Bit/Character limit on Central and Peripheral example

[Aashay]

I am using 2 nrf52832 boards to talk to each other through UART. One is programmed to the central SDK example and other other is peripheral. In the code, i incorporated 2 different types of app_timers. One that is a continuous loop that sends data out every desired interval. and the other type is that it waits for an input and sends it only after desired interval has passed after the most recent character. Well, i am using tera term to test the connection between the two boards. on the first config, when i use the "send file" option where i have prerecorded characters on a .txt file. there appears to be a limit on how many characters pass. it will pass upto 18 characters but restarts the UART if it is any more. on the second config, the send file only allows about 4 characters before restarting. what can i do or change to increase the amount of bits i can send simultaneously. 

[Håvard]

Hi,

I tested with SDK 15.3

ble_app_uart on one board, and ble_app_uart_c on the other. (I tested with nRF52840 and not nRF52832).

I noticed that the peripheral app, ble_app_uart, asserted when I loaded large text files (but worked fine with 18 characters and a bit more).

Digging down in the drivers I wonder if this ultimately comes from an overrun error (A start bit is received while the previous data still lies in RXD).

Enabling flow control fixed the issue for me, and let me send larger files.

Graceling explored a different workaround in this thread.

Good luck!

[Aashay]

how did you enable flow control? thanks

[Håvard]

In main.c I found the line

.flow_control = APP_UART_FLOW_CONTROL_DISABLED,

and changed it to 

.flow_control = APP_UART_FLOW_CONTROL_ENABLED,

[Aashay]

so in the program i am using. i have to connect a board and then send data through. so with the 'disabled' i would be able to connect the boards but when sending data, errors would cause failure. with 'enabled' on the same code, i am not able to even connect my board. i dont exactly know why that is. 

[Aashay]

update: so i figured out why i cant use flow control. the program i am using doesn't enable the cts and rts lines in the first place so me trying to enable them is why i was getting the error. is there any other way i could increase the how many characters or bits i can pass through the buffer at once?