Happy making, and may your dongle always be detected.
dtoverlay=disable-bt # optional, frees up UART if needed hdmi_force_hotplug=1 hdmi_group=2 hdmi_mode=16 # 1080p 60Hz, change as needed The hdmi_force_hotplug=1 is the key—it tells the GPU to output HDMI even if no display is detected at boot. cm2 dongle support
Remember the golden rule: . Get the order right, and you’ll save hours of frustration. Happy making, and may your dongle always be detected
Here’s why people get stuck: A standard USB-C hub (like one from Anker or Dell) works with phones and laptops. Plug it into a Raspberry Pi CM4 carrier board… and nothing happens . Get the order right, and you’ll save hours of frustration
It hardwires the connections without complex negotiation, so the compute module sees a simple HDMI signal and USB data lines.
At first glance, it looks like a typo for “USB-C to HDMI.” But C2M (Computer-to-Module) dongle support is something entirely different—and if you work with developer boards like the Raspberry Pi CM4 or CM5, it’s a game-changer.
Why? Because most compute module carrier boards use the USB-C port in or dual-role mode, but they don’t implement the full Alternate Mode (Alt Mode) negotiation that commercial hubs expect.