Update on Seeed Studio XIAO ESP32-S3 Plus + W5500 Ethernet Adapter for ESPHome Bluetooth Proxy Use
Hi everyone,
I wanted to provide an update regarding the Seeed Studio XIAO ESP32-S3 Plus used with the XIAO W5500 Ethernet Adapter, particularly for those of you using it (or planning to use it) as an ESPHome Bluetooth proxy.
Several users previously reported instability when using Bluetooth on the Plus model, and Seeed has now confirmed and addressed the issue. Here’s what’s happening and what to expect.
What’s Happening
The Seeed team reviewed the reported issues and confirmed that early batches of the XIAO ESP32-S3 Plus had RF performance problems that affected Bluetooth and Wi-Fi coexistence, especially under higher TX power.
It’s important to note that these boards were originally launched as “Early Build” versions focused primarily on Ethernet connectivity, not specifically for use as active Bluetooth proxies. The Home Assistant community discovered they could be used this way, which helped uncover and highlight these Bluetooth stability issues.
Seeed has since verified and corrected the hardware issue and is proceeding with a two-phase revision plan:
- Phase 1: Remaining early-batch units (around 200 pcs) are being modified with an INT pin wiring fix (D16 → W5500 INTn). These will ship as the current stock.
- Phase 2: A full board revision is planned for early January 2026, which will incorporate all fixes directly on the PCB. A release note will be added on the product page once this new version is ready.
My Test Results
I’ve tested one of the modified units provided by Seeed and can confirm that:
- Ethernet and Bluetooth coexistence are now stable
- Previously problematic Bluetooth devices (like Inkbird sensors) now connect reliably
- Occasional transient
0x3Econnection results may still appear — which is normal behavior for some BLE devices — but reconnections now succeed after one or two attempts
This represents a major improvement over the unmodified early units, which often failed to establish Bluetooth connections at all.
What This Means for You
- If you ordered before November 1, 2025, your board may be part of the early batch and could still show instability when used as an active Bluetooth proxy.
- If you order after November 1, 2025, you’ll receive one of the modified units with the wiring fix applied.
- The fully revised version with integrated fixes is expected in early January 2026.
For passive Bluetooth proxy use (e.g., just receiving BLE advertisements), the older boards generally work fine — just make sure to set the Ethernet polling interval to 1ms in your ESPHome configuration. That adjustment helps maintain consistent packet timing and smooth passive Bluetooth performance even on the early units.
Support and Upgrade Options
Because the early boards were never originally intended for use as active Bluetooth proxies, there isn’t a formal replacement program for existing users.
However, Seeed recognizes that many community members are using these boards for proxy applications and wants to help those who need improved Bluetooth performance.
To support this, Seeed is offering a $10 discount coupon for users who purchased early-batch units (orders before November 1, 2025) and wish to upgrade to the fully revised version once it’s available.
Coupon code: 2VX6LS2P
Valid until: January 30, 2026
If you have questions or run into issues, contact Seeed’s support team directly at [email protected] — they’ll handle individual cases as needed.
Moving Forward
I’ll continue long-term testing with the revised boards under normal proxy loads and share updates as results come in. Once stability is fully confirmed, I’ll also update the “Recommended Boards” list for ESPHome Bluetooth proxies.
Huge thanks to Nickey, Meilily, and the Seeed engineering team for their quick and open collaboration on this. Their transparency and willingness to engage directly with the community have been outstanding — it’s a great example of how feedback and cooperation lead to better products for everyone.