STM32F411 to NRF51822 to Android Phone

RE: STM32F411 to NRF51822 to Android Phone

royalmdm — Mon, 26 Nov 2018 07:02:43 GMT

As you said, I am trying to find a reason why it shouldn't be revised from the beginning.

First, I tried to communicate using nrf51822 and Android phones. and I did. NRF RTT confirmed sending and receiving data.

Second, it started Nrf51822 and UART communication from STM32 to UART, and matched pin map and baudrate.

Now I use the NRF RX pin 4, TX pin is 5..

But, in the example app_uart, button is using pin 4. There is no pin 4 on my board, so I did not modify it at that time. now, I started to change.

First, I changed the pinmap of button and Ble started to stop working. So I annotated the button, but this time, I started to get an error. I immediately began to sort out the functions of the button.

And after that, Finally, I sent a string using the printf function from nrf to stm32. There's a phrase coming out of the stm32 debug port.

But still Data sent from stm32 to nrf are not verified.

You seem to be making some progress.
Thank you.

RE: STM32F411 to NRF51822 to Android Phone

awneil — Fri, 23 Nov 2018 11:01:23 GMT

[quote userid="75346" url="~/f/nordic-q-a/40798/stm32f411-to-nrf51822-to-android-phone/158779"]I changed RX_TX_PIN NUMBER also.. my custom rx pin is 5, tx pin is 4..[/quote]

But before doing that, did you use the RTT logging to see what's happening inside the code, and understand the flow of the data through the code?

[quote userid="75346" url="~/f/nordic-q-a/40798/stm32f411-to-nrf51822-to-android-phone/158779"]that's why i start to use stm32[/quote]

Did you check that your code still works by using TeraTerm before moving to the STM32?

This really is key to successful development: take small steps; only change one thing at a time!

[quote userid="75346" url="~/f/nordic-q-a/40798/stm32f411-to-nrf51822-to-android-phone/158779"]I think we can use this function ' ble_nus_string_send()'... [/quote]

Don't just "think" - use the debugger and/or the RTT logging to prove it

RE: STM32F411 to NRF51822 to Android Phone

royalmdm — Fri, 23 Nov 2018 09:32:55 GMT

I checked this demo already. and, it is working...

I changed RX_TX_PIN NUMBER also.. my custom rx pin is 5, tx pin is 4..

that's why i start to use stm32.. um.. ;(

I think we can use this function ' ble_nus_string_send()'...

I sent the text from nrf51822 to nrf 51 dongle..

and, I thought NRF_UART0->RXD is date which is from stm32...

RE: STM32F411 to NRF51822 to Android Phone

awneil — Fri, 23 Nov 2018 09:19:07 GMT

So go back to the original, unmodified Nordic UART demo

http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.2.0/ble_sdk_app_nus_eval.html?cp=4_0_0_4_1_2_24

Use your serial terminal (TeraTerm) to verify that

you can send stuff from the terminal to the app;
you can send stuff from the app to the terminal.

See the 'Testing' section in the documentation.

Pay attention to the notes in the documentation about the handling on newline & carriage return.

Once you have this working, use the RTT logging to see what's happening inside the code.

Only when you have this working, and understand the flow of the data through the code, move on to connecting the STM32 ...

Note that the demo uses the virtual COM port in the on-board JLink for the connection to the PC.

You can't use that for the STM32!

Therefore your first step should be to modify the demo so that your TeraTerm connects to UART pins on the board...

RE: STM32F411 to NRF51822 to Android Phone

royalmdm — Fri, 23 Nov 2018 05:41:56 GMT

I tested the baud rate by changing it from 9600 to 115200.

I use APP_UART example and that's the whole code I changed.

and.. I don't know what will I do.. now..

RE: STM32F411 to NRF51822 to Android Phone

awneil — Thu, 22 Nov 2018 10:30:25 GMT

[quote userid="75346" url="~/f/nordic-q-a/40798/stm32f411-to-nrf51822-to-android-phone"]sending data from STM32 to NRF51 DONGLE fails[/quote]

So what have you done to debug that failure?

The Nordic UART demo should just forward whatever it receives from the hardware UART over the BLE link.

That will work exactly the same whether the data comes from a terminal, or a microcontroller or anything else - so shouldn't require any modifications at all for the STM32.

How to properly post source code: