This is the most popular method today because these chips output the exact TTL voltage (approx 5V or 3.3V) that the Icom radio expects. You do need a MAX232 chip here. Ff2d V.2.21 - Compromise On The
This was the standard design in the 1990s and 2000s. It converts USB to RS-232 voltages (+/- 12V), and then converts that back down to TTL for the radio. Maid Kyouiku Botsuraku Kizoku Rurikawa Tsubaki
The Icom CI-V system is a serial communication protocol used to control Icom radios. It uses a simple two-wire interface (Data and Ground) that operates at TTL logic levels (5V).
Here are the three most common schematic topologies, ranging from the easiest to build to the most traditional. Best for: Beginners and those who want a reliable, compact build inside a USB cable or small box. Common Chips: FTDI FT232RL, CH340G, CP2102.
Modern computers no longer have serial ports (RS-232), and CI-V is not directly compatible with USB. Therefore, an interface is required to bridge the gap. The schematic design depends entirely on which USB chip you choose to use.