Did exactly this on the roof lights over our paint shop canteen two years ago. What you want is the window maker’s KLF 200 interface (the io-homecontrol gateway with a LAN port). You pair each window into it like you would a new keypad, then it gives you a local API on the LAN. On the Pi there’s a Python library, pyvlx, that talks to it. Update the KLF 200 to the current firmware first, the old one has no API, and connect it by cable, not its own Wi-Fi.

Then the Pi does the rain logic locally, I would not run “close on rain” through the cloud, it has to work when the internet is down:

if rain_contact_closed() and any_open():
    await pyvlx.nodes[n].close(wait_for_completion=False)
# every 30 s, and after each move:
payload = {f"win{n:02d}.pos": node.position.position_percent for n, node in enumerate(nodes)}
mqtt.publish("v1/telemetry", json.dumps(payload), qos=1)

Positions come back from the windows so you get real feedback, 0 = closed. For the open/close buttons on the dashboard, add commands like win.close with a window number parameter to the Pi’s device profile, handle them on v1/rpc/req/+ and answer on the same id. Board controls can only send Basic tier commands from the profile’s catalogue, which is fine for this. See Control cards.

The KLF 200 only takes a couple of API connections at a time, so keep one long-lived connection in your script.

Daniel’s question is the right first step. No driver is needed on macOS, avrdude talks to the USBasp through libusb, which Homebrew installs with it. If System Information > USB doesn’t list “USBasp” at all, it’s the adapter, not avrdude. I had exactly this with two cheap USB-C adapters at our plant: the USBasp is a low-speed USB device with the firmware bit-banging USB, and some USB-C adapters and hubs don’t enumerate those reliably. A powered USB-A hub between the adapter and the USBasp fixed it for me, so did a different (Apple) adapter.

Once it’s found, the next error you’ll probably meet on fresh chips is this:

avrdude: warning: cannot set sck period. please check for usbasp firmware update.
avrdude: error: program enable: target does not answer (0x01)

A new 328P runs at 1 MHz from the internal oscillator, and the default ISP clock is too fast for it. Slow it down:

avrdude -c usbasp -p m328p -B 32 -U lfuse:w:0xFF:m -U hfuse:w:0xDE:m -U efuse:w:0xFD:m
avrdude -c usbasp -p m328p -B 4  -U flash:w:rs485node.hex:i

(those fuses are for an external 16 MHz crystal, check yours before you write them). The “cannot set sck period” warning is the old USBasp firmware talking, harmless as long as -B works; on older ones the slow-clock jumper does the same.