Communication with the smartphone is one of the most important features of the LumiBee. We evaluated different communications protocols, including Bluetooth (we used Bluetooth for the New LumiFold TB for example), USB, and others; but we wanted to extend the compatibility of the LumiBee design with as many phones as possible; and to be extremely simple as well. Things too complicated often have many side problems that take lot of times to figure it out.

We had this idea: every smartphone has a built-in flash for the rear camera, and access it is quite simple in Android studio. So why not reduce the communication protocol between the LumiBee and the smartphone to the bare minimum? This is why we used a quick blink of the flash to say “go up 1 layer in the Z axis” and 2 quick blinks to say “print is finished, put the tray completely out of the resin”?

The LumiBEE PCB has an LDR (light) sensor, able to detect light intensity, on the bottom of a pegboard-like segment of the Lumibee, under the phone. The sensor is able to detect these two basic commands, and you can move the LDR in order to align it with the flash of your phone. Nice solution, simple, and it works like a charm!