Appliance

The appliance is a dedicated board that runs nothing but the EtherCAT master. The board owns the cable to the AUTD3 devices, and your machine connects over TCP with RemoteLink.

Only the Raspberry Pi 4 (RP4) is currently supported.

What you need

Board	Raspberry Pi 4 Model B
microSD card	8GB or larger
Power supply	A USB-C supply for the RP4 (5V/3A)
USB Ethernet adapter	The second wired port, used for the host. AX88179-based adapters are the ones we have tested
Ethernet cables	Two, CAT 5e or better (one for the AUTD3 devices, one for the host)

Getting the image

The SD image is distributed on a Release page separate from the SDK itself. Open appliance-v0.6.0 and download autd3-appliance-rp4-<version>-<date>.img.xz. Use the image whose version matches the client you use.

Writing the card

With Raspberry Pi Imager, pick the .img.xz as is under “Use custom”.

Caution

Do not use the Imager’s OS customisation (username, password, Wi-Fi, SSH). The customisation is either ignored or may stop the board from booting.

On Linux and macOS, dd works too.

xz -dc autd3-appliance-rp4-*.img.xz | sudo dd of=/dev/sdX bs=4M conv=fsync status=progress

First boot

The first boot takes about a minute.

Discovering the appliance from the host tells you whether it came up.

autd3-appliance scan

autd3-appliance is bundled with autd3-console (Console). Pressing “Scan” on the Appliance tab of autd3-console does the same thing.

Getting started

1. Connect the RP4’s onboard Ethernet port to the AUTD3 devices, and connect the host directly to the RP4 with an additional USB Ethernet adapter
   • The RP4 and the host may also be connected over a LAN (Wi-Fi works too, see below), but a direct cable is recommended
2. Power on the AUTD3 devices and the board
3. Connect from the host with RemoteLink

Rust

let option = RemoteLinkOption::discover()?;

Python

option = RemoteLinkOption.discover()

C#

var option = RemoteLinkOption.Discover();

Dashboard

http://autd3-<serial no.>.local:8081/ shows the state of the bus. (The address is in the scan result.)

The following operations are available.

Status	Whether the bus is open, the EtherCAT state of each device, phase excursions and exchange times, the connected client, the uplink addresses and Wi-Fi state
Bus	Open, close, count the devices
Config	Read and replace the config file (takes effect after a restart)
Logs	The board’s log
Maintenance	Restart the server, reboot or power off the board, update the server binary, set or remove Wi-Fi credentials

The same operations are available from the autd3-appliance command. Discovery, status, opening and closing the bus, and restarting are also on the Appliance tab of autd3-console.

autd3-appliance scan
autd3-appliance status
autd3-appliance config get > appliance.toml
autd3-appliance config set appliance.toml
autd3-appliance logs --lines 500

Wi-Fi

To use Wi-Fi, connect over Ethernet first (a direct cable or a LAN both work), then store the credentials.

autd3-appliance wifi set --ssid <SSID> --psk <PASSPHRASE> --country JP

Pass a two-letter country code to --country (JP for Japan). Leave it out and the 5GHz band and channels 12/13 stay unavailable.

The uplink line of autd3-appliance status says whether it associated. radio blocked means the radio is disabled on the board, and domain unset means no country code is stored.

Wi-Fi is slower and less stable than Ethernet, so a wired connection is recommended if possible.

Turning Wi-Fi off

wifi forget removes the stored credentials.

autd3-appliance wifi forget
autd3-appliance wifi forget --radio-off

With --radio-off the radio itself is turned off on top of removing the credentials.

Both are refused unless the board is reachable over Ethernet. Add --force to turn it off over Wi-Fi anyway.

When the API can no longer undo it

If wifi forget --force left the board unreachable, or neither Ethernet nor Wi-Fi comes up, you have to fix it by editing the SD card directly.

Insert the card into a host, and add this line at the end of config.txt on the boot partition to stop the radio.

dtoverlay=disable-wifi

Remove the line to bring the radio back. To drop only the credentials, delete network/autd3-wifi.nmconnection and wifi-radio-off from the autd3-data partition.

Security

Neither the control API nor the Remote Link has authentication.

To turn off only the write side, set control.allow_admin to false. Status and opening or closing the bus keep working; rebooting the board, powering it off, binary updates, Wi-Fi setup and removal, and replacing the config are refused. Restarting the server process is not refused. Setting control.enabled to false disables HTTP communication entirely.

Configuration

The config file is /data/autd3/remote-server.toml on the board. Read and write it from the browser or with autd3-appliance config. Changes take effect after the server restarts.

The two keys you will mainly touch are the following.

Key	Meaning
bus.sync0_period	The bus period, 1ms by default. Lengthen it when there are many devices and the bus is unstable
bus.open_on_start	Whether to open the bus at power-on. true by default

sync0_period is best set to the smallest multiple of 500us that is longer than twice the exchange time.