To control and configure some designs on PIC and ATMEGA microcontrollers, you need to conveniently connect them to a computer or laptop. In a series of microcontrollers PIC16 (on which I usually do my
homemade) there is no hardware implementation of USB, but there is a regular UART serial port, which is a stripped down version of the COM port of older computers. Working with it does not cause any particular difficulties, and also not a lot of resources of the microcontroller are needed, because unlike USB, it has a simpler protocol, which nonetheless allows the same transfer of data. Some computers still have a COM port, although sometimes it is not brought out - in this case, you only need to connect a level converter (for example, MAX232), but on newer motherboards and laptops it is not at all.
In such cases, you can use the UART-USB adapter on the common CH340 chip. On the Aliexpress website, it is usually sold already in the form of a ready-made module on the board, but sometimes it is more convenient to order it separately for permanent use.
In this case, the microcircuit can be soldered directly to your board, and there you can already install the micro-USB jack for convenient cable connection and a more finished type of design.
The connection of the chip is quite simple even for a beginner radio amateur.
For power supply, you need 3.3V (VCC), quartz at 12 MHz (XI and XO pins), the remaining pins are used to work with the COM port (RX and TX are enough to work, the rest are rarely used in order to transmit device readiness signals).
