通过RFCOMM蓝牙读取ELM327 OBD2原始数据时终端异常的问题求助

大家好，我现在在尝试用Lubuntu读取汽车的OBD2数据，用的是便宜的ELM327蓝牙连接器，但遇到了一个奇怪的问题——连接后终端异常，每次只能显示一个字符，而且收不到设备的响应，想请教下大家我哪里操作错了？

已完成的操作步骤 #

1. 蓝牙配对与信任 #

我先在蓝牙控制台完成了设备配对和信任操作，过程如下：

[bluetooth]# pair 00:10:CC:4F:36:03

Attempting to pair with 00:10:CC:4F:36:03

[CHG] Device 00:10:CC:4F:36:03 Connected: yes

Request PIN code

[agent] Enter PIN code: 1234

[CHG] Device 00:10:CC:4F:36:03 UUIDs: 00001101-0000-1000-8000-00805f9b34fb

[CHG] Device 00:10:CC:4F:36:03 ServicesResolved: yes

[CHG] Device 00:10:CC:4F:36:03 Paired: yes

Pairing successful

[CHG] Device 00:10:CC:4F:36:03 ServicesResolved: no

[CHG] Device 00:10:CC:4F:36:03 Connected: no

[CHG] Device 00:10:CC:4F:36:03 Connected: yes

[CHG] Device 00:10:CC:4F:36:03 Connected: no

...（中间重复的连接断开日志省略）

[bluetooth]# info 00:10:CC:4F:36:03

Device 00:10:CC:4F:36:03 (public)

Name: OBDII

Alias: OBDII

Paired: yes

Trusted: no

Blocked: no

Connected: no

LegacyPairing: no

UUID: Serial Port               (00001101-0000-1000-8000-00805f9b34fb)

ManufacturerData Key: 0x0100

ManufacturerData Value:

03 36 4f cc 10 00                                .6O...

ManufacturerData Key: 0x7262

ManufacturerData Value:

32 32 78 78 11 22 33 44 55 66 aa bb 00 00        22xx."3DUf....

RSSI: -54

[bluetooth]# trust 00:10:CC:4F:36:03

[CHG] Device 00:10:CC:4F:36:03 Trusted: yes

Changing 00:10:CC:4F:36:03 trust succeeded

2. 建立RFCOMM串口连接 #

我先用sdptool查到了设备的串口通道：

user@user-20n20009pg:~$ sdptool records 00:10:CC:4F:36:03

Service Name: JL_SPP

Service RecHandle: 0x10004

Service Class ID List:

"Serial Port" (0x1101)

Protocol Descriptor List:

"L2CAP" (0x0100)

"RFCOMM" (0x0003)

Channel: 2

Profile Descriptor List:

"Serial Port" (0x1101)

Version: 0x0102

然后用rfcomm建立连接：

user@user-20n20009pg:~$ sudo rfcomm connect /dev/rfcomm0 00:10:CC:4F:36:03 2 &

[1] 1583

user@user-20n20009pg:~$ Connected /dev/rfcomm0 to 00:10:CC:4F:36:03 on channel 2

Press CTRL-C for hangup

遇到的问题 #

当我用screen连接到这个串口时，终端出现异常：

user@user-20n20009pg:~$ sudo screen /dev/rfcomm0 38400

打开新终端后，我输入命令（比如ATZ）时，每次只能显示一个字符（比如只显示>a），根本没法完整输入命令，而且也收不到ELM327的任何响应。

我已经试过更换波特率，比如9600、38400、115200，但问题依然存在。有没有朋友知道我哪里漏了什么步骤？

备注：内容来源于stack exchange，提问作者sgt