No longer works on Pico W

[dhalbert]

3.1.0 doesn't work on Pico W. See below. Tried with 9.0.4 and 9.1.0-beta.1. I am guessing the problem is the .connect(). 3.1.0 does work on ESP32-S3 9.1.0-beta.1

Traceback (most recent call last):
  File "code.py", line 39, in <module>
  File "adafruit_ntp.py", line 92, in datetime
BrokenPipeError: 32

tagging @justmobilize

[b-blake]

@dhalbert, Thank you.

[justmobilize]

Confirmed on a Pico W

Works (old):

with self._pool.socket(self._pool.AF_INET, self._pool.SOCK_DGRAM) as sock:
    sock.settimeout(self._socket_timeout)
    sock.sendto(self._packet, self._socket_address)
    sock.recv_into(self._packet)

Fails (new):

with self._pool.socket(self._pool.AF_INET, self._pool.SOCK_DGRAM) as sock:
    sock.settimeout(self._socket_timeout)
    sock.connect(self._socket_address)
    sock.send(self._packet)
    sock.recv_into(self._packet)

The BrokenPipeError is on the sock.send(self._packet).

I'm guessing it's not keeping the UDP connection alive?

[anecdata]

there's no actual connection to keep alive? maybe some low-level issue in raspberrypi .send

[justmobilize]

Yeah, wrong choice of words. More like still knowing about it.

[anecdata]

MICROPY_PY_LWIP_SOCK_RAW is 1...

        case SOCKETPOOL_SOCK_DGRAM:
        #if MICROPY_PY_LWIP_SOCK_RAW
        case SOCKETPOOL_SOCK_RAW:
        #endif

does that make the DGRAM case a NOP? (edit: n/m, I guess not)
https://github.com/adafruit/circuitpython/blob/0f0509035329e933e5348cf4731f6146f012ce5a/ports/raspberrypi/common-hal/socketpool/Socket.c#L1134

[justmobilize]

If you look at sendto, it uses the IP, send passes null

[justmobilize]

Easiest fix would be to check for sento and use it

cc @jepler

[anecdata]

I think NULL is correct for RAW (for port, anyway)

I'm guessing RAW doesn't work either

[justmobilize]

In sendto it passes the IP for raw also

[justmobilize]

@dhalbert and @jepler I see 3 options:

1. Check for sendto
2. Add a UDP only sendto to esp32spi (could be expanded in the future)
3. Update send for the pico w to work

I can do 1 or 2, one of you would need to do 3.

Let me know, if it's on me will fix tomorrow.

[dhalbert]

tagging @jepler here re

3. Update send for the pico w to work

[dhalbert]

The CPython examples I see all use .sendto() for UDP. The fastest fix is to use .sendto() if it exists, and not connect(), as it was before. Then .sendto() can be implemented on esp32spi and the pico w impl can be fixed later.

As to whether you connect or not, it's more complicated than one might think:
https://blog.cloudflare.com/everything-you-ever-wanted-to-know-about-udp-sockets-but-were-afraid-to-ask-part-1/

[justmobilize]

@dhalbert so are you good with me:

1. adding sendto to esp32spi
2. after that is released, switching to sendto here?

[dhalbert]

If you already know how to do sendto right away on ESP32SPI, that sounds fine. Then you'd remove .connect(), I assume. If it's not clear about doing sendto, I'd say do the workaround in the library for now while you work on sendto. That will make the library backward compatible with multiple versions.

[justmobilize]

@dhalbert it would literally be adding:

    def sendto(self, data, address):
        self.connect(address)
        self.send(data)

I've already tested and works great. I imagine that there could be other cases it doesn't work, but can tackle those when it happens.