About this service
HandShake is a free, open-source configuration and firmware service for the Lilygo T-Watch S3 and T-Embed. It lets you generate and flash device firmware that turns these devices into components of an AAC (Augmentative and Alternative Communication) switch interface.
We do not sell, modify, or supply hardware. Devices are purchased directly from Lilygo and arrive as unmodified, manufacturer-certified products (CE/FCC). This site provides configuration and firmware only.
No warranty
This software is provided “as is”, without warranty of any kind, express or implied, including but not limited to warranties of merchantability, fitness for a particular purpose, and non-infringement. In no event shall the authors or contributors be liable for any claim, damages, or other liability arising from, out of, or in connection with the software or its use.
Important safety note
HandShake-configured devices may be used to support access to communication for people who rely on AAC. Because of this, we strongly recommend:
- Initial setup and switch-function testing is carried out or supervised by a relevant professional (occupational therapist, speech and language therapist, or experienced carer).
- Switch response is verified — confirming reliable activation and no false triggers — before any unsupervised or high-stakes use.
- The firmware version identifier is noted for each deployed device, so any issue can be traced to a specific build.
- Faults or unexpected behaviour are reported promptly using the link below, and the affected device is taken out of use until resolved.
This tool is provided in good faith to support AAC access, but it is not a certified medical device, and responsibility for confirming a device’s suitability for an individual’s needs rests with the person or professional deploying it.
Reporting issues
Found a bug, or had a device behave unexpectedly? Please contact matt@mattoppenheim.com. Include a description of what happened — this helps us fix it and warn other users if needed.
License
HandShake firmware is licensed under AGPLv3. This configuration website’s source will be made available once it’s fully functional and tested at https://gitlab.com/mattoppenheim/handshake/handshake_website