Building a VFO controller using Si5351 and ESP32 for my IC-718, following the W8TEE design from Arduino Projects for Ham Radio. Got the frequency generation working perfectly, but struggling with implementing proper CAT control over serial. The ESP32 serial handling seems different from standard Arduino - anyone successfully integrated CAT commands with Si5351?

Planning to add band decoder outputs and memory channels next. Current setup: ESP32 DevKit, Si5351a breakout, 2x16 LCD with I2C backpack.

I've done exactly this project! The ESP32 has multiple hardware serial ports - try using Serial2 for CAT while keeping Serial for debugging. Also check your baud rate settings, the IC-718 can be picky about timing.

Watch out for the Si5351 I2C address conflicts if you're planning to add the LCD on the same bus. Some breakout boards use different addresses than expected. Post your current CAT parsing code - happy to take a look.

Are you implementing Kenwood TS-480 emulation for the IC-718 CAT interface? That's usually the most compatible approach. The ESP32 Arduino core has some quirks with serial buffer handling compared to ATmega chips.