How to send sensor data using AT commands to a device using Uart in segger embedded studio

[Rajbir Singh]

Hi, I am new to NRF and segger embedded studio.

So I want to send temperature sensor data connected with nrf52840 DK to the Murata1_SC  device using UART.

The data will be sent using AT Commands.

So how to send AT Commands in Segger embedded studio.

Thank you for the help in advance.

[Rajbir Singh]

#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include "app_uart.h"
#include "app_error.h"
#include "nrf_delay.h"
#include "nrf.h"
#include "bsp.h"
#include "nrf_uart.h"

#define UART_TX_BUFF_SIZE 128
#define UART_RX_BUFF_SIZE 128

#define UART_HWFC APP_UART_FLOW_CONTROL_DISABLED

void uart_err_handle(app_uart_evt_type_t * p)
{
  

}

int main(void)
{
  uint32_t err_code;

  bsp_board_init(BSP_INIT_LEDS);
  
  const app_uart_comm_params_t com_params = 
   {
    RX_PIN_NUMBER,
    TX_PIN_NUMBER,
    RTS_PIN_NUMBER,
    CTS_PIN_NUMBER,
    UART_HWFC,
    false,
    NRF_UART_BAUDRATE_115200
    };

  APP_UART_FIFO_INIT(&com_params, UART_RX_BUFF_SIZE, UART_TX_BUFF_SIZE, uart_err_handle, APP_IRQ_PRIORITY_LOWEST, err_code);

  APP_ERROR_CHECK(err_code);
  
  printf("Hello PC from Nordic Device!!!\r\n");
  
  while(true)
  {
    uint8_t cr;

    while(app_uart_get(&cr) != NRF_SUCCESS);//wait here for the character from pc
    if(cr == 'o')
    {
      bsp_board_leds_on();
      printf("Leds are ON\r\n");
    }
    if(cr == 'f')
    {
      bsp_board_leds_off();
      printf("Leds are OFF\r\n");
    }
  }
}

[Rajbir Singh]

I have seen this code

uart_putstring((uint8_t*)"AT\r");
nrf_delay_ms(2000);
uart_putstring((uint8_t*)"AT+CMGF=1\r");
       nrf_delay_ms(2000);
uart_putstring((uint8_t*)"AT+CMGS=\"8919242248\"\r");
   nrf_delay_ms(2000);
   uart_putstring((uint8_t*)"test\r");
          nrf_delay_ms(2000);
          app_uart_put((char)0x1A);   ///used (uint8_t) 26 also but no response..
                 nrf_delay_ms(1000);

in this link, where someone is saying to wait for the response, so how can i do that.

[Hung Bui]

Hi,

What's the exact issue you are having ? 
Can you develop your app based on the uart example in the SDK or the example that you found working above ? 

I don't really understand what you meant by Software UART ? 

What did you mean by "hardware UART is used by debugger" ? 
Calling this: 

#define RX_PIN_NUMBER 27 //8
#define TX_PIN_NUMBER 26 //6
#define CTS_PIN_NUMBER 12 //7
#define RTS_PIN_NUMBER 11 //5

Will degine the RX pin to pin P0.27 on the chip. TX pin to P0.26 on the chip, and so on. 

[awneil]

Hung Bui said:

don't really understand what you meant by Software UART

I presume he means bit-banging it in software?

Doesn't seem much point in doing that when the nRF52840 has 2 "real" (ie, hardware) UARTS?

Hung Bui said:

RX pin to pin P0.27 on the chip. TX pin to P0.26

How does it work for P1.xx pins ?

[Rajbir Singh]

basically, I want to send AT commands to an LTE Module using nrf52840, so I used the UART example in the example folder of nrf sdk 17.0.2.

But I have read its response back to see what I get.

Si I have read m Q&A on devzone.nordicsemi.com.

Some are saying P0.05 to P0.08 is used by J-Link.

So I am confused, so which pins should I use to communicate and how to change the pins in the code.

Actually I am new to nrf and segger so i have some basic questions also

And

printf("AT\n")

is used to send data through UART.

But how can I check the data in the output console, means which command is used to print data in the output console

is it

NRF_LOG_INFO("AT/n");

or

app_uart_put()

Please help

[Rajbir Singh]

awneil said:

don't really understand what you meant by Software UART

it is like SoftwareSerial lib in Arduino, by using this we can make any I/O pins as Rx and Tx.

[awneil]

Rajbir Singh said:

Some are saying P0.05 to P0.08 is used by J-Link.

That would refer to a Nordic Dev Kit - you could easily check this in the User Manual and/or schematics for that Dev Kit.

In that case you would, indeed, need to choose different pins - or use the other UART.

Rajbir Singh said:

which pins should I use

As stated earlier, with just a few restrictions, you are free to choose any pins you like.

Rajbir Singh said:

how to change the pins in the code

Using the macro definitions shown above.

Rajbir Singh said:

I am new to nrf and segger

Do you have any experience with ant other microcontroller(s) and/or any other IDE(s) ?

Rajbir Singh said:

how can I check the data in the output console

As with any other microcontroller, you would need to connect some sort of monitor onto the wires connecting the nRF to the modem

See:

https://www.avrfreaks.net/comment/2336161#comment-2336161

https://www.avrfreaks.net/comment/2306116#comment-2306116