[BK7231N/CBU] Modemix MOD001 WiFi Tuya shutter controller

Today we are programming a device that is confusingly similar to the previously discussed MOD003 double relay and differs only in the software and markings on the housing. Even inside the PCBs are identical. The aforementioned MOD003 had two relays and supported the connection of two buttons, but it simply controlled the light - the product from this topic is something else, it is a roller shutter controller, i.e. you can connect two astable buttons (one to move the roller shutter up, the other down) and two relays from the inside control the motor in such a way that they are never both activated at the same time and the shutter opening/closing time is controlled and limited by the application. The Tuya application supports the calibration of roller shutters and you can set the opening / closing time, which should be selected individually after installing the controller, but here I will focus only on showing its interior and changing the firmware.

By the way, it's worth learning about related topics. About MOD003:
https://www.elektroda.pl/rtvforum/topic3976806.html#20572374
General topic about the configuration of blinds in OBK (not mine, work by one of our users):
https://www.elektroda.pl/rtvforum/topic3972935.html
The firmware repository that we will upload to this product to free it from the cloud:
https://github.com/openshwprojects/OpenBK7231T_App
Its documentation:
https://github.com/openshwprojects/OpenBK7231T_App/blob/main/docs/README.md
UART programmer:
https://github.com/openshwprojects/BK7231GUIFlashTool

Buying a controller
The product costs about PLN 75 in Polish online stores. It is sold by various sellers, here I describe the art available under the Modemix logo.

The product was given to me by a reader so that I could change the firmware for him, thank you for sharing the equipment for the topic. After the change, the product returns to the reader.
This is how it looks in the application:

Dimensions:

And assembly:



The roller shutter is controlled by switching on either L1 (movement up) or L2 (movement down). This is done by pressing the S1 or S2 buttons. The firmware does the rest. There are no hardware sensors to check if the blind is fully opened, etc. In the Tuya application, you can only calibrate the blinds by specifying the working time needed to fully open and close the blinds.

Kit Contents
What do we get for PLN 75?

This time they didn't even give mounting screws, which is a pity.

The interior of MOD001
We pry the cover and remove the hooks, then you can remove the PCB:

The PCB comes out pretty hard. The WiFi CBU module with BK7231N is on an additional board, on it there is also a diode indicating the WiFi status and a pairing button.

For the rest... it's a 1:1 module MOD003 , only with different firmware. PCB is the same.

If in doubt, please refer to the topic MOD003 .

Bottom of the PCB:

You can see AMS 1117 3.3V - LDO regulator, and the system on which the power converter is made - KP15051SP.


MOD001 programming
Identically as in the case of MOD003, we only solder RX, TX, ground and 3.3V:

In practice it looks like this:

It's just that in the photo I used a yellow cable for ground, and a brown one for power.
Here is the whole system, with 3.3V power supply from the LDO:

We flash this:
https://github.com/openshwprojects/BK7231GUIFlashTool
The procedure is simple:
1. disconnect the power supply from the module
2. Connect the USB to UART converter to the PCB
3. start the backup and write process in BK7231GUIFlashTool, then waiting for the "getting bus" will start
4. connect this power supply to the module
5. then the module programming will start
By the way, it is worth giving a list of his departures once again:
- P7 - WiFi LED
- P8 - pairing button
- P9 - relay 1
- P17 - relay 2
- P24 - button 1
- P26 - button 2
OBK template:


Summary
This was a description of changing the firmware of the MOD001 Modemix roller shutter controller. However, it did not contain a description of its configuration, because at the moment I do not have a blind for it, and I changed the firmware for one of the readers. After all, I think that the control of roller shutters will be explained soon - OpenBeken contains a scripting system that is so advanced thatThat interlock relays can be implemented without editing the code, as well as detailed timers for opening/closing roller shutters. Details soon, for now that's it, the most important thing is done - the module is freed from the cloud, now you can have fun.
The firmware change went without any problems, and it is obvious that there are basically no differences between the two-channel smart switch (controlling two lights through two receivers) and the roller shutter controller. Hardware is the same. Only the software differs (e.g. in the roller shutter controller, it makes sure that both relays are not switched on at the same time).
NOTE: In the meantime, more or less during the work on this topic, one of the OBK users himself described the configurations of roller shutters in this system (in conjunction with Home Assistant). Therefore, I recommend you to read the topic below:
https://www.elektroda.pl/rtvforum/topic3972935.html