BLE_GATT_OP_WRITE_CMD vs. BLE_GATT_OP_WRITE_REQ with indications

[John]

I'm working on a BLE central based on the Nordic UART Central example.  The peripheral I'm talking to has a characteristic that sends an indication when written to.  I'm writing to the characteristic with sd_ble_gattc_write().  I was originally using "write_op = BLE_GATT_OP_WRITE_CMD" in the write_params_t, but this triggered an error on the peripheral (which is also an nRF device).  But when I changed write_op to BLE_GATT_OP_WRITE_REQ (write with response), it worked fine and I got the expected indication in the on_hvx handler.

Unfortunately, I don't have visibility into the error on the peripheral, I only know that it's detecting an error in the BLE stack.

Is BLE_GATT_OP_WRITE_CMD not appropriate in this situation, or does it imply an issue with the peripheral?

Using nRF52832 with SDK 15.2.0, s132.

[Amanda Hsieh]

Hi, 

Please kindly provide logs on centra and peripheral. You could enable log in sdk_config.h as

// <h> nRF_Log 

//==========================================================
// <e> NRF_LOG_BACKEND_RTT_ENABLED - nrf_log_backend_rtt - Log RTT backend
//==========================================================
#ifndef NRF_LOG_BACKEND_RTT_ENABLED
#define NRF_LOG_BACKEND_RTT_ENABLED 1

// <e> NRF_LOG_ENABLED - nrf_log - Logger
//==========================================================
#ifndef NRF_LOG_ENABLED
#define NRF_LOG_ENABLED  1
#endif

-Amanda H