This requires the most recent libraries to work - make sure to update. If you are using a board with ESP32SPI code frozen (like the PyPortal), you'll need CircuitPython 9.1.0 Beta 3 (or newer)
I've been spending a bunch of time testing code across different MCUs and networking chips. It started with my work with Connection Manager. Then I was digging into Requests and MiniMQTT . Which of course lead me to places like NTP, AzureIoT and AWS_IOT.
As I jumped around, I needed a way to always get the right radio. Sometimes it's native WiFi, which is easy: wifi.raidio, but other times, it's some SPI based FeatherWing or maybe a M4 with and AirLift (talking to you PyPortal and MatrixPortal M4)...
Introducing: get_radio
It's not perfect, and I'm guessing there are things I haven't thought of, but it works for me so far.
The only thing a normal developer, with the right libraries installed and only one radio needs to do is:
radio = get_radio()
Let's say you have native WiFi and an ESP32SPI and you want the esp?
radio = get_radio(force="esp32spi")
The nice thing is it will connect for you and everything! Store your creds as WIFI_SSID? Got you covered. What about CIRCUITPY_WIFI_SSID? Got you covered there too. What about in secrets.py? Sadly not there, settings.toml is the way to go.
Now let's say you aren't using a FeatherWing, or you are connecting things to different pins? Well your set there too!
For the ESP32SPI (aka AirLift) you just need to set the following in your settings.toml (just set the right pins):
ESP32SPI_CHIP_SELECT = "D13" ESP32SPI_READY = "D11" ESP32SPI_RESET = "D12"
And for a WIZnet5k, even simpler:
WIZNET_CHIP_SELECT = "D10"
So now, on a device like the PyPortal, you can simply do:
import adafruit_connection_manager
import adafruit_requests
from connection_helper import get_radio
radio = get_radio()
pool = adafruit_connection_manager.get_radio_socketpool(radio)
ssl_context = adafruit_connection_manager.get_radio_ssl_context(radio)
requests = adafruit_requests.Session(pool, ssl_context)
with requests.get("http://wifitest.adafruit.com/testwifi/index.html") as response:
print(response.text)
Oh and you know where else this works? CPython!!!
Connection Manager now has a radio that's a wrapper for the native socket and ssl methods. Adding this was a life-saver, because now for network only code, if somethings not working I can work directly in Cpython which of course is a lot faster (you just need to be careful, since if can make new sockets all day long, where your MCU can only manage a few).
So again, in CPython, just that simple get_radio() will work and you can pass that to the other helpers. Bam!
At some point, I might make this a little more formal and add it to the community bundle But until then, you can download this and save it as connection_helper.py on your CircuitPython drive:
# SPDX-FileCopyrightText: Copyright (c) 2024 Justin Myers
#
# SPDX-License-Identifier: MIT
import os
import sys
import adafruit_connection_manager
try:
import board
import busio
import digitalio
except (ImportError, NotImplementedError):
pass
is_microcontroller = sys.implementation.name == "circuitpython"
_global_found_radios = {}
_global_print = True
_global_spi = None
def enable_log(enable):
global _global_print # noqa: PLW0603 Using the global statement to update variable is discouraged
_global_print = enable
def log(value):
if _global_print:
print(value)
def get_global_spi():
global _global_spi # noqa: PLW0603 Using the global statement to update variable is discouraged
if _global_spi is None:
if getattr(board, "SCK1", None):
_global_spi = busio.SPI(board.SCK1, board.MOSI1, board.MISO1)
else:
_global_spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
return _global_spi
def get_pin(env_name, default):
pin_name = os.getenv(env_name, default)
pin = getattr(board, pin_name, None)
if pin is None:
raise ValueError(f"Pin {pin_name} for {env_name} not found")
return pin
def get_saved_radio(name):
if name in _global_found_radios:
return _global_found_radios[name]["radio"]
return None
def save_radio(name, radio, pins=None):
_global_found_radios[name] = {
"radio": radio,
"pins": pins,
}
def connect_radio(radio):
if not hasattr(radio, "connect"):
log("Radio does not need to connect")
return
if radio.connected:
log("Already connected")
return
ssid = os.getenv("WIFI_SSID")
if ssid:
password = os.getenv("WIFI_PASSWORD")
else:
ssid = os.getenv("CIRCUITPY_WIFI_SSID")
password = os.getenv("CIRCUITPY_WIFI_PASSWORD")
if ssid is None:
raise AttributeError("Can't find SSID information in settings.toml")
log(f"Connecting to SSID: {ssid}")
try:
radio.connect(ssid, password)
except TypeError:
radio.connect_AP(ssid, password)
log("Connected")
def deinit_radio(radio):
match = None
for key, data in _global_found_radios.items():
if data["radio"] == radio:
match = key
break
if match is None:
raise ValueError("Radio not found")
pins = _global_found_radios[key]["pins"]
if isinstance(pins, list):
for pin in pins:
pin.deinit()
del _global_found_radios[key]
del radio
def get_cpython_radio(raise_exception=True):
radio = get_saved_radio("cpython")
if radio:
return radio
if is_microcontroller and raise_exception:
raise RuntimeError("CPython library not found")
radio = adafruit_connection_manager.CPythonNetwork()
save_radio("cpython", radio)
log("Running CPython")
return radio
def get_esp32spi_radio(raise_exception=True):
radio = get_saved_radio("esp32spi")
if radio:
return radio
try:
from adafruit_esp32spi import adafruit_esp32spi
except ImportError as exc:
if raise_exception:
raise RuntimeError("ESP32SPI library not found") from exc
return None
if getattr(board, "ESP_CS", None) is not None:
esp32_chip_select_pin = board.ESP_CS
esp32_ready_pin = board.ESP_BUSY
esp32_reset_pin = board.ESP_RESET
else:
esp32_chip_select_pin = get_pin("ESP32SPI_CHIP_SELECT", "D13")
esp32_ready_pin = get_pin("ESP32SPI_READY", "D11")
esp32_reset_pin = get_pin("ESP32SPI_RESET", "D12")
esp32_chip_select = digitalio.DigitalInOut(esp32_chip_select_pin)
esp32_ready = digitalio.DigitalInOut(esp32_ready_pin)
esp32_reset = digitalio.DigitalInOut(esp32_reset_pin)
spi = get_global_spi()
radio = adafruit_esp32spi.ESP_SPIcontrol(
spi, esp32_chip_select, esp32_ready, esp32_reset
)
try:
radio.firmware_version
except TimeoutError as exc:
esp32_chip_select.deinit()
esp32_ready.deinit()
esp32_reset.deinit()
if raise_exception:
raise RuntimeError("ESP32SPI radio not found") from exc
return None
save_radio("esp32spi", radio, [esp32_chip_select, esp32_ready, esp32_reset])
log("Found ESP32SPI")
return radio
def get_wifi_radio(raise_exception=True):
radio = get_saved_radio("wifi")
if radio:
return radio
try:
import wifi
except ImportError as exc:
if raise_exception:
raise RuntimeError("WiFi library not found") from exc
return None
radio = wifi.radio
save_radio("wifi", radio)
log("Found native Wifi")
return radio
def get_wiznet5k_radio(raise_exception=True):
radio = get_saved_radio("wiznet5k")
if radio:
return radio
try:
from adafruit_wiznet5k import adafruit_wiznet5k
except ImportError as exc:
if raise_exception:
raise RuntimeError("WIZnet5k library not found") from exc
return None
wiznet_chip_select_pin = get_pin("WIZNET_CHIP_SELECT", "D10")
wiznet_chip_select = digitalio.DigitalInOut(wiznet_chip_select_pin)
spi = get_global_spi()
try:
radio = adafruit_wiznet5k.WIZNET5K(spi, wiznet_chip_select, is_dhcp=True)
except RuntimeError as exc:
chip_select.deinit()
if raise_exception:
raise RuntimeError("WIZnet5k radio not found") from exc
return None
save_radio("wiznet5k", radio, [wiznet_chip_select])
log("Found WIZnet5k")
return radio
def get_radio(connect=True, force=None):
radio = None
log("Detecting radio...")
if not is_microcontroller:
radio = get_cpython_radio(raise_exception=False)
if radio is None and force is None or force == "wifi":
radio = get_wifi_radio(raise_exception=force)
if radio is None and force is None or force == "esp32spi":
radio = get_esp32spi_radio(raise_exception=force)
if radio is None and force is None or force == "wiznet5k":
radio = get_wiznet5k_radio(raise_exception=force)
if radio is None:
raise RuntimeError("Cannot determine radio")
if connect:
connect_radio(radio)
return radio