Boards (Watterott)

Board Support Package for Arduino IDE v1.8+.


Add the following URL to the Arduino Boards Manager (File->Preferences):


Then open the Arduino Boards Manager (Tools->Board->Boards Manager) and install the Watterott AVR Boards, Watterott SAMD Boards and Arduino SAMD Boards.

If you want to use the ATTinyCore from Spence Konde for the Nanite boards, then also install it via the Arduino Boards Manager. Here is the URL:

Boards Manager

Known Issues


Sometimes the driver for the USB Bootloader (Caterina or Micronucleus) is not loaded correctly. This is the case when Done uploading. is not shown after the upload process. Check the driver state in the Device Manager, when the Bootloader is active (Caterina after the Upload is started and Micronucleus after a reset). If you cannot install the driver on Windows 8 or higher then deactivate the driver signature enforcement.

Under Windows sometimes the automatic removable drive indexing prevents the usage of Mass-Storage Bootloaders (MSC), because the index service writes to the device wrong data. This can be disabled in the registry under HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search with DisableRemovableDriveIndexing=1 (registry file).


The Modem Manager can cause problems, because it detects Serial Ports (e.g. of the USB Bootloader) as a modem. So we recommend to uninstall/remove the Modem Manager:

  $ sudo apt-get uninstall modemmanager

As alternative it is also possible to add a backlist rule for the USB device to the file 77-mm-usb-device-blacklist.rules.

Micronucleus Bootloader

The Micronucleus bootloader is not started automatically. You have to press the reset switch to activate the bootloader after Uploading… is shown in the Arduino IDE.

If the error Please select a Port before Upload is shown and no port can be selected, then edit the file preferences.txt in the user directory and add a default serial port with serial.port=COM1. The file can be located, by clicking on the link at the bottom of the preferences window (File->Preferences) and only change the file, when the IDE is not running.

On upload/connection problems try a short USB cable (<30cm).

The Micronucleus upload tool needs root permission to run and so the Arduino IDE has to be started with sudo or you can also create a rule to allow non-root users access to the Micronucleus USB device. For this run one of the commands - depending on your system:

  $ sudo nano /etc/udev/rules.d/49-micronucleus.rules


  $ sudo nano /lib/udev/rules.d/49-micronucleus.rules

and add the following lines to the file:

SUBSYSTEMS=="usb", ATTRS{idVendor}=="16d0", ATTRS{idProduct}=="0753", MODE:="0666", ENV{MTP_NO_PROBE}="1"
KERNEL=="ttyACM*", ATTRS{idVendor}=="16d0", ATTRS{idProduct}=="0753", MODE:="0666", ENV{ID_MM_DEVICE_IGNORE}="1"

Reload udev rules:   $ sudo udevadm control --reload-rules

VCP+MSC Bootloader

The bootloader can be activated via the Arduino IDE or by doing two reset in 0.5s (double pressing reset switch).

When the bootloader is active then a new program can be loaded via the Arduino IDE and the serial port or via the mass storage device. For the mass storage device just copy a new binary file (.bin) to the drive.

On Linux/Mac the dd command can be used to write the firmware program: $ dd if=APP.BIN of=/media/DRIVENAME/APP.BIN conv=notrunc

A binary file can be generated and exported in the Arduino IDE with Sketch->Export compiled Binary command.


See Troubleshooting page.