Ilies AllaliThe onboard screen of a mobile power station
Seven views, their states and their assets, integrated into the machine's firmware.
For its V2, the ECHO-5 (7 kWh / 5 kW) drops the off-the-shelf Victron display in favour of its own 5-inch touchscreen and an interface designed by Mute. I built the complete system: screens, navigation, components and their states, down to the assets integrated into the firmware.
The context
The ECHO-5 V1 carried the Victron control screen, the inverter's own: complete, but complex and unrelated to the brand. For the V2, the engineering team changed the hardware and handed me the interface for the new display: a 5-inch touch LCD (800 x 480), driven by an ESP32 microcontroller. The usage context is unforgiving: a site operator, often wearing gloves, reading the screen from a distance, from full sun to shade. And an LCD, not an OLED: contrast is a physical constraint before it is an aesthetic choice.
The framing
Before drawing anything, two questions for the embedded engineer: bitmap fonts or vector? Touch or display only? The answers change the state logic of the entire interface. Then a table of stories built with the CTO: every piece of information (voltage, power figures, runtime, alerts) described, prioritised and assigned to its screens. We decided what shows where before talking about design. That framing is what made it possible to settle things fast: state of health and cycle count removed (a source of confusion), temperature displayed only in an alert.
The screen system
Seven screens cover the life of the machine: startup, dashboard, charging, screen standby, system standby, critical alert and alert log. The dashboard keeps the mental model installed by years of Victron: inputs on the left (mains, solar, generator), battery in the centre, outputs on the right. And a distinction the field forces on you: screen standby (minimal display, machine active) is not system standby (everything shut down to save energy). Two machine states, two screens.
The decisions the field forced
The reviews with the team hardened everything. Enormous figures, 5 mm minimum on the display. Light mode by default, because an LCD in full sun makes dark unreadable. Touch targets sized for gloves. And one principle: the screen follows the state of the machine instead of making the operator navigate. A minor alert shows in yellow on the dashboard without changing screen; a blocking alert switches to a dedicated screen, orange or red depending on severity.
The details that ship it
The screens are prototyped in HTML and iterated with AI: the render is pixel-accurate to the target display, and the developer gets an executable reference they read as code, not an image to interpret. A unique QR code per machine on the error screen: scanning it opens a support ticket with the serial number. A French/English switch at the top of the screen. Every component delivered with its states (normal, pressed, disabled), PNGs tested on the real display before sign-off, and the assets exported for firmware integration (Squareline Studio, LVGL). The design stops exactly where the code starts.
The result
The interface is integrated into the ECHO-5 V2, whose electronic development is being completed. And it keeps living: new screens are added as the machine gains modes (solar production, generator). An interface you understand without a manual, drawn with the firmware's constraints rather than against them.