[RTduino][stm32g474-nucleo] update readme

bsp/stm32/stm32g474-st-nucleo/applications/arduino_pinout/README.md

@@ -53,6 +53,10 @@ For additional information on pin layout, refer to [pins_arduino.c](pins_arduino
 | 23 (A6) | -- |  | On-chip reference voltage ADC, default controlled by RT-Thread's ADC device framework adc1 |
 | 24 (A7) | -- |  | On-chip temperature sensor ADC, default controlled by RT-Thread's ADC device framework adc1 |
 
+> Notice:
+> 
+> 1. Don't use a same hardware timer to drive PWM (analogRead) and servos at same time, because hardware timers can only generate a same frequency for 4 PWM channels. Otherwise, it could cause a failure when drive servos.
+
 > References:
-> 1.[stm32-nucleo-64-boards-mb1136-stmicroelectronics.pdf](https://www.st.com/resource/en/user_manual/dm00105823-stm32-nucleo-64-boards-mb1136-stmicroelectronics.pdf)
-> 2.[ST-Nucleo-G474RE](https://os.mbed.com/platforms/ST-Nucleo-G474RE)
+> 1. [stm32-nucleo-64-boards-mb1136-stmicroelectronics.pdf](https://www.st.com/resource/en/user_manual/dm00105823-stm32-nucleo-64-boards-mb1136-stmicroelectronics.pdf)
+> 2. [ST-Nucleo-G474RE](https://os.mbed.com/platforms/ST-Nucleo-G474RE)

bsp/stm32/stm32g474-st-nucleo/applications/arduino_pinout/README_zh.md

@@ -54,6 +54,10 @@ Hardware Drivers Config --->
 | 23 (A6) | -- |  | 芯片内部参考电压 ADC，默认被RT-Thread的ADC设备框架adc1接管 |
 | 24 (A7) | -- |  | 芯片内部温度 ADC，默认被RT-Thread的ADC设备框架adc1接管 |
 
-> References:
-> 1.[stm32-nucleo-64-boards-mb1136-stmicroelectronics.pdf](https://www.st.com/resource/en/user_manual/dm00105823-stm32-nucleo-64-boards-mb1136-stmicroelectronics.pdf)
-> 2.[ST-Nucleo-G474RE](https://os.mbed.com/platforms/ST-Nucleo-G474RE)
+> 注意：
+> 
+> 1. 驱动舵机和analogWrite函数要选择不同定时器发生的PWM信号引脚，由于STM32的定时器4个通道需要保持相同的频率，如果采用相同的定时器发生的PWM分别驱动舵机和analogWrite，可能会导致舵机失效。
+
+> 参考资料:
+> 1. [stm32-nucleo-64-boards-mb1136-stmicroelectronics.pdf](https://www.st.com/resource/en/user_manual/dm00105823-stm32-nucleo-64-boards-mb1136-stmicroelectronics.pdf)
+> 2. [ST-Nucleo-G474RE](https://os.mbed.com/platforms/ST-Nucleo-G474RE)