So we have a two chip board: * STM32 running NuttX (v7.5 I believe) * ESP32 acting as a coprocessor running custom firmware
The STM32 runs the show and the ESP32 provides services to the STM32 code. In normal run mode, NuttX has a kernel thread that reads data from the ESP32 over UART (/dev/ttyS2) and then processes the data. This is working fine as is. The UART is configured to use a 512 byte buffer. Every now and then we want to upload new firmware to the ESP32. This is done by a user mode thread and it goes through the following steps: * Signals to the kernel thread that it should close the UART and exit. * Opens the serial port * Starts the programming sequence If we try to do this then the user mode thread misses bytes in the byte stream. Kernel mode thread only: When the system starts then this thread works fine, no bytes are lost. User mode thread only: If we do not start the kernel mode thread then the programming works fine, no bytes are lost. Both threads: Starting the kernel works fine, we do not miss any bytes. The kernel thread can be stopped, the UART is closed correctly. The user thread can open the serial port correctly after the kernel thread has stopped but now it misses bytes. So we know the individual threads work as expected when used on their own but not together. How anyone seen this or have any advice on how we can resolve the issue? Regards, Mark ______________________________ mark.stev...@wildernesslabs.co
