Display in separate module

[GEspi.19]

Lets say I need to separate module, one will contain the pcb with mpu and other IC, the second will contain a touchscreen display and sensors. The modules are 2 meters apart. What should I use hdmi or mipi? How do I send mipi over distance?

[PatrickF · Accepted solution]

HDMI will work for sure, but usually HDMI display are more expensive than few inches native DSI panels.

DSI is usally restricted to very short distances (usually below 20cm), there is some DSI retimer circuits which could help to work with longer cables (need to ask 3rd party to see if it could work for 2 meters). Need also to ensure Linux drivers for those components are provided.

You might need also to reduce DSI frequency (and so the display resolution and/or frame rate) to achieve such long range.

I think you also have sideband signals for touchscreen and sensors which need to be taken into account (e.g. an I2C could be expandable to 2meters, but need also some careful design).

Don't know your constrains or use cases, but maybe you could think about moving the MPU close to the display and use e.g. Ethernet to connect to main module (maybe using an MCU on that side). This might be a more robust approach using standard cheap cables.