Connecting UART Data to development board PCA10040

RE: Connecting UART Data to development board PCA10040

sherif — Mon, 15 Jul 2019 01:27:38 GMT

The next problem i have:

it worked once and then i slept the pc and when i opened it again, it did not work any more. But i could see it sending 255 and then 1s. Is there a problem with ttl level?

RE: Connecting UART Data to development board PCA10040

sherif — Mon, 15 Jul 2019 01:13:10 GMT

Solved:

Here is the solution:

1- Use pin 3 and 2 and disable the rts and cts

static void uart_init(void)
{
    uint32_t                     err_code;
    app_uart_comm_params_t const comm_params =
    {
        .rx_pin_no    = 3, //RX_PIN_NUMBER,
        .tx_pin_no    = 2,//TX_PIN_NUMBER,
//        .rts_pin_no   = 17, //RTS_PIN_NUMBER,
//        .cts_pin_no   = 18, //CTS_PIN_NUMBER,
        .flow_control = APP_UART_FLOW_CONTROL_DISABLED,
        .use_parity   = false,
#if defined (UART_PRESENT)
        .baud_rate    = NRF_UART_BAUDRATE_115200
#else
        .baud_rate    = NRF_UARTE_BAUDRATE_115200
#endif
    };

    APP_UART_FIFO_INIT(&comm_params,
                       UART_RX_BUF_SIZE,
                       UART_TX_BUF_SIZE,
                       uart_event_handle,
                       APP_IRQ_PRIORITY_LOWEST,
                       err_code);
    APP_ERROR_CHECK(err_code);
}

2- don't connect any leds because it seems that drawing any amount of rel. current will disable the data transfer

3- connect board A (serial to usb) to board B (PCA10040)

Gnd-Gnx

Rx (board A) - Pin 2 (Board B)

Tx (board A) - Pin3 (Board B)

4- Install the mac usbto serial port driver (or use Serial app because it has internal drivers but cost 25$)

My driver was based on this link

https://blog.sengotta.net/signed-mac-os-driver-for-winchiphead-ch340-serial-bridge/

5- Using cool Term connect to your usb-serial port

6- using segger

in my main loop i sent 1 and 255 for testing

    for (;;)
    {
        idle_state_handle();
               uint32_t err_code = app_uart_put(1);
                if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_BUSY))
                {
                    NRF_LOG_ERROR("Failed receiving NUS message. Error 0x%x. ", err_code);
                    APP_ERROR_CHECK(err_code);
                }
                else
                {
                     NRF_LOG_ERROR("received data");
                }
            
    }

7- if you connection is correct, you should see the 1 (byte sent) in cool term

RE: Connecting UART Data to development board PCA10040

sherif — Sun, 14 Jul 2019 15:38:06 GMT

Lets rephrase my question. I have the following simple code in the main, based on ble_app_uart. it initializes the uart and writes data to it. First i see UART started on the terminal. Second i want to see these bits. When i connect a led to pin 23 which i used for Tx, i don't see any thing.

    uint32_t                     err_code;
    app_uart_comm_params_t const comm_params =
    {
        .rx_pin_no    = RX_PIN_NUMBER,
        .tx_pin_no    = SER_CON_TX_PIN, //TX_PIN_NUMBER,
        .rts_pin_no   = RTS_PIN_NUMBER,
        .cts_pin_no   = CTS_PIN_NUMBER,
        .flow_control = APP_UART_FLOW_CONTROL_DISABLED,
        .use_parity   = false,
#if defined (UART_PRESENT)
        .baud_rate    = NRF_UART_BAUDRATE_115200
#else
        .baud_rate    = NRF_UARTE_BAUDRATE_115200
#endif
    };



int main(void)
{
    uart_init();
    printf("\r\nUART started.\r\n");
    for (;;)
    {
        idle_state_handle();
               uint32_t err_code = app_uart_put(255);
                if ((err_code != NRF_SUCCESS) && (err_code != NRF_ERROR_BUSY))
                {
                    NRF_LOG_ERROR("Failed receiving NUS message. Error 0x%x. ", err_code);
                    APP_ERROR_CHECK(err_code);
                }
                else
                {
                     NRF_LOG_ERROR("received data");
                }
            
    }
}

RE: Connecting UART Data to development board PCA10040

sherif — Fri, 12 Jul 2019 22:43:56 GMT

i have been working with this issue now 1 week, and investigated many things, but i can not input data externally. I need a step by step guide. Guys, if you made it previously, please assist me how to do it. I changed the pin assignments for RX and TX but it does not make any change

RE: Connecting UART Data to development board PCA10040

sherif — Fri, 12 Jul 2019 22:40:18 GMT

I made this. But when i change the pins, nothing is getting into action. I can not disable the on board usb to uart and input external serial data. It seems that the pins need to be changed in many places. I need help or a step by step to solve it. I am now 3 days on it.

RE: Connecting UART Data to development board PCA10040

awneil — Fri, 12 Jul 2019 15:00:10 GMT

I think you need to go back to the unmodified UART example in the SDK.

Spend time with the debugger, a terminal, and an oscilloscope exploring that, and understanding how it works.

Use the oscilloscope to observe the data between the nRF52 to the on-board USB-to-UART.

Once you have this thoroughly understood, then - and only then - move on to modify that example to talk to a separate USB-to-UART converter.

Once you have that working, then you can move on to getting 2 boards to talk to each other.

RE: Connecting UART Data to development board PCA10040

sherif — Fri, 12 Jul 2019 14:46:27 GMT

how can I run the external serial port ? these stuff are not clear even there is no example. should I use HWFC?

RE: Connecting UART Data to development board PCA10040

awneil — Fri, 12 Jul 2019 14:40:14 GMT

[quote userid="81584" url="~/f/nordic-q-a/49703/connecting-uart-data-to-development-board-pca10040/198213"]the schematics is not clear[/quote]

In what way(s), exactly, is it unclear?

[quote userid="81584" url="~/f/nordic-q-a/49703/connecting-uart-data-to-development-board-pca10040/198213"]is there any internal chip configuration[/quote]

The firmware running in the chip does the configuration.

RE: Connecting UART Data to development board PCA10040

sherif — Fri, 12 Jul 2019 14:32:11 GMT

what is could reach right now, when I press a button I come to this line

    NRF_BREAKPOINT_COND;
    // On assert, the system can only recover with a reset.

RE: Connecting UART Data to development board PCA10040

awneil — Fri, 12 Jul 2019 14:22:06 GMT

[quote userid="81584" url="~/f/nordic-q-a/49703/connecting-uart-data-to-development-board-pca10040/198213"]the schematics is not clear[/quote]

In what way(s), exactly, is it "not clear" ?

[quote userid="81584" url="~/f/nordic-q-a/49703/connecting-uart-data-to-development-board-pca10040/198213"]is there any internal chip configuration[/quote]

The firmware in the chip configures it.

RE: Connecting UART Data to development board PCA10040

sherif — Fri, 12 Jul 2019 14:18:31 GMT

the schematics is not clear .. is there any internal chip configuration on the mcu level?

RE: Connecting UART Data to development board PCA10040

awneil — Fri, 12 Jul 2019 13:39:44 GMT

How did you hope to get anywhere without the schematics?!

😮

On the Dev Kit Product page, they are under 'Downloads'

RE: Connecting UART Data to development board PCA10040

sherif — Fri, 12 Jul 2019 13:03:26 GMT

I used now pin 23 and 24 but still it does not work.

I get the system can only recover with a reset, do you know how can I reset the Segger?

RE: Connecting UART Data to development board PCA10040

sherif — Fri, 12 Jul 2019 12:44:58 GMT

do you know where is the schematics? I don't have it.

RE: Connecting UART Data to development board PCA10040

awneil — Fri, 12 Jul 2019 11:18:06 GMT

[quote userid="81584" url="~/f/nordic-q-a/49703/connecting-uart-data-to-development-board-pca10040/198129"]I see in pca10040.h[/quote]

So look where those definitions get used - that's where you need to change to your own settings.

You still need to check that any other pins you might want to choose are not "occupied" by other things on the board.

I find the easiest way is to look at the schematics.

But the information is also in the User Guide.

RE: Connecting UART Data to development board PCA10040

RoyCreemers — Fri, 12 Jul 2019 11:13:57 GMT

Does not really mather, as long as you make sure that

A.RX <--> B.TX

A.TX <--> B.RX

RE: Connecting UART Data to development board PCA10040

sherif — Fri, 12 Jul 2019 11:11:48 GMT

which pins should I use?

I see in pca10040.h the following:

#define RX_PIN_NUMBER  8
#define TX_PIN_NUMBER  6
#define CTS_PIN_NUMBER 7
#define RTS_PIN_NUMBER 5

RE: Connecting UART Data to development board PCA10040

sherif — Fri, 12 Jul 2019 11:08:20 GMT

how can I use different pins?

RE: Connecting UART Data to development board PCA10040

RoyCreemers — Fri, 12 Jul 2019 10:56:09 GMT

In case p0.6 is configured as TXD, you have connected it incorrectly. RXD on board A must be connected to TXD of board B

RE: Connecting UART Data to development board PCA10040

awneil — Fri, 12 Jul 2019 10:54:33 GMT

Yes - those are the pins used by the on-board USB-to-UART.

So, if you're trying to connect an off-board device, you are either going to have to disconnect that, or use different pins.

RE: Connecting UART Data to development board PCA10040

sherif — Fri, 12 Jul 2019 10:45:51 GMT

I know it has an on-board-usb-to serial converted but the target here is to transfer data from another device to this board. As far as I understand, when I checked the board pin assignment it says in page 8, p0.06 is TXD and pin 0.08 RXD. Please correct me if I misunderstood it.

infocenter.nordicsemi.com/.../nRF52_DK_User_Guide_v1.2.pdf

RE: Connecting UART Data to development board PCA10040

awneil — Fri, 12 Jul 2019 10:38:34 GMT

[quote userid="81584" url="~/f/nordic-q-a/49703/connecting-uart-data-to-development-board-pca10040"]connected to pin 06 on board B[/quote]

Have you checked carefully that there is nothing on the board already "occupying" that pin?

In particular, remember that the PCA10040 has an on-board USB-to-Serial converter connected to the nRF52 chip...

Check the User Guide & Schematics ...