nRF52 UART connection with constant data stream capability

[Aashay]

Hello, I am working on a project where I have 2 nRF52832 boards with the PCA10040. I have the example developer code examples. I am using the central and peripheral code examples to talk from one UART to another on Tera Term. Although, I noticed that this code is structured so that data is piled in an array and only sent to the other UART when I press "enter" or if it reaches a maximum size (which is very large). I am only using Tera Term to test my boards and not as part of the project. I have an external source of data that works properly on its own and am trying to use these UARTs to establish wireless communication. I have cut the solder bridges SB 22-25 to isolate PO.05 - PO.08 from nRF52832 to the Interface MCU. In pins 6 and 8 on both boards, I put TXD and RXD. Essentially what I am trying to do is have data go though the TXD & RXD wires to one UART, then wirelessly transfer data to the other UART, and have TXD & RXD wires come back. This processes will not work unless the code is structured so that data can be processed (sent & received) continuously. Or at least have it to where whatever is stacked up in the buffer is sent out every interval. I have attached the part of the code for both Central and Peripheral examples that specifically deal with data in UART. I have also put a diagram of sorts to help visualize. Any help would be great. Thanks.

[Aashay]

Unfortunately, I have not been able to get it to work. I have used what you have in your posted code. My question is that how would we use this in the uart_event_handle. There is an if statement in the function that makes the array return only if it detects a "\n" in the array or the array reaches max size. I was wondering on how to replace this with the app timer functionality to send the array in time intervals. Is there any way to do that. If so, how would I go about doing that? Thanks.

[Vidar Berg]

Hi,

Please try the attached example below and see if it works for you. I added a ring buffer to hold the UART data between timer events, see tx_buffer.c adjacent to main.c.

ble_app_uart_mod.zip

Note: this example requires SDK 15.3.0. Extract the folder to \nRF5_SDK_15.3.0_59ac345\examples\ble_peripheral before building the project.

[Aashay]

Hey Vidar Berg, this works really well for the peripheral example. I was trying to incorporate this into the central example since I am working with two boards, but the syntax for the 2 examples differs greatly. Is there any way you have something just like this for the central uart example.

[Vidar Berg]

Hi, yes here is the central/client version:

ble_app_uart_c_mod.zip

[Aashay]

hey Vidar Berg thanks so much for these. So i tried them out on tera term to confirm that they work and they do work correctly. so i used this configuration for the actual data i am trying to pass through the two boards. The program i am using connects and recognizes the boards, but when i try to pass data through, it gives an error saying "nullable objects must have a value". I am pretty sure that this program passes data in hex and many times it sends NULL, which is 0x00 in hex. I predict that our code isnt sending this properly. it might be not sending NULL altogether, which might be why there is an error? any recommendations on what to do or where to start? If my explanation doesn't make sense, just let me know. i can try to explain it better.