Changing the transmission power on ble_app_att_mtu_throughput example

Question

Hi, 
 I have searched Devzone for changing the transmission power; even though there were similar issues related to mine but at the end, It did not help me. 
 I am evaluating the new PHYs of BLE 5 in an indoor environment at the university. 
 I tried to use the following codes: 
 ret_code_t err_code = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_SCAN_INIT, BLE_CONN_HANDLE_INVALID, RADIO_TX_POWER); ( inside scan_start function) 
 err_code = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_CONN, BLE_CONN_HANDLE_INVALID, RADIO_TX_POWER); ( I used this one inside 
 ble_evt_handler function under BLE_GAP_EVT_CONNECTED.) 
 err_code = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_ADV, m_adv_handle, RADIO_TX_POWER); (I used this one inside advertising_start function) 
 
 I get fatal error!! 
 I know there is a long range example but I really want to use the throughput example with modified transmission power. 
 I do not know in which part I am doing wrong!!! Any help will be appreciated. 
 
 Br, 
 Ben

Ben · Answer

Hi, 
 I resolved the issue by changing: 
 " 
 case BLE_GAP_EVT_CONNECTED: err_code = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_CONN, BLE_CONN_HANDLE_INVALID, RADIO_TX_POWER); on_ble_gap_evt_connected(p_gap_evt); break; 
 " 
 to 
 " 
 case BLE_GAP_EVT_CONNECTED: m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle; err_code = sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_CONN, m_conn_handle, RADIO_TX_POWER); APP_ERROR_CHECK(err_code); 
 on_ble_gap_evt_connected(p_gap_evt); break; 
 " 
 The problem was in passing the correct connection handle to " sd_ble_gap_tx_power_set" function in connection state. 
 
 Br, 
 Ben