Adding UART code to the 'light switch server' project

[Paul Mercer]

Hi,

I am evaluating the nRF52840-DK and wanted to add some debug code to the UART.

I have used the same libraries as the 'UART_PCA10056 (which works), but when the code is linked an error comes as follows:-

Please advise where to look at for this error.

[Hung Bui]

Hi Paul, 
It's complaining that the UART0 interrupt handler was defined twice. 
Could you do a full search (Ctrl+Shift+F) and look for "UARTE0_UART0_IRQHandler" ?
Note that in nrf51_to_nrf52.h file we have a define     #define UART0_IRQHandler        UARTE0_UART0_IRQHandler 
So if there is a define of UART0_IRQHandler function somewhere else then we will also have a multiple definition. 

Note that in mesh SDK we also have a serial library called serial_uart.c that you may use. 

[Paul Mercer]

I have done a search and there are 3 instances in the project and all in the same file. I have done a search for other IRQ's and they come back with 3 hits as well.

[Hung Bui]

You can find the usage of the serial_uart.c library in the serial example in mesh SDK. However the use of this module in the example is not for logging but for serialization of mesh stack. 

There must be a define of UARTE0_UART0_IRQHandler inside nrfx_irqs_nrf52832.h if the file was included. 

[Paul Mercer]

Thanks that has sorted that out.

One more question though. I am getting the serial information in the debug window, but want it to come out on the virtual serial port the same as project 'uart_pca10056'. What do I change to make this happen?

[Hung Bui]

You would need to modify the log.c to add log callback for uart instead of rtt. Then modify main.c to call __LOG_INIT with the callback to uart. 

[Paul Mercer]

Can you please give an example of this, even if it is text and not an actual example.

[Hung Bui]

Hi Paul, 

It turned out that the serial library in the mesh SDK is not capable of printing out a string so there is a buffer needed (this is implemented inside the serial.c library which related to mesh serialization, which we don't plan to use here). 
So we need to use the app_uart library in nRF5 SDK instead (this is the library that the log in nRF5 SDK uses).

I attached here the example I made for SDK v4.0 . Basically you need to add app_fifo, app_uart_fifo and retarget.c 
log.c is modified to log_serial.c to print out to serial instead of RTT. 
light_switch - SerialLog.zip