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“BCA_Lib” is a library, which uses with BC-ANT-USB. This library makes the configuration of ANT communication simple. For more information of ANT protocol, please look at ANT's community page, “thisisant.com.” The details of BC-ANT-USB is listed on ANT/BC-ANT-USB of BC::labs.
The class reference of BCA_lib is published on this page.
The major features of this library are listed below.
The features of API are
[Caution]
To use this library, 5 files listed below and the driver for BC-ANT-USB are required.
[Transmitting side]
Channel Number: 0
Channel Type: 0 (MASTER)
Shared Channel: 0
Device Number: 33
Device Type: 1
Transmission Type: 1
Frequency: 66 (2466MHz: Since 2466-2400 =66)
Channel Period; 4Hz
Example code (transmitting data): this uses the callback interface.
[Receiving side]
Channel Number: 0
Channel Type: 0 (MASTER)
Shared Channel: 0
Device Number: 33
Device Type: 1
Transmission Type: 0 (Wildcard)
Frequency: 66 (2466MHz: Since 2466-2400 =66)
Channel Period: 4Hz
Example code (receiving data)
[Transmitting#1]
Channel Number: 0
Channel Type: 0 (MASTER)
Device Number: 1234
Frequency: 66 (2466MHz: Since 2466-2400 =66)
Channel Period: 4Hz
[Transmitting#2]
Channel Number: 0
Channel Type: 0 (MASTER)
Device Number: 5678
Frequency: 66 (2466MHz: Since 2466-2400 =66)
Channel Period: 4Hz
[Receiving]
Channel Number: 0
Channel Type: 1 (SLAVE)
Device Number: 0
Frequency: 66 (2466MHz: Since 2466-2400 =66)
Channel Period: 4Hz
Example Code
The registered (BCA_RegisterPairingFunc()) callback function is executed after the pairing process (BCA_STARTPairing()) has been executed and the selected duration of time has passed. The channel information, such as Device ID, of a newly found device is handed over to the function.
As the device, which you like to connect, is selected from the application of UI, the channel is opened (BCA_OpenChannel()).
The device search is performed by all 8 channels, so 8 devices would be found at most.
The common connection types of ANT network are 1-to-1 or broadcast connection.
Excluding broadcast, as a master connects to multiple slaves, the master needs to connect to each slave, independently.
図１
Shard Channel is a way that a single master connects to multiple slaves in one channel.
In Shared Channel, specific shared addresses are configured to all slaves. To add a shared address to a slave, the address consumes 2 bytes, and the total amount of data, which can be sent in one transmission, is reduced to 6 bytes.
図2
An example of transmitting data
図3
To send data, which includes a specific shared address from a mater, a node, which corresponds to a specific shared address that each slave has sent to the master, receives the data.
As the nodes start receiving the data, the nodes send back data, whose first 2bytes include own shared addresses, in broadcast.
Notify shared addresses on a shared channel
Configuration of Node A
Channel Number: 0
Channel Type: BCA_CHANNEL_TYPE_MASTER
Shared Channel: BCA_CHANNEL_SHARED
Device Number: 33 (the serial number of node A)
Device Type: 3 (the device type of node A)
Transmission Type: 3 (2bytes of shared channel address)
Frequency: 66 (2466MHz: Since 2466-2400 =66)
Channel Period: 4Hz~
Configuration of Node B, C, and D
Channel Number: 0
Channel Type: BCA_CHANNEL_TYPE_SLAVE
Shared Channel: BCA_CHANNEL_SHARED
Device Number: 33 (the serial number of node A)
Device Type: 3 (the device type of node A)
Transmission Type: 3 (2bytes of shared channel address)
Frequency: 66 (2466MHz: Since 2466-2400 =66)
Channel Period: 4Hz~
As the slaves (node B, C, and D) has completed opening own channels, they add own shared addresses to the first 2bytes of the data and send back the data in broadcast. Since now on, slaves reply as sending back the data which includes shared addresses at its first 2 bytes. Otherwise, the information of the configured shared address is void.
There are sets of sample code for transmitting, receiving, and pairing (receiving only). One is for C++, and the other is for Python.
