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AIROC™ Bluetooth Forum Discussions

AKORICHE
Level 1
50 sign-ins First solution authored 25 sign-ins
Level 1

Hello,

I am using the MESH KIT, I connected one card to an PC. I use terminal to communicate with the device. My application is sensor client and temperature sensor server. The PC is connected to the sensor client card. From WICED HCI UART Control Protocol and hci_control_api.h I send this command to get temperature : 19 65 16 00 00

I get the response from the two seonsors : 19 81 16 11 00 1F 00 CD 65 00 00 00 FE F7 6D 3D 56 21 4F
00 01 2E 19 81 16 11 00 24 00 CD 65 00 00 00 FE F7 6D 3D 56 21 4F 00 01
2E 

I Want to know what mean each bytes to parse it in my application. Could you provide me help ?

 

 

 

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1 Solution
VictorZ_46
Employee
5 comments on blog 25 sign-ins 250 likes received
Employee

The format of the WICED HCI frame is defined in the WICED HCI Control Protocol document which should be present in the MTB installation. First octet is Type = 0x19 followed by 2 octets of opcode, followed by 2 octet of length of the data. As WICED HCI interface is between your application running on the MCU and your application running on the chip, the Opcode and the Data are completely your decision. As long as the first byte is 0x19 and the length correctly identifies the end of the packet, the embedded application and the MCU will receive the data. SDK provides sample Windows implementation of the MCU (VS_ClientControl) and multiple embedded "clients". It might be easier to reuse defined format and opcodes.

If you want to change period between Sensor performing measurements, you can definitely do it in the application. Just start the timer when you want to wake up and do the measurements. If you want to change the period how the data is reported to the client, the spec mandates that you follow the configuration. The sensor is not flexible to report when it wants. The Configuration manager can specify the period, but it also can specify the fast cadence so that the sensor reports data more often, for example, if the value is above certain level the Status is sent more often. If you are implementing closed system and do not need to follow the spec exactly, you can indeed do what you want.

Remote Provisioning Protocol is implemented, tested and passed certification. Meanwhile, it is turned off in the release because the Mesh 1.1 specification has not been published yet. If you would like to evaluate the feature, please let us know and we can probably show you how to enable the feature under the condition that you cannot bring it to the market until Mesh 1.1 is published.

Yes, the accuracy of BLE clock is pretty bad (255ppm) and the time drift between two devices is expected. The way to synchronize the network is to use Time Model. Make sure that you add some randomization when sending data to avoid collision. 

Max Tx level for CYW20819 is 4dBm and Rx sensitivity is about -90 (please check exact number in the data sheet). In an open space two devices should be able to talk within 40-50 meters. There is a very similar device CYW20820, which is the same as 20819, but has internal Power Amplifier. It can transmit 10dBm (or maybe even 12, check the data sheet), so the distance should be 80-100meters. RF propagation indoors is a different subject and it is not possible to define distance for indoor scenarios. It depends on the size of the rooms, size of the doors, types of the walls, or even the type and the location of the installed furniture. 

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BragadeeshV
Moderator
Moderator First question asked 1000 replies posted 750 replies posted
Moderator

Hi @AKORICHE ,

Can you please let us know which kit you are using in your application? Also, can you please elaborate your setup? Are there two kits with one running sensor client and other running  temperature sensor server example?

Please let us know if you are using LE MESH application or is it a normal LE application? Also please let us know what this command does "19 65 16 00 00"? Please provide us references to this command.

Regards,
Bragadeesh
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AKORICHE
Level 1
50 sign-ins First solution authored 25 sign-ins
Level 1

Hi Bragadeesh ,

Thank you for answering my questions.

After exploring the different BLE mesh functions using the CYBT-213043-02 mesh kit. I got some questions.

The IDE used is ECLIPSE IDE MODUSTOOLBOX 2.3.
I follow the documentation of getting started with ble mesh.

Mainly, we will use the vendor model and the embedded provisionner.

The embedded provisionner will act as a Client. It will be controlled by a second MCU via HCI. The first question is there documentation of the HCI frame related to HCI mesh event ? The idea is to exchange information between the network and the second MCU via the client using HCI.

- I asked this question in another post but I didn't get the answer yet. Is-it possible to change the sleep time in the LPN mode while runing. For exemple, I will change the time from one measure each minute to one measure each 10 minutes and then get back to 1 minutes sleep ?

- Is the remote provisionning implemented ?

- Is there a way to synchronize all the nodes ? I mean they will all wake-up together and send their data at the same moment. Actually, while ruing an offset appears and it continues to increase at each communication.

What's the maximum distance between two modules in indoor ?

 

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VictorZ_46
Employee
5 comments on blog 25 sign-ins 250 likes received
Employee

The format of the WICED HCI frame is defined in the WICED HCI Control Protocol document which should be present in the MTB installation. First octet is Type = 0x19 followed by 2 octets of opcode, followed by 2 octet of length of the data. As WICED HCI interface is between your application running on the MCU and your application running on the chip, the Opcode and the Data are completely your decision. As long as the first byte is 0x19 and the length correctly identifies the end of the packet, the embedded application and the MCU will receive the data. SDK provides sample Windows implementation of the MCU (VS_ClientControl) and multiple embedded "clients". It might be easier to reuse defined format and opcodes.

If you want to change period between Sensor performing measurements, you can definitely do it in the application. Just start the timer when you want to wake up and do the measurements. If you want to change the period how the data is reported to the client, the spec mandates that you follow the configuration. The sensor is not flexible to report when it wants. The Configuration manager can specify the period, but it also can specify the fast cadence so that the sensor reports data more often, for example, if the value is above certain level the Status is sent more often. If you are implementing closed system and do not need to follow the spec exactly, you can indeed do what you want.

Remote Provisioning Protocol is implemented, tested and passed certification. Meanwhile, it is turned off in the release because the Mesh 1.1 specification has not been published yet. If you would like to evaluate the feature, please let us know and we can probably show you how to enable the feature under the condition that you cannot bring it to the market until Mesh 1.1 is published.

Yes, the accuracy of BLE clock is pretty bad (255ppm) and the time drift between two devices is expected. The way to synchronize the network is to use Time Model. Make sure that you add some randomization when sending data to avoid collision. 

Max Tx level for CYW20819 is 4dBm and Rx sensitivity is about -90 (please check exact number in the data sheet). In an open space two devices should be able to talk within 40-50 meters. There is a very similar device CYW20820, which is the same as 20819, but has internal Power Amplifier. It can transmit 10dBm (or maybe even 12, check the data sheet), so the distance should be 80-100meters. RF propagation indoors is a different subject and it is not possible to define distance for indoor scenarios. It depends on the size of the rooms, size of the doors, types of the walls, or even the type and the location of the installed furniture. 

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