Help needed to choose right rotary display interface for project

[MCH]

Hello all,

I am not sure ASR is the ideal forum to post this one, but there are a lot of people here with background in electronics and maybe they can point me to the right place if this is regarded too much off topic. The final application is an audio system though, so not 100% disconnected…

I have recently completed successfully a project I had to build a wireless remote volume and tone control knob.

Building a wireless remote volume control with a rotary knob for Raspberry pi - help needed with Python

Hello team, I have been exploring the possibility to diy a remote volume control in the form of a volume knob for some time. Unfortunately such a thing is relatively rare, and the ones that exist don't really fit my system. Not surprisingly, I am not the only one interested, and there is even a...

www.audiosciencereview.com

Thanks to the help of a few members here, the project ended up being faster and cheaper than I initially thought. This means I will have some time and resources to go a bit beyond that for a more ambitious one. One thing I learned building and using the knob is how much better is for audio applications a rotary encoder vs push button interface. You grab the thing and turn it to the desired level without having to look at it, I really like using it, to the point that my other regular IR remote has been sitting on a corner doing nothing since I have the knob.

With this new project, I want to build a more complete interface to control the same system. It should have a small display to navigate through the different functions and a rotary encoder to change the values. It should be remote but this time I don’t aim it to be wireless because it will probably need too much energy to light the display. I am thinking of connecting the knob/display to an Arduino/raspberry pico/raspberry pi and from there connect to the raspberry pi running camilladsp that controls my audio system.

There aren’t many devices that fulfill my needs, so far I have only found these two (the aliexpress links contain videos that show how they operate, they are super cool!):

The first one is from the company DWIN:

https://www.dwin-global.com/dwin-1-54-inch-circular-rotary-screen-dmg24240c015_13wn-product/

https://fr.aliexpress.com/item/1005004860952623.html?gatewayAdapt=glo2fra

PROS:

• It can be ordered as single unit and is cheap
• It is well documented. In DWIN website you can find their software that you can use to create the menus and they even have video tutorials. You just create what you need with the software, flash the result to a SD card and flash from the SD card to the knob with an adaptor they also sell
• Once set up, it can communicate with an Arduino via serial and I even found some tutorials on how to do it (for a different display though). Seems that you don’t even need any library to get the communication working:

https://how2electronics.com/interfacing-dwin-hmi-tft-lcd-display-with-arduino/

• Seems that there is a serial /python library that would help to close the loop and communicate with my raspberry/camilladsp through pycamilladsp library (I hope I am not wrong here, advice is welcome):
  • https://pypi.org/project/pyserial/

CONS:

• The display is not the prettiest and seems quite small. I have the feeling it will give the setup a retro look that is not my preference…
• The form factor is not ideal. These knobs are designed to be inserted in appliances and the depth is quite big, 4 cm. It is not a deal breaker but I would prefer something more flat that can sit alone as a movable control

The second one if from the company TSD and looks much better!:

https://www.alibaba.com/product-detail/1-3-Inch-240-240-Resolution_1600522854726.html

https://www.tslcd.com/1-3-inch-uart...e-hmi-knob-tft-lcd-display-solution_p677.html

PROS:

• The looks, the display seems much crispier and modern
• The form factor is exactly what I am looking for
• Can be ordered as a single unit sample from alibaba

CONS:

• It has a “UART/USB” connection, but on the contrary to the DWIN, I don’t see that TSD has any public application to design the menus, and I have not found any example of how to make it communicate with a computer or a microcontroller. If you know something, i would be very interested to hear it.

Guys, what do you think? If you think there is a chance to make the second option work, I would definitely go for it, but I have no idea where to start my research, any clue or advice will be much appreciated. If you know the technology and you think that an absolute noob like me has no chance to make this work, I will appreciate that too before wasting much time.
Regarding the first option, do you think it is as “easy” as it seems or am I missing something?
More generally, do you know something else equivalent, well documented and that doesn’t break the bank? (yes, the 200 euros google thermostat breaks the bank…)
Thanks!

 

[staticV3]

Here's another one of these with a rotary dial and much higher screen resolution (480x480): https://www.aliexpress.com/item/3256804935405680.html

I found it via this YouTube video: link

 

[MCH]

Here's another one of these with a rotary dial and much higher screen resolution (480x480): https://www.aliexpress.com/item/3256804935405680.html

I found it via this YouTube video: link

this one makes the others look like toys! and with a ESP32 module included!!
the official website only has the documentation in chinese... will see what else i can find. Thank you for this @staticV3

 

[MCH]

A different layout and definitely not my cup of tea, but based on the same esp32-s3, and with a battery.
The functionality shown in the video is pretty much what i am aiming for, and seems to work smoothly.

The same lilygo sell a round display very very similar -i bet it is the same- to the one in the knob above.

 

[staticV3]

another find in my recommendations:

 

[MCH]

another find in my recommendations:

Yes, that one seems like the Cadillac of knobs, but it costs a little fortune to build and some of the key parts are unobtainable as of today. But seems that there is a community trying to make it possible, so who knows, maybe one day one can just buy it

 

[restorer-john]

Here's another one of these with a rotary dial and much higher screen resolution (480x480): https://www.aliexpress.com/item/3256804935405680.html

I found it via this YouTube video: link

That looks like a very interesting little product. Thanks for posting.