Arduino for STM32

think the rx buffer can not hold GPG messages, when the data exceeds 64 characters, exceeded data will lost. You can try code:
String input = Serial1.readStringUntil('\n');

Dear fpiSTM

I read the information you mentioned, I use the Arduino IDE to program the MCU. When I put the file build_opt.h under the project sketch, the compile give the error, say no build_opt.h file. I use a AI assistant and save the file at the 'stm32duno'\libraries\STMCore. It works. But the ...

I am using Arduino IDE to program the STM32F103C8T6. It works. But I can not change the Rx and Tx Buffer size for Seiral1. I know the HardwareSerial.h have the following #defines as:
// NOTE: a "power of 2" buffer size is recommended to dramatically
// optimize all the modulo operations for ring ...

I want to have timer, the resolution of the timer should be 0.1μs. Can I get such timer in arduino enviroment!