# BX310X BT SPP service cannot transfer 0x00 binary data

**URL:** <https://forum.sierrawireless.com/t/bx310x-bt-spp-service-cannot-transfer-0x00-binary-data/27409>\
**Category:** WiFi and Bluetooth Modules\
**Tags:** debug\
**Created:** [July 7, 2022, 10:07pm UTC](https://forum.sierrawireless.com/t/bx310x-bt-spp-service-cannot-transfer-0x00-binary-data/27409 "2022-07-07T22:07:25Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![hzou](https://avatars.discourse-cdn.com/v4/letter/h/d78d45/32.png) [@hzou](https://forum.sierrawireless.com/u/hzou)\
**Post date:** [July 7, 2022, 10:07pm UTC](https://forum.sierrawireless.com/t/bx310x-bt-spp-service-cannot-transfer-0x00-binary-data/27409/1 "2022-07-07T22:07:25Z")

</div>

**Firmware version** : BX3105.2.6.3

When I am using the classic BT SPP service data mode, each time when the binary data (0x00) is transferred, the module will recognize it as end of transmission and stop transferring.

The process is listing below:

1. enable the BT module, start pairing and enable SPP connection, this is working good.
2. Input AT+SRSPPSTART = 1 , will start data mode, working good.
3. start transmitting. When Transmitting any binary data other than 0x00, it’s working good. But when it meets 0x00, it will stop transmitting.

e.x. : Desired transmit data : 55 AA **00** EE FF  
What observed from output: 55 AA

Any possible ways to solve it or it’s just a bug? Thank you.

---

<div class="post-metadata">

**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/jyijyi/32/4766_2.png) [@jyijyi](https://forum.sierrawireless.com/u/jyijyi)\
**Post date:** [July 7, 2022, 11:06pm UTC](https://forum.sierrawireless.com/t/bx310x-bt-spp-service-cannot-transfer-0x00-binary-data/27409/2 "2022-07-07T23:06:06Z")

</div>

this should be fixed in FW 2.7.3, you can have a try on that

---

<div class="post-metadata">

**Author:** ![hzou](https://avatars.discourse-cdn.com/v4/letter/h/d78d45/32.png) [@hzou](https://forum.sierrawireless.com/u/hzou)\
**Post date:** [July 8, 2022, 2:12am UTC](https://forum.sierrawireless.com/t/bx310x-bt-spp-service-cannot-transfer-0x00-binary-data/27409/3 "2022-07-08T02:12:04Z")

</div>

Thank you, after updating FW to 2.7.3 this issue is solved.