Yeah, this is a pretty common situation when trying to use external devices like a Topaz signature pad with Power Apps.
What’s happening here is that Power Apps (especially canvas apps) runs inside a browser, and browsers don’t allow direct communication with hardware devices like USB signature pads. So even though the Topaz device works fine with its own SDK, Power Apps can’t talk to it directly.
If your goal is just to capture a signature and show it on the screen, the easiest and most reliable option is to use the Pen Input control. It behaves very similar to a signature pad, works out of the box, and doesn’t require any extra setup.
If you specifically need to use the Topaz device, then you’ll need a middle layer. Typically, this looks like:
- A small app (like a .NET or web app) using the Topaz SDK
- That app captures the signature from the device
- Then sends it to Power Apps (via API, Power Automate, or as an image/base64)
So instead of direct integration, you’re routing it through another application.
There is also the option of building a PCF control, but that’s more suited for model-driven apps and still doesn’t make hardware integration straightforward in canvas apps.
So essentially, Power Apps can’t “see” the Topaz device directly. You either:
- Use Pen Input for a simple and clean solution
- Or build a custom integration layer if the hardware is mandatory
For your current requirement (just capture and display), Pen Input is usually more than enough and saves a lot of effort.
Best regards,
Satyam Pandey
✅ If this helped solve your issue, please mark it as
Accepted Solution so others can find it quickly.
❤️ If it didn’t fully solve it but was still helpful, feel free to click “Yes” on Was this reply helpful? or drop a Like 🙂
🏷️ For follow-ups, feel free to tag @TechFreak
💼 LinkedIn
▶️ YouTube
