nRF Connect for Desktop max throughput

RE: nRF Connect for Desktop max throughput

mhassan@thoughttechnology.com — Sat, 09 Apr 2022 21:29:57 GMT

I'm not sure you are talking about connecting to PC BT adapter but by this configuration in C# I could achieve more than 800K :

Laptop BT adapter:

LMP 10

Bluetooth Core Specification 5.1

** : before that I'd been using Lirad BT820-2 dongle It didn't work more than 220K

ATT MTU size: 247
hvn_tx_queue_size = 32
#define NRF_SDH_BLE_GAP_EVENT_LENGTH MSEC_TO_UNITS(30, UNIT_1_25_MS)
#define MIN_CONN_INTERVAL MSEC_TO_UNITS(30, UNIT_1_25_MS)
#define MAX_CONN_INTERVAL MSEC_TO_UNITS(30, UNIT_1_25_MS)
.tx_phys = BLE_GAP_PHY_2MBPS,
.rx_phys = BLE_GAP_PHY_2MBPS
opt.common_opt.conn_evt_ext.enable = 1;

TX Buffer size increased to 32 has very high effect on speed(couldn't set more because of memory error but I believe we can fix this problem)

The BT adapter

you can see more information <<here>>

RE: nRF Connect for Desktop max throughput

mhassan@thoughttechnology.com — Sat, 09 Apr 2022 21:05:02 GMT

I don't know about nRF Connect desktop test, but by using windows device in C# I could achieve 800K throughput , and the optimized connection interval in my case is 30ms, maybe windows only accept (specific number of packet each interval because in theory longer interval should result less overhead of interval event itself).

ATT MTU size: 247
Connection interval: 30ms
Data length ext: i'm not sure
Connection length ext: on
Preferred PHY: 2 Mbps

TX Buffer size increased to 32 has very high effect on speed(couldn't set more because of memory error but I believe we can fix this problem)

RE: nRF Connect for Desktop max throughput

lammobile — Tue, 18 Jan 2022 03:36:26 GMT

Hi Kenneth,

Please let me know, does the latest version support 2M phy for serial port?

Info:

nRF Connect for Desktop v3.9.3

Bluetooth Low Energy v3.0.0

Best regards,
Lam

RE: nRF Connect for Desktop max throughput

Kenneth — Tue, 21 Aug 2018 15:16:44 GMT

Hi Marten,

Don't have any max throughput numbers with nRF Connect no. But presuming they can achieve 1 packet (247byte) in each connection interval, then the throughput with 7.5ms interval will be approx: 263kbps, while 50ms will be approx 40kbps.

Best regards,
Kenneth

RE: nRF Connect for Desktop max throughput

Marten — Tue, 21 Aug 2018 13:39:31 GMT

Hi Kenneth,

Thanks for the answer. I will modify the ble_app_att_mtu_throughput central part to test the max throughput of my peripheral device instead of using nRF Connect.

Any idea what the max throughput is with nRF Connect ? It seems like ~250Kbps is the max. Is it somewhere documented ? Also the 1Mbps limit is not mentioned in the documentation I believe.

Regards,

Marten

RE: nRF Connect for Desktop max throughput

Kenneth — Mon, 20 Aug 2018 08:54:34 GMT

Hi Marten,

It's unlikely that the nRF Connect for Desktop will be able to achieve high throughput. The short reason is due to the way all events and commands are ack'ed on the transport layer between the PC and the connectivity firmware on the nRF52. This cause delays that prevent high throughput.

I believe 2Mbps is planned later this autumn.

Best regards,
Kenneth