diff --git a/android/hal-ipc-api.txt b/android/hal-ipc-api.txt
index a6d23dd..5349c53 100644
--- a/android/hal-ipc-api.txt
+++ b/android/hal-ipc-api.txt
In case of an error, the error response will be returned.
Opcode 0x0c - Read Characteristic command/response
+
+ Command parameters: Connection ID (4 octets)
+ Service ID (18 octets)
+ GATT ID (17 octets)
+ Authorization (4 octets)
+ Valid Service ID: as described in Get Included Service
+ Valid GATT ID: as described in Get Included Service
+ Response parameters: <none>
+
+ In case of an error, the error response will be returned.
+
Opcode 0x0d - Write Characteristic command/response
Opcode 0x0e - Read Descriptor command/response
Opcode 0x0f - Write Descriptor command/response
diff --git a/android/hal-msg.h b/android/hal-msg.h
index e0cee6f..dff4b0a 100644
--- a/android/hal-msg.h
+++ b/android/hal-msg.h
struct hal_gatt_gatt_id gatt_id[0];
} __attribute__((packed));
+#define HAL_OP_GATT_CLIENT_READ_CHARACTERISTIC 0x0c
+struct hal_cmd_gatt_client_read_characteristic {
+ int32_t conn_id;
+ struct hal_gatt_srvc_id srvc_id;
+ struct hal_gatt_gatt_id gatt_id;
+ int32_t auth_req;
+} __attribute__((packed));
+
/* Notifications and confirmations */
#define HAL_POWER_OFF 0x00