Why Build a Custom HDMI Switcher?
In today's multimedia environments—be it home theaters, classrooms, or conference rooms—switching between HDMI sources is a routine requirement. Commercial HDMI switchers are available, but they often lack customization. For someone wanting more control, especially with on-screen control prompts (like source name or simple volume indicators), a DIY solution becomes not just feasible, but exciting. Enter the ADV7622BSTZ.This chip is capable of both HDMI input and output, handles HDCP decryption/encryption, and supports high-resolution audio/video. It’s a professional-grade component that gives hobbyists a serious tool for real-time HDMI signal management.
Overview of the Project
The project’s end goal is to build a sleek desktop HDMI switcher device with the following features:● Two HDMI input ports and one HDMI output port.
● A simple tactile button to toggle between HDMI sources.
● On-Screen Display (OSD) overlay showing the currently selected source.
● Visual confirmation when the HDMI link is active.
● Clean, minimalistic enclosure for use in a home media setup.
All these functions are centered around the capabilities of the ADV7622BSTZ.
Getting Started with the ADV7622BSTZ
The ADV7622BSTZ is a sophisticated IC that integrates HDMI receiver and transmitter functions, offering resolutions up to 1080p and supporting audio extraction. It’s normally used in set-top boxes, AV receivers, and professional video equipment. To build a DIY project with it, you typically need:● The ADV7622BSTZ chip (often mounted on an evaluation board unless you’re doing advanced SMT reflow).
● A regulated power supply (providing 3.3V and 1.8V).
● HDMI connectors (type A) for both input and output.
● A microcontroller or basic controller circuit to handle I2C communications and OSD trigger events.
● Some user interface components (button, LED).
● An enclosure to house the finished switcher.
In our project, we’ll assume the use of an evaluation or breakout board to simplify the setup.
Assembling the Hardware
1. HDMI Connectors and Signal RoutingThe first task is wiring the HDMI connectors properly. HDMI signals are high-speed differential pairs, so clean, impedance-controlled routing is essential. Using pre-made HDMI breakout boards for each port reduces complexity.
Each input port connects to one of the ADV7622BSTZ’s input channels. The output HDMI connector is wired directly to the output of the chip. Care is taken to keep cable lengths short to reduce signal degradation.
2. Power Supply Design
The ADV7622 requires several power rails—commonly 3.3V and 1.8V for core and IO. A dedicated power module is assembled using linear voltage regulators or DC-DC converters depending on the power efficiency goals. Clean, low-noise power is essential due to the sensitive nature of high-frequency HDMI signaling.
3. User Interface Components
A simple push button is connected to toggle input sources. An LED is added to indicate which input is currently active. These interface elements are handled by a low-end microcontroller (e.g., ATtiny or STM32, not the focus here), or by hard-wired logic if code is to be avoided entirely.
4. OSD Implementation Using ADV7622
One of the most exciting features of the ADV7622 is its built-in OSD capability. This means we can overlay graphics or text onto the HDMI video without interrupting or modifying the source content itself. For this project, a simple text banner like "Input 1" or "Input 2" is displayed briefly when switching inputs. This is configured through the chip’s OSD engine, which is controlled over I2C.
The Switching Logic
The system operates on a straightforward principle: when the user presses the button, the control logic (hardware-based or via microcontroller) sends a signal to the ADV7622 to switch its HDMI input selection. Internally, the ADV7622 handles HDCP, re-clocking, and signal re-transmission, so there's no need to process or buffer the video externally.The current input state is stored in a flip-flop or register, and the OSD is briefly activated to display a notification. This feedback makes the device feel responsive and polished.
Testing and Troubleshooting
Once assembled, the system is tested with real-world devices: Blu-ray players, game consoles, PCs, and TVs.Initial tests verify:
● Both inputs provide proper video and audio signals.
● Switching occurs without delay or signal dropouts.
● OSD overlays appear briefly and correctly on the screen.
● The HDMI output maintains signal integrity at 1080p.
If video noise or flickering is observed, grounding and shielding are checked. Inconsistent input detection usually traces back to HDCP handshaking, which is handled gracefully by the ADV7622 if its initialization is correct.
Designing the Enclosure
For aesthetics and usability, the entire circuit is housed in a custom 3D-printed or laser-cut enclosure. Openings are made for HDMI ports, the tactile switch, and an indicator LED. Inside, spacers and insulation prevent any shorts or movement.Heat management is considered as well—while the ADV7622 doesn’t generate excessive heat under normal use, a few ventilation holes ensure long-term reliability.
The final result is a compact, modern-looking device that looks right at home next to any AV receiver or game console.
Use Cases and Applications
With the switcher completed, several practical scenarios open up:● Home Theater System: Toggle between a media player and gaming console connected to a single HDMI input on a projector or TV.
● Conference Rooms: Quickly switch between two laptops presenting to a projector.
● Gaming Setups: Use one input for a console and another for a streaming PC, with the ability to switch instantly without re-cabling.
● Testing Bench: For developers or reviewers who need to compare two HDMI sources quickly.
Moreover, the presence of OSD adds a polished, professional touch usually reserved for high-end commercial switchers.
Reflections on Working with ADV7622BSTZ
The ADV7622BSTZ is not a beginner component—it’s designed for commercial-grade equipment. However, for advanced DIYers looking to build something substantial and unique, it offers a rich set of features that can be harnessed with patience and planning.The key challenges lie in:
● Power supply design, especially with multiple voltages.
● Managing HDCP (High-bandwidth Digital Content Protection) negotiation correctly.
● Handling high-speed HDMI signal integrity during board layout.
But these challenges also make the project deeply rewarding. You’re not just building a gadget—you’re gaining insight into the same technology that powers professional AV gear.
Potential Upgrades and Expansion Ideas
Now that a working prototype is done, you can imagine future iterations with expanded features:● Add an IR receiver to control input switching via remote.
● Integrate an OLED or small TFT display to show input names externally.
● Expand the switcher to support four or more inputs using external multiplexers.
● Incorporate an audio extractor for sending sound to a separate amplifier.
● Add USB power support for portability.
The ADV7622 is capable of much more than just switching—it supports advanced audio formats, consumer electronics control (CEC), and more. There’s room to explore.
Conclusion
This DIY HDMI switcher project centered around the ADV7622BSTZ is a perfect example of how high-end electronic components can empower enthusiasts to create real-world, useful devices. By focusing on a clear, functional goal—switching between two HDMI sources with OSD feedback—we built something practical and refined.This isn’t just another blinking LED or basic sensor circuit—it’s a deep dive into the world of high-speed digital video, a realm often considered out of reach for hobbyists. But with components like the ADV7622BSTZ and careful planning, even HDMI video becomes accessible for DIY creation.
And the best part? Every time you switch sources and see that crisp OSD confirmation, you’re reminded that it’s not some off-the-shelf box doing the work—it’s something you built with your own hands.
US 13623 
GB 11707 
CA 9499 
AU 8453 
IE 5891 
BR 4087 
NZ 2018 
SG 1046 
