Data Pass-through Channel Service

Integration of standard Bluetooth Low Energy (LE) protocol provides data pass-through channel services for MCU and mobile app under Bluetooth LE connection. Thus, meet customized requirements and implement direct communication between the two parties.

Overview

Thanks to the generic Bluetooth module, the data pass-through channel service enables the MCU to directly establish a communication channel with the mobile app over Bluetooth, helping meet the varied development needs of the MCU.

Scenarios:

• Complex protocol interaction scenarios where direct communication with the mobile app or panel is required.
• Scenarios that require coordination with custom panel logic.
• Certain services that are specific to a line of business.

Applicable firmware: Currently, only BF6H Bluetooth LE generic firmware supports this service, and other firmware will be available soon.

Related protocols

Enable/disable data pass-through channel (0xC400)

• This channel is disabled by default. When a product needs to use this channel, you can run the command to enable it. This channel supports transparent transmission of data reporting and sending. The module does not process specific data, but directly transmits the raw data to the app for processing.
• After enabling the mobile message notification feature, for the iOS scenario, the module will automatically initiate a request for pairing over Bluetooth and request to enable notifications after the module establishes a connection with the Tuya app. Users also need to authorize notifications on their iOS devices to ensure system messages can be properly sent to the MCU through the pass-through channel.
• An error will be returned if the data pass-through channel is used before it is enabled.
• When the device is unbound or reset locally, this setting will return to the default disabled state.

MCU -> module:

Description of config:

• Bit 0: Enable/disable the channel. A value of 0 means it is disabled, and a value of 1 means it is enabled.
• Bit 1: Enable/disable the mobile message notification feature. A value of 0 means it is disabled, and a value of 1 means it is enabled.
• Bit 2 to bit 7: reserved. Set the values to 0.

Module -> MCU:

Transmit data through the pass-through channel (0xC401)

This channel supports two-way data transparent transmission. The module does not process specific data, but directly transmits the raw data to the app for processing. Typically, this channel is used in conjunction with custom logic in a panel or app.

MCU <-> module:

Example

Here are some examples of implementation through the data pass-through channel service.

Message notification

When the mobile phone receives a message notification, the module will send the following data in the specified format through the data pass-through channel.

Example of message notification:

• WeChat: It’s really hot today

  55 AA 00 C4 00 0C 01 04 00 08 CA 4E 29 59 1F 77 ED 70 68

• Hang up calls (03 indicates hang up):

  55 AA 00 C4 00 05 01 01 00 01 03 CE

• Incoming call (01 indicates incoming call): 15000000000

  55 AA 00 C4 00 19 01 01 00 17 01 31 00 35 00 30 00 30 00 30 00 30 00 30 00 30 00 30 00 30 00 30 00 0C

FAQs

Q: In mobile message notification applications, what are the precautions in MCU programming?

A: Whenever the application layer receives the message notification switch DP data as ‘on’, both the pass-through channel and the mobile message notification service must be enabled through the pass-through channel switch (0xC400). For the iOS scenario, after receiving the command to turn on, the module will send a pairing request to the phone and request system notification permissions. Users need to confirm in the panel pop-up to use the message notification feature properly.

Additionally, when the device is unbound, users should follow the app’s pop-up prompts to unpair Bluetooth in the system Bluetooth settings. Otherwise, the device might experience connection issues.

Support and help

If you have any problems with TuyaOS development, you can post your questions in the Tuya Developer Forum.