KunYi Chen

0x55 & 0xAA 應該是 01010101 & 10101010 因為那個年代硬體不可靠 選的可以比較容易檢驗出來硬體問題 XD 不能因為是讀Linux source code 而忽略IBM PC 誕生時的狀況 這也是那個年代BIOS 開機要做POST 很多硬體檢測的原因 現代UEFI 都不做這些檢測只做硬件初始化了

0x7C00, https://zhuanlan.zhihu.com/p/38433204 可以參考這篇

maybe need check "include_dir" in your mosquitto.conf to add /etc/mosquitto/conf.d directory please ref. https://mosquitto.org/man/mosquitto-conf-5.html and check "" for add your conf.d folder I testing on Chirpstack Gateway OS v3.3.2 is...

@RAKWireless , thank your for you reply but about question 2. in STM32L0 HAL have [HAL_RS485Ex_Init](https://github.com/STMicroelectronics/STM32CubeL0/blob/904c92833dc000c5819504d230c29e882d18f691/Drivers/STM32L0xx_HAL_Driver/Src/stm32l0xx_hal_uart_ex.c#L133) function for RS485-DE How to apply the functions in RUI SDK?

okay, maybe some information missed, please check your RAK4200 user manual about UART1-DE and UART2-DE (DE: Driver Enable) and check your RUI SDK/STM32L0Cube about [HAL_RS485Ex_Init()](https://github.com/STMicroelectronics/STM32CubeL0/blob/904c92833dc000c5819504d230c29e882d18f691/Drivers/STM32L0xx_HAL_Driver/Src/stm32l0xx_hal_uart_ex.c#L133) I suggestion add a hook...

I knew rtc-board.c implement the below APIs from debug information. maybe you can write down in RUI SDK documents and export header file - RtcInit - RtcGetTimerValue - RtcGetAdjustedTimeoutValue -...

maybe try this https://github.com/helium/longfi-platformio/tree/master/Heltec-CubeCell-Board more detail information ref. https://github.com/helium/longfi-arduino/tree/master/Heltec-CubeCell-Board/helium-mapper

ref. https://github.com/google/ringdroid 只是音頻本身的時域圖不是頻譜

try https://stackoverflow.com/questions/3954852/how-to-complete-a-git-clone-for-a-big-project-on-an-unstable-connection