[SOLVED] Sonoff RF Bridge 433 mhz (newer version) Flash with Tasmota

Has anyone managed to successfully flash Tasmota onto the newer version on the Sonoff RF Bridge. This Sonoff is the one with 2 “squared” edges on the casing as per the below link


All the examples I can find online have a switch on the board and more obvious pin locations, which this nodel does not have. It also looked like these might be flashable via the onboard USB connection but I have been unsuccessful with attempting this. If anyonw has any guides/links/info for flashing this model that would be massivly helpful.

For info: I am using Arduino on Mac to flash my devices and have successfully flashed several Sonoff Basics, T1’s 1,2 and 3 gang, and TH16’s but this one is so far beating me!

I have flashed this one ( without soldering, just holding the pins into the holes while flashing)…
I can connect to it via WLAsN and MQTT, however the RF part isn’t recieving anything.

Maybe better try to get answers in https://github.com/arendst/Sonoff-Tasmota

A newbie question, is it even legal to modify firmware on sonof devices and gateway? They could sue the community for destroying their business somehow. We need to be careful about distributing firmware hacks on this community. @Kai I hope we have good relations with Sonof. Otherwise, I am afraid this will get us into trouble someday.

Don’t believe there’s a legal problem in EU or US. The difficult cases are where you’re modding to circumvent copyright protection, but this obviously isn’t that.

I managed to successfully flash the Sonoff Bridge. The newer ones (or at least the version I have) have the LED “pad” above the switch that is mentioned in other threads so you just need to use a small tool to get under the LED and flick the switch to the off position for flashing. The switch hiding under the LED is not immediately obvious!

place the switch in the off position, and hold down the pairing button while you connect your FTDI adapter to get into flashing mode.

There seems to be very little documentation on these which is a little
surprising as the Sonoff hardware is a popular choice due to the cost (or lack of).

Since flashing the unit, there are a few options on the Tasmota interface which I have no idea how to use (Again, not much documentation out there!) but once the unit is flashed and connected to your MQTT broker. you can see the device ID which has been triggered in the JSON response. simply use the JSONPath transformation to interrogate this and determine which device has been triggered. The rules I have used for this are below.

the MQTT broker recieves the following JSON string from a triggered device.

.items file

String  RF_BRIDGE "RF Bridge"	{mqtt="<[broker:tele/sonoff_RF_001/RESULT:state:JSONPATH($.RfReceived.Data)"}

The JSONPath will extract the 38AE99 from the Triggered event. Because you will receive a JSON response to the RF_BRIDGE item for every device in range which triggers, you will need to use this ID to determine which of your devices triggered. If you use MQTTfx all you need to do is subscribe to the relevant topic and connect/disconnect your sensors. Note that the sensors do NOT need to be paired to the RF Bridge.

.rules file

rule "RF Bridge sensor triggered"
    Item RF_BRIDGE received update
    if(RF_BRIDGE.state == '38AE99')
        //Front door was opened
        //Perform relevant tasks
    if(RF_BRIDGE.state == '349DA4')
        //Back door was opened
        //Perform relevant tasks

You should probably consider using a switch statement rather than IF’s but you get the idea…

Information about Tasmota: https://github.com/arendst/Sonoff-Tasmota/wiki (very little… only 113 pages… :wink: ) e.g. supported commands… https://github.com/arendst/Sonoff-Tasmota/wiki/Commands and the RF Bridge… https://github.com/arendst/Sonoff-Tasmota/wiki/Sonoff-RF-Bridge-433 with some additional links… :wink:

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Some help in video: https://www.youtube.com/watch?v=OfSbIFIJPuc&t=207s

Not only is it legal but itead actually documents the pcbs and way to flash new firmware on it.

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I went through different topics on this forum and decided to put all together. I wrote a flashing Tasmota post here if somebody needs tutorial step by step how to configure Sonoff Bridge with OpenHAB with no rules if you control only.


Thanks for your work !