SFP-to-TTL v1.2 Adapter

SFP-to-TTL adapter v1.2 (top & bottom)
SFP-to-TTL adapter v1.2 (top & bottom)
💡
From Jan 16th 2026, all boards shipped are v1.2.

Breaks out a GPON stick’s 20 pins so you can flash firmware using a serial adapter. No soldering required 👍

💶 Price: €20
✈️ Ships worldwide
🧭 Always ships with tracking number.

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Description

The SFP-to-TTL v1.2 is a compact adapter that exposes the 20 pins of a GPON SFP module connector to make the 3V UART lines (TX, RX, VCC, GND) accessible. Perfect for:

  • flashing OpenWrt / Carlito / stock firmware
  • debugging the bootloader
  • grabbing serial logs without fiddly pogo-pins

Key features

Feature Detail
Version v1.2 (white)
Exposed pins 2x20 SFP connector pins (UART, I²C, GPIO, etc.),
Silkscreen RX⇆TX and TX⇆RX clearly labeled
SFP connector High-quality Molex® SFP slot, direct module insertion
What's new from v1.1
  • Includes 2 capacitors to improve compatibility with cheap USB-TTL adapters without using an external power supply (hopefully)
  • Adds ground area
  • Increased VCC line width
  • Respects SFP pins numbering
  • Inscreased marking lisibility
Power 3.3V via VCC pin (from FTDI or external source)
Dimensions 41.25 mm × 22.5 mm

FAQ

How do I order?

  1. Click here to provide your informations (email/country/zipcode)
  2. An email will be sent with a quotation depending on your location and payment link will be included.
  3. Once payment received, the item will be shipped and a tracking number provided. Usually ships the next working day.

How much is shipping/handling?

Each board is carefully packed using foam and bubble wrap, then shipped in a envelope.

For shipping, I rely on official French Post rates. I don’t add any margin on shipping costs, and all shipments include a tracking number. Better for you, better for me 🙂

2026 shipping & handling rates:

  • France: 4€
  • EU / US / UK / Switzerland: 6€
  • Other countries: on request (most of the time equals to EU pricing but to be confirmed)

Will it work with my module?

The adapter exposes all 20 standard SFP pins, so in most cases, yes, it should work.

Below is a community-driven list of SFP / SFP+ / ONU modules that have been successfully accessed or flashed using the SFP-to-TTL adapter.
This list is based on real user feedback, not theoretical compatibility, and obviously not exhaustive.

Brand Model Status
Huawei MA5671A ✅
FS.com GPON-ONU-34-20BI ✅
FS.com XGS-ONU-25-20NI ✅

What else do I need?

  • A USB-TTL 3.3V adapter and 4 female-female Dupont cables
  • A USB cable for your computer
  • A compatible SFP/ONU GPON module (FS.COM, Huawei MA5671A, etc...)
  • A serial console app (screen, PuTTY, minicom, ...)

My module keeps rebooting

There's an article about this.
TL;DR, it's likely a serial adapter (USB-TTL) power supply issue.

Version 1.1 relies 100% on the quality of your USB-TTL adapter.
Version 1.2 adds 2 capacitors to help preventing this issue.

Return Policy

I'm a small-batch maker and every adapter is carefully assembled and individually tested before shipping to guarantee it works as expected.

Because of the nature of this product and the fact that it’s intended for developers, I unfortunately cannot accept returns, exchanges, or refunds.

If you have any questions before ordering or need help using the adapter, feel free to reach out, I'm happy to assist you and make sure you get the right product for your needs.

Thank you for your understanding and support 🙏

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