nRF52 UART connection with constant data stream capability

RE: nRF52 UART connection with constant data stream capability

Vidar Berg — Fri, 06 Sep 2019 08:42:28 GMT

Please take a look at my answer in this thread for suggestions on how to detect a long button press.

RE: nRF52 UART connection with constant data stream capability

Aashay — Wed, 04 Sep 2019 14:35:59 GMT

RE: nRF52 UART connection with constant data stream capability

Aashay — Fri, 30 Aug 2019 16:04:41 GMT

Also, for the BUTTON2, how could make it so that user has to hold BUTTON2 for at least 3 seconds to terminate connection or else nothing happens. (app timer maybe?)

RE: nRF52 UART connection with constant data stream capability

Aashay — Fri, 30 Aug 2019 15:55:54 GMT

Hey Vidar Berg, sorry I should have mentioned that I was using Keil. Regardless, I was able to compile it successfully on segger embedded. I just have some questions on how to alter the code to change what the buttons and leds do.

I wanted the whole process to look like this:

Once the boards turn on, LED1 is off. When BUTTON1 is pressed, it initiates the pairing process (to search for link) on that board. and cant connect unless another board is also in the same searching process. In this process I want the LED1 to be blinking. Once the boards are connected, the LED1 stays on. I want BUTTON2 to be able to completely terminate the link and make the LED1 turn off. And to reconnect, we would repeat the process.

Is this possible? And where would this be coded/how could it be done?

Thanks so much for all the help.

RE: nRF52 UART connection with constant data stream capability

Vidar Berg — Thu, 29 Aug 2019 17:03:50 GMT

Hi, I thought you used Segger embedded Studio so that's what I used. Please try with the two projects I uploaded. It would be a bit time consuming to repeat the process and add all of the required source files and include paths to Keil.

RE: nRF52 UART connection with constant data stream capability

Aashay — Thu, 29 Aug 2019 16:05:24 GMT

hey Vidar Berg, thanks for helping out. I tried building the project and came upon an unusual building error. I got this for both central and peripheral when i tried building them.

RE: nRF52 UART connection with constant data stream capability

Vidar Berg — Thu, 29 Aug 2019 11:31:02 GMT

I have integrated the peer manager and necessary crypto libraries to support LE secure pairing. Please test and review the code.

devzone.nordicsemi.com/.../231178.zip

RE: nRF52 UART connection with constant data stream capability

Aashay — Wed, 28 Aug 2019 14:48:05 GMT

Vidar Berg, I have uploaded the central and peripheral. I'm sure everything needed is in there. Please let me know if something is missing. Thank you for being a huge help.

devzone.nordicsemi.com/.../Peripheral-UART.zip

devzone.nordicsemi.com/.../Central-UART.zip

RE: nRF52 UART connection with constant data stream capability

Vidar Berg — Wed, 28 Aug 2019 09:35:20 GMT

Hi, thanks for linking to the other thread. I can try to integrate the PM module into your projects if you upload them here?

RE: nRF52 UART connection with constant data stream capability

Aashay — Tue, 27 Aug 2019 16:33:58 GMT

Hey Vidar Berg, I have a fully functioning code for my central and peripheral uart. I was wondering if it is possible to, and if so how to, make the pairing process secure between the 2 boards. As of now, after I program the examples, the boards just connect automatically and both LED1's turn on. I was wondering if we could make the pairing process start after pressing BUTTON1 on the boards. And then when they successfully pair, the LED1's turn on. And then BUTTON2 would reset the device and disconnect with any paired devices. Any help is great. If you know how to do it or have done something similar, please share in detail or even share your code if you're willing. I have started a new thread, but so far it has been unhelpful because I don't exactly have experience in this. Thanks!!

RE: nRF52 UART connection with constant data stream capability

Vidar Berg — Wed, 24 Jul 2019 06:24:57 GMT

Hi,

Were you able to view the debug log from the boards? It should be enough to attach the debugger then open the project in Segger embedded studio and start a debug session. The log should then be shown in the "Debug terminal" view:

Also, can you try the two projects I sent without modifying them and see if you get the same result?

RE: nRF52 UART connection with constant data stream capability

Aashay — Mon, 22 Jul 2019 16:43:14 GMT

Vidar Berg another update: so with the same code, i am running at different baudrates. at 921600 when i try to send a file .txt, only 6 characters pass through. but when the baudrate is 9600 or even 19200, i can accurately send over 100+ characters without any error. the buffer sizes are 256 for tx and rx. so what could be causing the data to be incomplete at baud rates after 19200?

RE: nRF52 UART connection with constant data stream capability

Aashay — Fri, 19 Jul 2019 20:19:39 GMT

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 and wouldnt connect. is there any other way i could increase the how many characters or bits i can pass through the buffer at once? i tested the code with the error handler commented out on tera term and it didnt help increase how many bits i can send through the buffer at once. if i were to put "123456789123" in a .txt file. before it would just handle the error and restart the uart. but now it sends only the first 6 bits so "123456". since i cant use flow control and the error handler doesn't change my results. what other options can i use to increase how much i can pass through my buffer. also why is the buffer being limit to such a small character limit?

RE: nRF52 UART connection with constant data stream capability

Aashay — Fri, 19 Jul 2019 19:44:42 GMT

i tried using the flow control option and also commented out the APP_ERROR... so in the program i am using. i have to connect a board and then send data through. so with the 'disabled' flowcontrol 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. also how would i use easyDMA or incorporate it?

RE: nRF52 UART connection with constant data stream capability

Vidar Berg — Fri, 19 Jul 2019 07:25:27 GMT

You can't use any value for the mask.

From tx_buffer.h

#define TX_BUFFER_MASK 0x0F //!< TX buffer mask. Must be a mask of contiguous zeroes followed by a contiguous sequence of ones: 000...111.

RE: nRF52 UART connection with constant data stream capability

Vidar Berg — Fri, 19 Jul 2019 07:22:43 GMT

EasyDMA gives UARTE direct access to RAM without requiring the CPU. This means that you can receive data while the CPU is busy with other tasks. And you get flow control if you enable the CTS and RTS pin.

Try to comment this line "APP_ERROR_HANDLER(p_event->data.error_communication);" and see if it helps. It will make the app ignore "Error conditions"

RE: nRF52 UART connection with constant data stream capability

Aashay — Thu, 18 Jul 2019 15:48:08 GMT

also, i see that in tx_buffer.h that you shared. the buffer mask is set to 0x0F which is 15. I tried changing this value to see if it would work and increase the buffer size but any value other than 0F didn't work.

RE: nRF52 UART connection with constant data stream capability

Aashay — Thu, 18 Jul 2019 14:45:31 GMT

im sorry i have no idea what easyDMA or flow control is. i tried tried reading about it in the infocenter but i dont understand how i would use it.

RE: nRF52 UART connection with constant data stream capability

Vidar Berg — Thu, 18 Jul 2019 09:17:19 GMT

Debug logging should be enabled in the example projects, so you can use that to determine why it resets. I guess you will probably need to use easyDMA or flow control to receive larger chunks of data reliably.

RE: nRF52 UART connection with constant data stream capability

Aashay — Wed, 17 Jul 2019 20:30:55 GMT

additional update.Vidar Berg so the 19 character limit was before i incorporated the stop and start in APP_UART_DATA_READY. After using this, the functionality i am looking for works great. but in the send file option this character limit was brought down to about 4 characters. any more and it restarts the uart. So basically without the start & stop in the uart_event_handle the limit is 19 bits and with the start & stop, the limit is roughly 4 (i didn't test exactly. I tested 4 and it works and tested 8 and doesn't work so somewhere in between). so what would be causing this? and how can we make this limit bigger so that I can send files that can be at least a few dozen characters?

RE: nRF52 UART connection with constant data stream capability

Aashay — Wed, 17 Jul 2019 14:06:43 GMT

ok thanks so much. One more question. So using the app timer examples for both central and peripheral on teraterm, I used the send file option where I prerecorded characters on a .txt file. well both boards send the file as long as it is only 19 characters or less. if it goes above 19 characters, the uart restarts. how can i increase this size to something bigger?

RE: nRF52 UART connection with constant data stream capability

Vidar Berg — Wed, 17 Jul 2019 06:29:49 GMT

Hi, you can try to call app_timer_stop() followed by app_timer_start() in the APP_UART_DATA_READY event. This should restart the timer every time you receive a byte on the UART interface.

RE: nRF52 UART connection with constant data stream capability

Aashay — Tue, 16 Jul 2019 16:11:52 GMT

Hey, so i was thinking of a possible way to alter the timer. I wanted to make the timer so that it is dependent on the input rather than being a continuous timer loop. As of right now, I have the interval at about 50 ticks ( 50 ms ), and it seems fine but i feel changing this would fix some of the problems I am having. If i wanted to make it to where, everytime a character/bit of data is added to the array, the timer is reset. so as long as data keeps coming in, the timer keeps resetting. When the last bit of data were to come in, there would not be another for it to reset the timer. This is where the timer could turn on and send the data array at the end of the interval and stay on until the next bit is received and resets the timer. Is this possible at all. It seems simple in terms of logic but im sure it could be troublesome in the syntax.

RE: nRF52 UART connection with constant data stream capability

Vidar Berg — Tue, 16 Jul 2019 06:19:45 GMT

Hi,

It sounds like there may be a bug in the program you use, and based on the error, I guess you have access to the source code. I would suggest to debug the program and figure out where "nullable objects must have a value" gets returned.

RE: nRF52 UART connection with constant data stream capability

Aashay — Mon, 15 Jul 2019 17:40:06 GMT

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.