Bluetooth transfer speed is slow.

RE: Bluetooth transfer speed is slow.

Simonr — Mon, 19 Sep 2022 07:17:04 GMT

There are multiple parameters that can help increase the throughput, and you should begin by using the 2MBPS PHY, as well as enabling extended advertising to increase MTU and data length, and update the connection parameters/interval. All of this is done with functions like these which are used in the throughput example:

static bool le_param_req(struct bt_conn *conn, struct bt_le_conn_param *param)
{
	printk("Connection parameters update request received.\n");
	printk("Minimum interval: %d, Maximum interval: %d\n",
	       param->interval_min, param->interval_max);
	printk("Latency: %d, Timeout: %d\n", param->latency, param->timeout);

	return true;
}

static void le_param_updated(struct bt_conn *conn, uint16_t interval,
			     uint16_t latency, uint16_t timeout)
{
	printk("Connection parameters updated.\n"
	       " interval: %d, latency: %d, timeout: %d\n",
	       interval, latency, timeout);

	k_sem_give(&throughput_sem);
}

static void le_phy_updated(struct bt_conn *conn,
			   struct bt_conn_le_phy_info *param)
{
	printk("LE PHY updated: TX PHY %s, RX PHY %s\n",
	       phy2str(param->tx_phy), phy2str(param->rx_phy));

	k_sem_give(&throughput_sem);
}

Best regards,

Simon

RE: Bluetooth transfer speed is slow.

cheng_799 — Fri, 16 Sep 2022 04:05:43 GMT

I have read two examples. can you please tell me how to improve the transmission speed of the nus service? I checked the throughput example according to your instructions, but I still don't understand how to set the nus sample. I measured the speed of the peripheral sample is only 6.4kbps. How can I set it to reach about 800kbps in the throughput sample.

RE: Bluetooth transfer speed is slow.

Simonr — Thu, 15 Sep 2022 08:02:21 GMT

The data is not stored in flash on the peripheral side, it is only temporarily stored in a buffer before forwarded to the UART terminal over the UART peripheral. You can see the UART_RX_RDY, UART_RX_BUF_REQUEST in the peripheral UART example to see how this is handled.

Best regards,

Simon

RE: Bluetooth transfer speed is slow.

cheng_799 — Wed, 14 Sep 2022 01:56:41 GMT

Thank's for your advise. In addition, we want to know where the data received by the peripheral is stored. We looked through the routines and found no relevant code

RE: Bluetooth transfer speed is slow.

Simonr — Tue, 13 Sep 2022 11:38:23 GMT

If your computer support Bluetooth Low Energy, this should be possible, but we don't have a computer application that works as a Bluetooth central. You can use the nRF Connect for Desktop BLE app, but that requires a DK connected to the computer to act as the central device, where data is going from one DK to the one connected to the computer, and then forwards that to the computer.

Best regards,

Simon

RE: Bluetooth transfer speed is slow.

cheng_799 — Tue, 13 Sep 2022 02:45:06 GMT

In addition, we did not find out where the int bt_throughput_read(struct bt_throughput *throughput) stores the data. We have no clue how to get the received data.

RE: Bluetooth transfer speed is slow.

cheng_799 — Mon, 12 Sep 2022 09:08:52 GMT

T'hanks for your answer. We have read the sample you mentioned. We found this program to transfer data between two development kits. If it is to transfer data between the development kit and the computer, is such a solution still feasible?

RE: Bluetooth transfer speed is slow.

Simonr — Fri, 09 Sep 2022 13:13:47 GMT

From what you explain here, it seems like you're not handling the received data correctly (checking that it all arrives and is handled) before sending more. I would recommend checking out our Throughput sample to see how transmitting and receiving big amounts of data is handled there. There must be some error message on your end that you're not checking for or ignoring.

Best regards,

Simon

RE: Bluetooth transfer speed is slow.

cheng_799 — Fri, 09 Sep 2022 09:57:13 GMT

We want to know how to solve the problem of real-time transmission and packet loss