Tx Power using SoftDevices S140 nrf52840

RE: Tx Power using SoftDevices S140 nrf52840

TigerD — Tue, 10 Mar 2020 17:16:19 GMT

I changed my program to use ble_advertising_start() to advertise. That solves my problem, because it has valid handle to set tx power.

Thank You,

David

RE: Tx Power using SoftDevices S140 nrf52840

haakonsh — Tue, 10 Mar 2020 14:39:30 GMT

An error 12292dec corresponds with 0x3004. From the sd_ble_gap_tx_power_set API this is an BLE_ERROR_INVALID_ADV_HANDLE.

The API docs for the 'handle' parameter' says:
If role is BLE_GAP_TX_POWER_ROLE_ADV, the advertising set identified with the advertising handle, will use the specified transmit power, and include it in the advertising packet headers if ble_gap_adv_properties_t::include_tx_power set.

I guess you've defined an advertising set when you set the advertisement data, you need to use this handle with sd_ble_gap_tx_power_set.

RE: Tx Power using SoftDevices S140 nrf52840

TigerD — Tue, 10 Mar 2020 13:10:02 GMT

It is the same error 12292 from

err_code = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_ADV, BLE_GAP_ADV_SET_HANDLE_NOT_SET, 8 )

BLE_CONN_HANDLE_INVALID is defined as 0xFF

BLE_GAP_ADV_SET_HANDLE_NOT_SET is defined as 0xFFFF

I guess there is no essential difference.

Thanks,

David

RE: Tx Power using SoftDevices S140 nrf52840

haakonsh — Tue, 10 Mar 2020 13:04:50 GMT

Sorry I meant to use BLE_GAP_ADV_SET_HANDLE_NOT_SET as the connection handle.

RE: Tx Power using SoftDevices S140 nrf52840

TigerD — Mon, 09 Mar 2020 13:53:01 GMT

I did. The call sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_ADV, BLE_CONN_HANDLE_INVALID, -20 ), is before start advertisements.

It generates 12292 run-time error.

David

RE: Tx Power using SoftDevices S140 nrf52840

haakonsh — Mon, 09 Mar 2020 13:50:09 GMT

Have you tried calling sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_ADV, BLE_CONN_HANDLE_INVALID, -20 ) before you start advertiments?

RE: Tx Power using SoftDevices S140 nrf52840

TigerD — Mon, 09 Mar 2020 13:42:19 GMT

Hi Haakonsh,

My program is based on

..\nRF5_SDK_15.3.0_59ac345\examples\ble_peripheral\ble_app_beacon

and using softDevice call to Advertise:

err_code = sd_ble_gap_adv_start(m_adv_handle, APP_BLE_CONN_CFG_TAG);

The call to set TX POWER with BLE_GAP_TX_POWER_ROLE_SCAN_INIT

err_code = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_SCAN_INIT, BLE_CONN_HANDLE_INVALID, -20 );

doesn't change the TX power for Advertising ( it is easily testable, e.g. using Android phone, it always reports the same RSSI from the unit, no matter what setting of the tx_power ( int the above case, it is -20).

( I also tested with Proximity example, which is BLE API based, change tx power with BLE_GAP_TX_POWER_ROLE_ADV, will change the rssi from -50dBm to -100dBm, with 8 and -40 tx power settings respectively.)

But if the call set TX POWER with BLE_GAP_TX_POWER_ROLE_ADV

err_code = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_ADV, BLE_CONN_HANDLE_INVALID, -20 );

The program generates run-time error with error code : 12292

Thank You

David

RE: Tx Power using SoftDevices S140 nrf52840

haakonsh — Mon, 09 Mar 2020 13:27:27 GMT

That looks like the correct API usage to me.

"It seems that tx power is set not."
How do you know? Can you share any measurements with us?