Hardware Itead Sonoff RF Bridge

Itead Sonoff RF Bridge

Property	Value
Manufacturer	Itead Studio
Product page	https://www.itead.cc/sonoff-rf-bridge-433.html
Wiki page	https://www.itead.cc/wiki/Sonoff_RF_Bridge_433
Build flag	ITEAD_SONOFF_RFBRIDGE

Introduction

Here is the original post on sonoff rf bridge:
https://tinkerman.cat/hacking-sonoff-rf-bridge-433

Please note that flashing ESPurna alone, while giving you most of the features you would expect from this firmware, cannot widen the range of RC remotes that the Sonoff RF Bridge can recognize. On this device the RF decoding is not performed by the main processor running ESPurna. Instead, the task is performed on an auxiliary microcontroller, an EFM8BB1, which has its own firmware dedicated to this job.

Currently, there are two ways to overcome this limitation and they are listed below in the section Modifications.

Modifications

ESPurna supports two hacked variants of the Sonoff RFBridge:

• Custom EFM8BB1 firmware by @Portisch, which replaces the original SONOFF one.
  Key points:
  • More protocols supported out of the box
  • New IN and OUT message format known as RAW, allowing ad-hoc protocol development
  • Types of hardware recognized: check on RF-Bridge-EFM8BB1 project page
  • Can beep on demand
  • No need to solder or cut traces on the board
  • but..., You would need an Arduino or something alike to program the auxiliary controller using C2 debug interface
• RFB_DIRECT bypasses the EFM8BB1 entirely and lets ESPurna handle the encoding/decoding. Key points:
  • Fully integrated in ESPurna.
  • Types of hardware recognized: anything recognized by the rc-switch library (fork).
  • You must cut traces on the Sonoff board and correctly solder RF transmitter and receiver pins

Flashing

Flashing esp8285:

• disconnect the sonoff-rf-bridge from all power sources
• move the switch towards off position (towards the 5pin serial connector)
• press and hold the button on the side
• connect serial cable (gnd, rx, tx, 3v3)
• flash firmware

Known issues

Most recent RF Bridge revisions are not (currently?) supported by the custom EFM8BB1 firmware

• https://github.com/xoseperez/espurna/issues/2526
• https://github.com/arendst/Tasmota/discussions/13283