So you're a Noob? Post your questions here until you graduate! Don't be shy.

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By Mistofeles
Mistofeles wrote:In the mean time, is there a program or script for Linux to make the burning ?
Is the processor OTP or can it be burned many times ?

Answering to my own questions:
- Yes, there is a program ST processors in Linux environment (not tested yet)
- No, it is not OTP, so you can reprogram it 100.000 times
User avatar
By wattage
hkusp wrote:Through brute force and a soldering iron, I got the relay module to work doing this:.

Man, you are a HERO! I've spent a disgraceful amount of time on this £5.80 thing, struggling to get Tasmota firmware on then failing to get anything other than a solid red LED and an occasional blue light on the ESP-1. Was about to crunch both relay and wifi module under my heel in disgust until - after reading at least 50 articles on this - I stumbled onto yours. Surprisingly I had a few 10k resistors lying around and good enough solder skills to attempt the mod so I had a go, although within a few solder joints I was convinced that the board's functioning days were over. Upon completion, I couldn't believe when the relay sparked into life using the Tasmota/Sonoff config window and now I've got the thing wired up and up and running with dyndns!

Thanks so much for this excellent info! :D
User avatar
By Omar Mekkawy
pilol34 wrote:Hello;

I too was very disappointed when buying this module. When I connected it for the first time, it is flashing as shown on this link ( and it was not responding at any of my orders.

After a rechere on the web, I found on the website of the manufacturer ... &p_id=1204
this note:
For this wifi relay module, because there are some counterfeit on other sales platform. So if the LED on-board (D2) are blink constantly (I guess the reason is the STC15F104W have not been programmed), it means the module were not produced in our factory, maybe you need to contact the seller directly. Best regards!

And then I realized that I had to program the module to solve the problem (I not found the original firmware).

Here are the results of my work after several days of work.

ATTENTION, The programming and or the alteration is under your resposability because it is always possible to do an error or mishandling that may endanger the module.

1. An FTDI232 interface is required to connect the USB protector to the module's RX TX pins. Here we use an interface to 5V.

2. Software is required to program the module's STC15F104W. Here I used stc-isp.exe (v6.86E) found on the site (Hey yes, I work under windows).

3. Create a program and compile it in .HEX format. Here I create a .asm program that I compile thanks to the AS31.exe utility from Paul's 8051 Tools at

4.The program must be transferred to the module. It is necessary to think to cross the cables TX RX and one does not branch 5V power supply.

With the programe STC-ISP.exe we load the proramme .hex, we set the clock at 11.0592 MHz, and press the button DOWNLOAD / PROGRAM, Connect the 5V power supply of the module and wait until the transfert is finished.

5. In the COM Helper tab, test the module with commands A0 01 01 A2 and A0 01 00 A1 in HEX-Mode.

6. If the led lights up but the relay does not work, it will alter the module by swapping the resistors R3 and R4. This is probably the most delicate operation you will have to do.

7. Afterwards, follow the setup for the ESP-01 module.

To speed up your work, I give you my version of the program in .HEX format Which will save you from making the item 3. This program is transmitted as-is and without guarantee. I have not done advanced testing and it is not optimized.

I added to the program relay status reading commands.

B0 01 01 B2 -> Reading relay in text format ("ON" and "OFF" ending with a linefeed).
B0 01 00 B1 -> Relay reading in binary format (00 = ON and 01 = OFF).

B0 00 01 B1 -> Reading the firmware version in text format ending with a linefeed.

You just have to copy and paste into a text file with the extension .hex.

File: LcWifiRelayUartV1_0_9600_11mhz.hex

Code: Select all:0300000002017387

Now it's up to you to do the rest.

Good luck.

I got the board and it was blinking by itself ( without the ESP8266 ). After applying your steps I got updated its firmware and the microcontroller itself is working properly using the serial commands. Thank you a lot for your help. This firmware works properly for the blinking issue.