NRF_SDH_BLE_GAP_EVENT_LENGTH

[Lee Daniel Crocker]

Using SDK14.2.

I'm trying to optimize the throughput of my ble_nus-based app (I'm getting about 5k/sec right now). I've read elsewhere on this forum that increasing NRF_SDH_BLE_GAP_EVENT_LENGTH from the default of 3 to 16 might help, and I also read that doing so requires increasing ram_start. I updated sdk_config.h, and the changed the RAM address in the linker script from 20002076 to 20002800, but I continue to get error 4 from nrf_sdh_ble_enable(). Is there some other setting that needs to be tweaked at the same time? Did I not change the ram start enough? Any other suggestions?

[Håkon Alseth]

Hi,

 

Sorry for misunderstanding.

I suspect that your sdk_config has the "info" level set, and not the "debug" level for nrf_log.

You can set this in sdk_config.h:

#define NRF_SDH_BLE_LOG_LEVEL 4

and to set it to this level by-default:

#define NRF_LOG_DEFAULT_LEVEL 4

 

When setting it to print at a debug level, it outputs:

<debug> nrf_sdh: State request: 0x00000000
<debug> nrf_sdh: Notify observer 0x0003BBE4 => ready
<debug> nrf_sdh: State change: 0x00000000
<debug> nrf_sdh: State change: 0x00000001
<debug> nrf_sdh_ble: RAM starts at 0x20002B90
<debug> nrf_sdh_ble: RAM start location can be adjusted to 0x20002B88.
<debug> nrf_sdh_ble: RAM size for application can be adjusted to 0xD478.
<info> app: Heart Rate Sensor example started.
<info> app: Fast advertising.

 

Did your overall transfer rate change when trying 7.5 ms connection interval?

 

Cheers,

Håkon

[Lee Daniel Crocker]

I wasn't using logging at all--I had it turned off and not even linked in. I was looking at the variables directly with GDB after setting a breakpoint, and they did not show memory usage. But I see my mistake now--the value is only set after the enable() call.