ble and peripheral interfaces (such as spim and twim) run at the same time, causing serious packet loss of transparent ble data

RE: ble and peripheral interfaces (such as spim and twim) run at the same time, causing serious packet loss of transparent ble data

Jørgen Holmefjord — Wed, 12 Jul 2023 14:02:29 GMT

Hi,

Can you elaborate on what data loss you are seeing?

Is the data loss happening over BLE or over SPI?

Is the BLE link configured to handle the amount of data you are sending? 256 packets a second at 200byte per packet requires multiple packets to be sent each connection interval.

Can you provide a sniffer trace of the on-air BLE activity?

Best regards,
Jørgen

RE: ble and peripheral interfaces (such as spim and twim) run at the same time, causing serious packet loss of transparent ble data

hananddong — Wed, 12 Jul 2023 09:10:32 GMT

Hi Ketiljo；

The red mark is the spi pin I used in the figure above, and the speed of the spi is set to 8Mhz. pins marked "Standard drive, low frequency I/O only" is not used for high speed in my code.

My main problem is sending too much data using ble and then using too much cpu resources in loop (without rtos). Although the asynchronous spi (spi with easydma -> spim) is used, it still causes serious packet loss when sending data using ble.

Since I don't know much about the internal mechanism of the softdevice, I want to know what is the root cause of ble packet loss? For example, due to the large amount of data, there is less opportunity to resend data in the softdevice, and then a large number of spi calls occupy the time of data sending in the softdevie？

RE: ble and peripheral interfaces (such as spim and twim) run at the same time, causing serious packet loss of transparent ble data

ketiljo — Tue, 11 Jul 2023 12:31:24 GMT

What pins do you have the SPI connected to? Only pins not marked "Standard drive, low frequency I/O only" can be used for SPI when the radio is use. See https://infocenter.nordicsemi.com/topic/ps_nrf52840/pin.html#aqfn73