Communicate two microcontrollers via BLE

[msu7xi]

Hello,

I'm using a nRF52 DK to test BLE communication with another microcontroller. What I need to test is the nRF52 pairing with another brand microcontroller, send a data stream and close the connection.

Could you please tell me which example from the Bluetooth samples list I can use for starting?

Thanks for your attention.

Regards,

[Vidar Berg]

I am not able to spot any errors in your implementation. Could you upload the full project so I can try reproducing this here?

[msu7xi]

Attached you will find the full project.

5226.central_uart.zip

[Vidar Berg]

I see the problem now: your main loop is always running as you have commented the k_fifo_get() function. 

As a test, try to add a call to k_msleep(1000); in your loop. This will allow the other threads such as the system workqueue to run. 

[msu7xi]

Thanks! Now the connection is established but the pairing still doesn't work. I have uncommented the 'bt_nus_client_send' and 'k_sem_take' functions but no data is received by the ESP32 and the pairing fails after some time:

*** Booting Zephyr OS build v3.2.99-ncs2 ***
bt_conn_auth_cb_register
bt_conn_auth_info_cb_register err: 0
bt_enable err: 0
Bluetooth initialized
uart_init
scan_init
Address filter added 60:55:F9:F5:29:D2 (public)
Scan module initialized
bt_nus_client_init
NUS Client module initialized

Starting Bluetooth Central UART example
scan err: 0
Scanning
Scanning successfully started
Failed to send data over BLE connection(err -128)
NUS send timeout
connected conn_err: 0
Connected: 60:55:F9:F5:29:D2 (public)
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Failed to send data over BLE connection(err -128)
NUS send timeout
Pairing failed conn: 60:55:F9:F5:29:D2 (public), reason 9
Service discovery completed
NUS send timeout

Do you know why this could be happening?

[Vidar Berg]

Did you add k_msleep(1000) to your main loop? Like this:

	...
	for (;;) {
		/* Wait indefinitely for data to be sent over Bluetooth */
		//struct uart_data_t *buf = k_fifo_get(&fifo_uart_rx_data,
		//				     K_FOREVER);

		struct uart_data_t *buf;
		buf->data[0] = 0;
		buf->data[1] = 1;
		buf->data[2] = 2;
		buf->len = 3;

		//err = bt_nus_client_send(&nus_client, buf->data, buf->len);
		if (err) {
			LOG_WRN("Failed to send data over BLE connection"
				"(err %d)", err);
			printk("Failed to send data over BLE connection"
				"(err %d)\n", err);
		}

		//err = k_sem_take(&nus_write_sem, NUS_WRITE_TIMEOUT);
		if (err) {
			LOG_WRN("NUS send timeout");
			//printk("NUS send timeout\n");
		}

		k_msleep(1000);
	}