I am a beginner for BLE. I want my ble to communicate with my nrf android app.

[Abhimanyu K K]

I am using Keil uvision. Working with example codes, with uart example I got the code to send a data to mobile app through ble. But I cannot find code for receiving a data by ble which is send from the mobile app. Please help me. I need a code, such that when I send a data (let it be "ON") from my mobile to the connected ble , a led must ON. And similarly when I send "OFF" the led must OFF.

[wlgrd]

Download this app https://play.google.com/store/apps/details?id=no.nordicsemi.android.nrfblinky

Use the firmware found in <SDK>\examples\ble_peripheral\ble_app_blinky

Out of the box, this does exactly what you want. 

Source code for the Android application: github.com/.../Android-nRF-Blinky

[Abhimanyu K K]

I am using St link,  while flashing blinky pgm there come an error box showing no L-link found.

So I need the codes for just receive and take the data send from the app.

[wlgrd]

The code for the mobile app, or the code running on the hardware? What hardware are you using here? What chip? 

[Abhimanyu K K]

MDBT40. I need the firmware to flash inside this. I'm doing it in keil uvision5

[wlgrd]

Well, even though it sits an nRF51822 on this module, Nordic is not selling or supporting this module directly. You have to take our example and adapt it according to the layout of the module itself. I don't know if the SDK examples should work out of the box for this board. There has been others https://devzone.nordicsemi.com/f/nordic-q-a/9911/programming-raytac-mdbt40-nrf51822-based-for-led-blinking who apparently has had some success for this board, just using the SDK.

No J-Link found means that the j-link driver hasn't seen any chip connected to your debugger. You should also verify that to begin with. It may find the programmer, but not the actual nrf. 

It seems to me, that the PCA10028 examples should work, at least for LED's. 

[Abhimanyu K K]

You are right but I flashed 2 example pgms, UART and Beacon. It is perfectly ok. It is sending a String continuously in the UART pgm. But I need to send a data back to BLE. so I need that code only.

OK lets you give me a whole pgm: By sending a data '1' to BLE through nRF UART application from mobile, one of the GPIO led must ON, and when a '0' is send, that LED must OFF.

[Ashish]

Hey,

With UART program, i am guessing you have tried the ble_uart program.

In that case, you should have a nus_data_handler function defined. Inside that function you can look for BLE_NUS_EVT_RX_DATA event. You will get your data sent from the mobile device which you can check and actuate accordingly.

[Abhimanyu K K]

static void nus_data_handler(ble_nus_t * p_nus, uint8_t * p_data, uint16_t length)
{
for (uint32_t i = 0; i < length; i++)
{
// getData(p_data, bleRecData, i);

while (app_uart_put(p_data[i]) != NRF_SUCCESS);
}
while (app_uart_put('\r') != NRF_SUCCESS);
while (app_uart_put('\n') != NRF_SUCCESS);
}

There is no BLE_NUS_EVT_RX_DATA .

[Bjørn Kvaale]

Abhimanyu K K Are you referring to UART & Blinky programs provided by ST-Link? Or the ones in the nRF5 SDK?

There are multiple ways you can do this. As mentioned, you can modify the ble_uart program to blink a led when you write 0x0 or 0x1 from the mobile phone to the peripheral device. Otherwise, you could also take a look at the ble_app_blinky example provided in the nRF5 SDK & create a new boards file that will work with your MDBT40.

[Abhimanyu K K]

I got the answer. I am now able to send data (string) from my mobile to BLE device.

In the main loop I didn't write any code. In main() function there are some function call statements as it is in the BLE UART example pgm.

while(1)
	 {
		 if(i==500)
		 {
		  i=0;
		 }
		power_manage();
	 }

But I coded inside the nus_data_handler() function.

static void nus_data_handler(ble_nus_t * p_nus, uint8_t * p_data, uint16_t length)
{

	uint8_t k=0;
	if (strstr((char*)(p_data), "on")) {
    nrf_gpio_pin_write(1,1);
		printf("ON");
  }
	
	else if (strstr((char*)(p_data), "off")) {
    nrf_gpio_pin_write(1,0);
		printf("OFF");
  }
	
	else if(strstr((char*)(p_data), "toggle")) {
		while(k<10){
		nrf_gpio_pin_toggle(1);
		printf("TOGGLE");
			Delay_ms(100);
			k++;
		}
  }
	
}

When I send "on" from my mobile, then the GPIO pin 1 will become high.

And when I send "off" , the GPIO pin 1 will set low.

And at last, when I send "toggle", the pin 1 will start toggle for 10 times, as I coded.