GTS iMapla3

The MMI (man machine interface) is a device to control and indicate errors of magnets within the cockpit of excavators on junkyards. This project was built in cooperation with the company GTS to redesign this existing device, implementing ergonomic aspects. In this solution, the interface was reduced to be as understandable as possible, so every excavator driver knows instantly what to do in case of a problem. Additionally the focus was set on the economical as well as the environmental production of the MMI.

A huge step

Comparing the old and the redesigned MMI, it immediately shows how the new structure of the interface helps to understand the device better. Simpler graphics and less contrast help to quickly see what is shown.

For example you can see here the different status for powering the magnet in regular on/off as well as intensifying mode. Also errors are shown, at first an overloaded magnet (old MMI: LED 5, new MMI: weight icon) afterwards a specific communication error. Here we focused on more detailed troubleshooting by adding an less intuitive errorcode which is more helpful for maintenance staff (old MMI: blinking LED 4, new MMI: warning icon + F2).

Before we started we analysed how the current device worked.


Throughout the developing process, the existing device had been refurbished using foam mock-ups and more detailed models until the fully redesigned prototype had been achieved.

Into every detail

To know what actually had to be improved, the old device needed to be observed in every detail to understand which functions are really needed and which ones could be reduced. In addition to that, new requirements by the company needed also to be implemented.

Using an Arduino the interaction could be prototyped.


We built a prototype using an Arduino Uno to test the behaviour of the buttons as well as the readability of the icons with backllight.


To make sure, that the new interface will fit perfect for the users needs, we talked to excavator drivers who use the MMI every day. Very close to their needs and perfectly for the needed environment the new device is designed for its use.