This allows the stream to be set to `None`, which essentially stops all PPP
communication without disconnecting the session.
This allows replacing the stream on-the-fly to suspend it, for example to
send AT commands to a modem without completely disconnecting and
re-establishing the PPP connection:
uart = ppp.config('stream')
ppp.config(stream=None)
uart.write(b'+++')
# do some AT commands
uart.write(b'ATO\r\n')
ppp.config(stream=uart)
Any attempted communication by PPP while the stream is not connected will
register as simple packet loss to the LwIP stack because we return 0 for
any write calls, and protocols like TCP will then automatically handle
retrying.
Signed-off-by: Daniël van de Giessen <daniel@dvdgiessen.nl>
This makes the stream that the PPP object wraps, which is normally only set
once via the constructor, accessible and configurable via the
`ppp.config()` method.
Signed-off-by: Daniël van de Giessen <daniel@dvdgiessen.nl>
This commit adds a new `network.PPP` interface which works on any port that
has bare-metal lwIP, eg rp2, stm32, mimxrt.
It has been tested on stm32. A board needs to enable
`MICROPY_PY_NETWORK_PPP_LWIP` and then it can use it as follows:
import network
ppp = network.PPP(uart)
ppp.connect()
while not ppp.isconnected():
pass
# use `socket` module as usual, etc
ppp.disconnect()
Usually the application must first configure the cellular/etc UART link to
get it connected and in to PPP mode first (eg ATD*99#), before handing over
control to `network.PPP`.
The PPP interface automatically configures the UART IRQ callback to call
PPP.poll() on incoming data.
Signed-off-by: Damien George <damien@micropython.org>
