Send a BLE command to a device using 4 characteristics (IDFGH-13817)

[yanmartins]

Answers checklist.

• I have read the documentation ESP-IDF Programming Guide and the issue is not addressed there.
• I have updated my IDF branch (master or release) to the latest version and checked that the issue is present there.
• I have searched the issue tracker for a similar issue and not found a similar issue.

General issue report

Hello!

I'm using ESPIDF version 5.3.1 with a ESP32-S3.
I flash the ESP as a BLE client with the example gatt_client and adapted it to try make it compatible with the device.

This device has 4 characteristics:

1. UART Data TX Characteristics
   UUID: 00000002-0000-1000-8000-008025000000
   Type: uint8 array (20 bytes)
   Properties: Notify
   The Terminal I/O client uses the UART Data TX characteristic to receive UART data from the server (peripheral) via notifications.
   Terminal I/O Profile Client Implementation Guide

2. UART Data RX Characteristics
   UUID: 00000001-0000-1000-8000-008025000000
   Type: uint8 array (20 bytes)
   Properties: Write without response
   The Terminal I/O client uses the UART Data RX characteristic to write UART data to the server (peripheral).

3. UART Credits TX Characteristics
   UUID: 00000004-0000-1000-8000-008025000000
   Type: uint8 (1 byte)
   Properties: Indicate
   The Terminal I/O client uses the UART Credits TX characteristic to receive UART credits (0 - 255) from the server (peripheral) via indications.

4. UART Credits RX Characteristics
   UUID: 00000003-0000-1000-8000-008025000000
   Type: uint8 (1 byte)
   Properties: Write
   The Terminal I/O client uses the UART Credits RX characteristic to grant UART credits (0 - 255) to the server (peripheral).

Here is the file with my changes:
gattc_demo.txt (Yes, there are redundant parts, it is a test xD)

The flow is:

1. Active Indicate
2. Activate Notify
3. Use Write to set the UART credits size
4. Use Write without response to send a command

The log:

I (1164) GATTC_DEMO:  
I (1174) GATTC_DEMO:  
I (1174) GATTC_DEMO:  
W (1184) GATTC_DEMO: searched device device_name
W (1184) GATTC_DEMO: connect to the remote device.
I (1184) GATTC_DEMO: stop scan successfully
I (1184) GATTC_DEMO:  
I (1194) GATTC_DEMO:  
I (1194) GATTC_DEMO:  
I (1194) GATTC_DEMO:  
W (5264) GATTC_DEMO: EVENT: 40
I (5264) GATTC_DEMO: ESP_GATTC_CONNECT_EVT conn_id 0, if 3
I (5264) GATTC_DEMO: REMOTE BDA:
I (5274) GATTC_DEMO: 00 21 7e 70 fa e3 
W (5274) GATTC_DEMO: EVENT: 2
I (5274) GATTC_DEMO: open success
I (5364) GATTC_DEMO: packet length updated: rx = 162, tx = 162, status = 0
W (6294) GATTC_DEMO: EVENT: 46
I (6294) GATTC_DEMO: discover service complete conn_id 0
W (6294) GATTC_DEMO: EVENT: 7
I (6294) GATTC_DEMO: SEARCH RES: conn_id = 0 is primary service 1
I (6304) GATTC_DEMO: start handle 17 end handle 65535 current handle value 17
I (6304) GATTC_DEMO: service found
I (6314) GATTC_DEMO: UUID16: fefb
W (6314) GATTC_DEMO: EVENT: 6
I (6324) GATTC_DEMO: Get service information from remote device
I (6324) GATTC_DEMO: ESP_GATTC_SEARCH_CMPL_EVT
I (6334) GATTC_DEMO: count: 6
E (6334) GATTC_DEMO: ASK FOR REG WRITE
E (6344) GATTC_DEMO: ASK FOR REG WRITE_NR
E (6344) GATTC_DEMO: ASK FOR REG NOTIFY
E (6344) GATTC_DEMO: ASK FOR REG INDICATE
W (6354) GATTC_DEMO: EVENT: 18
I (6354) GATTC_DEMO: ESP_GATTC_CFG_MTU_EVT, Status 0, MTU 158, conn_id 0
W (6364) GATTC_DEMO: EVENT: 38
I (6364) GATTC_DEMO: ESP_GATTC_REG_FOR_NOTIFY_EVT
W (6374) GATTC_DEMO: EVENT: 38
I (6374) GATTC_DEMO: ESP_GATTC_REG_FOR_NOTIFY_EVT
W (6444) GATTC_DEMO: EVENT: 9
I (6444) GATTC_DEMO: write descr success 
W (6494) GATTC_DEMO: EVENT: 9
I (6494) GATTC_DEMO: write descr success 
W (6494) ***: WRITE
W (6494) ***: WRITE NR
E (6494) ---: msg_len: 18
W (6544) GATTC_DEMO: EVENT: 4
I (6544) GATTC_DEMO: write char success 
W (6544) GATTC_DEMO: EVENT: 4
I (6544) GATTC_DEMO: write char success 

I tested sending commands using nRF Connect app and the device performs the actions correctly.

What could I be doing wrong?