns() // 1_000_000) & 0xffffffff
print(f"Sending message: count={count} now_ms={now_ms}")