Internet radio Wolna-2. What's inside?

Since December last year, we have been releasing Wolna-2 Internet radios in St. Petersburg. This is the second model in which we have taken into account most of the wishes of users. Who cares what kind of beast - the domestic Internet radio, welcome to the cat!



In this article, I will first describe the main functions, and then walk a little on the internal and key solutions for hardware.



And what is it moget?

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Or maybe it is absolutely what is required of him. That is, play online streams loud and clear. By the way, the receiver is stereo, and in spite of the small stereo base, there is a sensation of surround sound. The built-in equalizer allows you to get a good color for this size. There is a linear output for the external speaker.



Radio stations:







Threads live on two lists: user list, and manufacturer list.



There are about 100 radio stations in the list of manufacturers , and they are constantly being added. You can update them directly through the menu of the receiver. This allows those who do not want to bother with the introduction of streams to find a radio station for themselves.



The second list is user defined. There is already where to roam the real fans of Internet radio. Up to 1000 native streams can be added to the receiver. This is done directly through the receiver menu. You can also do this via a web interface, for example from a smartphone.



Web interface







Recently, we finally implemented a web interface to add stations, and control playback. So far it is simple, but it makes life much easier for those who add a lot of streams, and who are too lazy to get up from the sofa to switch the station. Over time, we plan to turn this feature into a full-fledged control panel.



Built-in battery



The receiver has a built-in 1500 mAh battery. This is element 18650, and it is sealed tightly. Enough for about 3 hours of work at medium volume. If, for example, you use the receiver as a streamer for an external speaker, then there is enough hours for 6, taking into account that the volume of the receiver itself is at its minimum.



What's inside? boom porn







The heart of the hardware was a fresh pebble ESP32. And if you ask me how much I appreciate this microcontroller, then I will say 11 out of 10! This is a bomb! With the cost of a module with a divorced RF part of 250 rubles, they have 2 cores of 240 MHz, 500 to RAM and a 4 MB flash drive. Yes, and built-in wifi and bluetooth. I will definitely write a separate article about him.







The audio decoder is the same - VS1053, it provides excellent sound, while being easy to manage. It has probably become a classic for all microcontroller applications related to mp3.



It was decided to take the finished module with strapping, this allows you to seriously reduce the range of components, as well as save on sealing. The approach was justified, so charging the battery, display and amplifier module is also modular. The result is such a hybrid shawl:







The connectors are plugged into the display with the encoder and amplifier.



Separately, I want to talk about the approach using ready-made modules. We can say that it has become one of the growth drivers, allowing us to optimize production. In a few times reduced:



- Component nomenclature → logistics costs

- work on sealing

- percentage of marriage (apparently they are still checked before sending)



I can write about the software part separately. Again, the microcontroller is very simple to learn, I think many will be interested. For example, it took me about two hours from the first blinking of the LED to connect to WiFi. And the next day, I quietly exchanged data with a TCP server.



At the end, I will attach a small review. Scold, as usual in the comments :) If I hadn’t walked properly in the comments half a year ago, there probably wasn’t any second version, so I am glad with any thoughts!