gatt client连接ELM327车载OBD芯片，初始化接收乱码如何解决？

gatt client，连接ELM327车载OBD芯片，初始化接收乱码。ATZ,Ati等是初始化指令，发送后会首先返回，紧接着是应答值，乱码如下所示，请教一下如何解决？
I (3027) GATTC_DEMO: connect to the remote device.
I (3037) GATTC_DEMO: stop scan successfully
I (3087) GATTC_DEMO: ESP_GATTC_CONNECT_EVT conn_id 0, if 3
I (3087) GATTC_DEMO: REMOTE BDA:
I (3097) GATTC_DEMO: 00 1d a5 68 98 8b
I (3097) GATTC_DEMO: open success
I (3387) GATTC_DEMO: discover service complete conn_id 0
I (3397) GATTC_DEMO: SEARCH RES: conn_id = 0 is primary service 1
I (3397) GATTC_DEMO: start handle 18 end handle 65535 current handle value 18
I (3407) GATTC_DEMO: service found
I (3407) GATTC_DEMO: UUID16: fff0
I (3407) GATTC_DEMO: Get service information from remote device
I (3417) GATTC_DEMO: ESP_GATTC_SEARCH_CMPL_EVT
I (3427) GATTC_DEMO: ESP_GATTC_CFG_MTU_EVT, Status 0, MTU 23, conn_id 0
I (3427) GATTC_DEMO: ESP_GATTC_REG_FOR_NOTIFY_EVT
I (3457) GATTC_DEMO: write char success
I (3467) GATTC_DEMO: ESP_GATTC_NOTIFY_EVT, receive notify value:
� (3467) GATTC_DEMO: atz
I (3557) GATTC_DEMO: update connection params status = 0, min_int = 8, max_int = 16,conn_int = 16,latency = 0, timeout = 300
I (4267) GATTC_DEMO: ESP_GATTC_NOTIFY_EVT, receive notify value:
>LM327 v1.5TTC_DEMO:
I (5447) GATTC_DEMO: write char success
I (5467) GATTC_DEMO: ESP_GATTC_NOTIFY_EVT, receive notify value:
I (5467) GATTC_DEMO: at@1
I (5467) GATTC_DEMO: ���?
I (7447) GATTC_DEMO: write char success
I (7467) GATTC_DEMO: ESP_GATTC_NOTIFY_EVT, receive notify value:
ELM327 v1.5TTC_DEMO: ati
>��7467) GATTC_DEMO:
I (7467) GATTC_DEMO: ESP_GATTC_NOTIFY_EVT, receive notify value:
I (7477) GATTC_DEMO: ��?
I (9447) GATTC_DEMO: write char success
I (9467) GATTC_DEMO: ESP_GATTC_NOTIFY_EVT, receive notify value:
I (9467) GATTC_DEMO: attp
I (9467) GATTC_DEMO: ���?
I (11447) GATTC_DEMO: write char success
I (11467) GATTC_DEMO: ESP_GATTC_NOTIFY_EVT, receive notify value:
I (11467) GATTC_DEMO: 0100
I (11467) GATTC_DEMO: ���?