// application note

AN0017 Streaming images from an STMicroelectronics VD55G1 over I3C with the Binho Supernova

The STMicroelectronics VD55G1 is a monochrome image sensor that can send its image over I3C, one line at a time, instead of over MIPI CSI-2. Each line is held for about 340 microseconds before the next one replaces it, and a single read issued from a PC over USB took 3.6 to 4.3 milliseconds on our bench, so a PC cannot read the image by issuing I3C reads itself. This application note shows how a Binho Supernova does those reads on the adapter, paced by a timer from one GPIO edge per frame, and returns whole frames to the PC over USB. On the bench it streams 160x120 8-bit frames at 9.8 frames per second. A Python capture utility and a live viewer are supplied; they produced the outputs in Sections 2 and 6.

Products: Binho Supernova
Protocols: I3C
Topics: Image Sensors
Revision: Rev 1.0 · November 6, 2026

// outcomes

What you'll walk away with

This document covers:

booting the VD55G1 from a PC: reset, enumeration, patch download and configuration
the GPIO0 edge that starts a frame's readout
the Supernova command I3C_CONTROLLER_CAPTURE_LINES, which reads every line of a frame on the adapter and returns the frame over USB
capturing still frames to PNG files, and a live view at 9.8 frames per second
the line timing window, as measured

It does not cover the sensor's MIPI CSI-2 output, color sensors, resolutions above 160x120, or sensors that signal frame start with an in-band interrupt instead of a GPIO.

// background

Background

An image sensor normally sends pixels over MIPI CSI-2, which needs a host with a camera receiver. The VD55G1 can also send its image over I3C, the same two-wire bus that configures it. That makes a camera reachable from anything that speaks I3C, including a USB host adapter, with no camera interface on the host side.

The catch is timing. The sensor exposes one line at a time in a register window, and the next line replaces it about 340 microseconds later. A 160-byte read of that window issued from a PC took 3.64 ms at best and 4.00 ms at the median over 200 reads on our bench, so most lines are gone before the PC can ask for them. The reads have to be issued by something close to the bus. In this note that is the Supernova's own firmware.

// applicable devices

Applicable devices

Family	Example parts	Identifier	Basis
STMicroelectronics VD55G1	VD55G1 cut 2.0 on a Gilisymo LS-CAM-I3C board	Model `S5G1` at register 0x0000, cut 0x20 at 0x0004	Tested

// what's covered

What's covered in the note

01 Introduction
02 System overview
03 Hardware setup
04 Software setup
05 The capture command
06 Procedure
07 Measured results
08 Troubleshooting

The full procedure, measured results, and reference code are in the PDF and the assets archive.

// materials

What you'll need

Binho Supernova USB host adapter for I3C, I2C, SPI & UART View product

Software Mission Control 3 or the Cosmic SDK (Python, C / C++ / C#). Get the software

Files The reference scripts and assets used in this note. Download the assets

// our edge

We don't just follow the I3C spec.

We don't watch from the sidelines. Plugfest after plugfest, our team is in the room where vendor I3C implementations come together — finding edge cases, debugging quirks, and validating real silicon against the spec.