Two modules can share a sensor and still be different products. The difference is often the pipe. USB camera modules enumerate as UVC. MIPI camera modules land on CSI-2 lanes and expect your SoC to own clocks, drivers, and often the ISP.
USB, when it is the honest choice
You want a camera that works on Tuesday: a PC, a kiosk, a medical cart, a USB 2.0 hub. The ISP and UVC stack already decided colour and exposure. That is a product, not a failure, as long as you do not then ask why auto-exposure panics at a window. Bandwidth is the tax. USB 2.0 will not carry a fat 4K RAW stream. Plan the format.
MIPI, when you need the wells
MIPI CSI-2 is a short, fast, low-power link from the die to the processor. Raspberry Pi, NVIDIA Jetson, and Rockchip boards speak it. You get lanes, bit depth, and a chance at RAW. You also get driver work, MCLK, and a flex that has to be the right length. Factory modules are built this way. A 15-pin hobby cable is not the same contract as a 30-pin board-to-board.
A simple rule
- Host is Windows or Linux desktop, and you need it this week: start USB.
- Host is Pi, Jetson, or an OEM SoC, and you care about latency or RAW: start MIPI.
- Need both? That is two SKUs, or a module that can do either, not one magical connector.
The custom camera module flow starts with this sentence. Interface is not an accessory. It is the product.