To make the settings easier, we made a simple Windows application that talks to the Blub clock over the USB interface. It can set up the configuration parameters as well as update the firmware.

First, download the ZIP archive, the ZIP archive contains the Blub.exe application and HEX file with current firmware.

ZIP file contents:

Unpack it and launch the Blub.exe application, no installation is necessary. Connect the clock to the computer via the provided USB cable.


The hardware of the Blub clock is designed just like Arduino Nano (328p). Under Windows 10, the driver will be installed automatically after plugging in the clock. For manual installation or for other Windows versions please follow the instructions here:

Now we need to find the right COM port where is the clock connected. Click the refresh button and select one of the ports that are not COM1. In our case, it is COM4.

In case of a successful connection to the clock, the application will write the current clock firmware and the date when the firmware was compiled. We are connected to the clock!


To configure the clock, pick the desired option from the drop-down menus, the option will be sent to the clock immediately.

Time synchronization

Click the Sync time button to set the clock to the time from your computer.

Firmware update

To update the clock firmware, click the Update firmware button and select the new firmware HEX file (provided in the ZIP archive). The file will be loaded into the clock in around 1 minute, you can see a green line on the progress bar. The clock will restart once the update is done.