Data sent limited when transmitting from nrf52810 to IOS phone

RE: Data sent limited when transmitting from nrf52810 to IOS phone

Simonr — Fri, 02 Oct 2020 07:03:18 GMT

Yes, the nRF52810 does support flow control for UART, so feel free to do so. You can see section 6.27 UART in the nRF52810 product specification for more information.

Best regards,

Simon

RE: Data sent limited when transmitting from nrf52810 to IOS phone

jerry — Thu, 01 Oct 2020 12:15:49 GMT

Simon,

Thank you. Does the nrf52810 support flow control? I'd rather use that then a fixed delay. The nrf52810 is in a module we purchase from Raytac, that uses AT commands. The module has hardware pins for flow control, but I did not tie them to the micro on our PCB board, so I would prefer XON,XOFF control. Is that function a part of the nrf52810 or is that a function of the Raytac program?

Thanks Again,

Jerry

RE: Data sent limited when transmitting from nrf52810 to IOS phone

Simonr — Thu, 01 Oct 2020 07:03:11 GMT

Hi again,

Yes, seeing as you will have to use two packets to transfer all the data either way, there shouldn't be an issue sending 128 bytes per packet.

Best regards,

Simon

RE: Data sent limited when transmitting from nrf52810 to IOS phone

jerry — Wed, 30 Sep 2020 12:19:59 GMT

Hi Simon,

Thanks for replying here. Since I need to transmit 256 bytes, 247 will not even be enough. Can I delay after sending say 128 bytes then send the remaining 128 bytes in a second packet. I can put in a delay between each. Will that work?

Thanks,

Jerry

RE: Data sent limited when transmitting from nrf52810 to IOS phone

Simonr — Wed, 30 Sep 2020 08:18:04 GMT

Hi Jerry

iOS has an "issue" with achieving 247 MTU, and this seems to be what is occurring in your case as well. Please check out this case, where this issue is discussed in detail. You can also find a few workarounds to the issue there. One of these workarounds are to delay the MTU request/negotiation to occur at a later point rather than directly after the connection. I also have this modified version of the ble_app_uart example which should allow IOS devices to achieve a 247 bytes if you are interested. Keep in mind though, that this example project has not been through thorough testing, so there might be some bugs present.

devzone.nordicsemi.com/.../6560.ble_5F00_app_5F00_uart-_2800_1_2900_.zip

My colleague Jimmy has also made a thorough blog post on maximizing BLE throughput with iOS available here if that's of any use to you.

Best regards,

Simon