Ok, so when I plug my board in, I get:
- Arduino infinity logo animation with dots inside the loops
- heartbeat logo with 2 beats
- matrix goes blank
arduino-cli then reports as follows:
$ arduino-cli board list
Port Protocol Type Board Name FQBN Core
/dev/ttyACM0 serial Serial Port (USB) Arduino UNO Q arduino:zephyr:unoq arduino:zephyr
/dev/ttyS0 serial Serial Port Unknown
I am running this on Linux so the port names will be different, but as you can see, it reports the UNO Q on port /dev/ttyACM0. If I reconnect the network then it also reports an IPv6 network address:
$ arduino-cli board list
Port Protocol Type Board Name FQBN Core
fe80::e32c:d942:7726:b33e network Network Port Arduino UNO Q arduino:zephyr:unoq arduino:zephyr
/dev/ttyACM0 serial Serial Port (USB) Arduino UNO Q arduino:zephyr:unoq arduino:zephyr
/dev/ttyS0 serial Serial Port Unknown
Evidently then, the arduino-cli also searches the local network when it is available.
Even with the network disconnected, AppLab is able to detect the UNO Q when it is connected to the PC only directly via a USB cable.
While still connected to USB only and the network connection disabled, I ran an ip addr to list my network interfaces. It did not show any local Ethernet interface being exposed by the UNO Q over the direct to PC USB connection.
On Linux there are two tools for working with mDNS: avahi-utils and mdns-scan. I tried both of them and neither reported anything. This was as expected, because mDNS is a network protocol. However, since the UNO Q board was already configured for WiFi, once the network connection was re-enabled and after a short delay, both tools were able to detect the UNO Q _arduino._tcp hostname. The avahi-utils tool reported it on both the IPv4 and IPv6 network.
If you connect a multi-port USB dongle that includes an Ethernet port, an Ethernet connection does then get exposed via the dongle, but because there is no IP address assigned to it yet, it can't communicate. However, an IP address can be assigned to the port manually from the command terminal which can be accessed either from AppLab or while working in SBC mode, although since most of us use WiFi, its probably unlikely that anyone would use that option.
So I think the answer to your questions are:
- the UNO Q does not expose an Ethernet port over a direct to PC USB connection.
- the UNO Q can only announce itself over mDNS if :
- a network has been configured and it has been given a hostname*
- it is connected to that network (e.g. WiFi)
- the PC/Laptop/Mac is also connected to the same network subnet
*not sure whether it has a default generic one?
Since the UNO Q does not expose an Ethernet port over a direct PC connection, it cannot announce itself via mDNS using that route. I didn't test whether it advertises itself over the dongle Ethernet port, although I could ping it once an IP address had been assigned to the connected interface on both the UNO Q and the PC.
