HowTo: Tasmota – Sonoff RF Bridge RF chip (EFM8BB1) flashing with Portisch firmware

Thanks to the very universal Tasmota firmware (see: flashing Sonoff 433Mhz Rf Bridge with Tasmota firmware), you can use the Sonoff RF Bridge to send and receive just about any 433Mhz signal. However, this works only for 433Mhz signals whose radio protocol is detected by the firmware of the EFM8BB1 processor. That means you receive - with the standard firmware - only radio data already interpreted by the EFM8BB1 processor. Thanks to a firmware update, you have the option to read out any wireless raw data.

Which modifications you have to make and what you have to pay attention to is described in this article.

Hints for our lovely english readers: Basically, many of the articles on Nerdiy.de are translations from the original german articles. Therefore, it may happen here and there that some illustrations are not available in english and that some translations are weird/strange/full of mistakes or generally totaly wrong. So if you find some obvious (or also not obvious) mistakes don't hesitate to leave us a hint about that in the comment section. 
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Safety instructions

I know the following hints are always a bit annoying and seem unnecessary. But unfortunately, many people who knew it "better" from carelessness lost their eyes, fingers or other things or hurt themselves. In comparison, a loss of data is almost not worth mentioning, but even these can be really annoying. Therefore, please take five minutes to read the safety instructions. Even the coolest project is worth no injury or other annoyance. https://www.nerdiy.de/en/sicherheitshinweise/

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Requirements

Helpful Articles:
Before you start building, you should have dealt with the soldering basics. You have to solder wires to contacts. In addition, you should have already flashed your Sonoff RF Bridge with the Tasmota firmware.
The following articles contain information about this:
Electronics—My friend the soldering iron
Sonoff – 433Mhz RF Bridge flashing Tasmota firmware
Basics of navigation in Windows Explorer

Required tools:

In the following list you will find all the tools you need to implement this article.

Required material:

In the following list you will find all the parts you need to implement this article.

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Disconnecting unnecessary data lines

The data lines of the EFM8BB1 (RF chip) that you need to connect during this mod with the ESP8266, are standard connected to the data lines of the micro USB port that normally powers the RF bridge.

Probably the manufacturer has a special adapter which allows him to program the EFM8BB1 in this way – for us this function is useless and in this case even a barrier on our way of flashing the EFM8BB1. In conclusion this means that you can not power the RF bridge via the micro USB port at the same time and program the EFM8BB1.

To make this possible anyway, this section explains how to cut through the connections from the EFM8BB1 to the micro USB port.

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Connecting the data lines of the EFM8BB1 to the ESP8266

In order to connect the needed GPIOs of the ESP8266 with the data lines of the EFM8BB1, you first have to prepare two cables about 3 cm long.

Before starting up, you should now follow the tips from the article Electronics—Commissioning a new circuit.

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Preparing the Tasmota firmware

For the Tasmota firmware to be able to flash the EFM8BB1, you need to enable the following option in the Tasmota firmware.

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Upload the new firmware to the EFM8BB1

With the modified hardware you can now easily change the firmware of the EFM8BB1 from the usual Tasmota configuration page of the RF-Bridge.

The new firmware then behaves first like the old firmware. The difference is that the new firmware can also be switched to a raw mode.

What this is all about and how to use it will be explained in another article.

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Have fun with the project

I hope everything worked as described. If not or you have any other questions or suggestions, please let me know in the comments. Also, ideas for new projects are always welcome. 🙂

P.S. Many of these projects - especially the hardware projects - cost a lot of time and money. Of course I do this because I enjoy it, but if you appreciate that I share this information with you, I would be happy about a small donation to the coffee box. 🙂