HowTo: Tasmota – Flash Tasmota firmware to Sonoff iFan03 module

There are some practical modules in the Sonoff range. This also includes the "Sonoff iFan03". This is actually intended to be able to control ceiling fans and a connected lamp via remote control and WLAN.

Like many other Sonoff modules, the iFan03 module can also be equipped with the free Tasmota firmware.

How you can program the Tasmota – or other firmware – on the iFan03 is described in the following article.

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.

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Helpful Articles:
Before you start with this article, it makes sense to read the following articles.

Tasmota-Flash firmware
ESP8266 – flash .bin files in Windows with the “Esptool”

Required tools:

Required material:

Prepare the Sonoff iFan03 module for the flash process

In addition to the actual module, the scope of delivery of the Sonoff iFan03 also includes a 433MHz radio remote control which can be used to control the connected fan. Up to three speed levels can be set.

In addition, a small additional consumer, such as a lamp, can be switched on and off.

View of the components belonging to the Sonoff iFan03.

Another view.

In order for the module to be programmed, you must first open the housing and remove the circuit board.

On the module you can see at the bottom …

… a connector for six contacts.

There is a label on the back of the board...

… that assignes a function to each pin.

The interesting pins are the three pins "VCC", "RX", "TX" and "GND". The module can be programmed with an alternative firmware via these pins.

Programming is easiest if you first solder on a four-pole pin header.

To do this, plug the pin header into the contacts as shown and …

… solder it to the board with some solder.

When soldered, it should look like the picture.

Connect the USB to serial converter

For the actual programming process, you now have to connect a USB serial converter.

So that the USB-serial converter can communicate with the Sonoff module, you now have to make a few connections.

Four Dupont cables are best for this.

With these you have to connect the module and the USB serial converter according to the following pattern.

Sonoff moduleUSB to serial convertercolour

View of the connected Dupont cables on the USB-serial converter.

View of the connected Dupont cables on the Sonoff module.

Another view of the Sonoff module with the connected USB-serial converter.

Perform the flash process

The actual flash process is described in the article Tasmota-Flash firmware.

If you want to flash a precompiled .bin file, you can also refer to the article ESP8266 – with the “Esptool” flashing .bin files under Windows.

Important: In order for your Sonoff module to switch to programming mode, you have to hold down the white button while you plug the USB-to-serial converter into the computer. then hold the button down for another three seconds and then release it. Then you can start with the programming process.

Set the appropriate template

As soon as you have flashed the Tasmota firmware onto the module, you still have to configure the firmware as Sonoff iFan03. The template below is suitable for this.


You can enter this template in the Tasmota interface under "Configuration" -> "Configure other". This should automatically configure the corresponding outputs and inputs on your iFan03.

Additional information

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. 🙂

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    1. Hey Scriper,
      Yes and no. Of course, the TX of the transmitter must be connected to the RX of the receiver. Unfortunately, the labels are not always clear. Sometimes the manufacturers also mark which pin of the remote station has to be connected.
      But the good thing is that mismatching doesn't destroy anything. The only thing that doesn't work then, of course, is communication.
      If in doubt, simply exchange RX for TX (or vice versa). 🙂
      Best regards

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