Bluetooth I2C Bus Adapterâ¢
Bluetooth I2C Bus Adapterâ¢
Bluetooth I2C Bus Adapterâ¢
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12<br />
MSB LSB<br />
ACK: 0xA8<br />
NAK: 0xA9<br />
Data<br />
Length<br />
The returned 1 byte tag value has 1 the byte same value 1 byte as the tag in 1 the byte request. The “Data Length”<br />
byte is 1 for a tag response.<br />
2.3.5 Combined Requests<br />
Tag Value Stop:<br />
Instead of transmitting a separate e.g. write or read request it is possible to combine<br />
different packets into one packet over air. The <strong>Bluetooth</strong> <strong>I2C</strong> <strong>Bus</strong> Adapter will perform<br />
repeated read and write operations on the <strong>I2C</strong> bus for a combined read/write request.<br />
To create combined requests the stop byte of the previous packet is left out and instead the<br />
start byte of the next packet acts as both the stop byte and start byte. It is only the last<br />
request in a combined request that has a stop byte.<br />
For example, assume that a combined request with a tag, <strong>I2C</strong> write, <strong>I2C</strong> read, and time<br />
request shall be created. It then looks like.<br />
Tag:<br />
MSB<br />
0xA5<br />
Tag Value<br />
1 byte 1 byte<br />
Write:<br />
0xA1<br />
<strong>I2C</strong> Slave<br />
Address<br />
The response to the above combined packet will be.<br />
ACK: 0xA8<br />
NAK: 0xA9<br />
Read:<br />
0xA2<br />
0xA3<br />
Data<br />
Length<br />
1 byte 1 byte 1 byte<br />
<strong>I2C</strong> Slave<br />
Address<br />
Data<br />
Length<br />
1 byte 1 byte 1 byte<br />
Data<br />
Length<br />
Tag<br />
Value<br />
Time:<br />
0xA4<br />
1 byte<br />
Data<br />
LSB<br />
Stop:<br />
0xA3<br />
Stop:<br />
1 byte<br />
MSB LSB<br />
Read<br />
Data<br />
Time<br />
0xA3<br />
1 byte 1 byte 1 byte ”Data 4 bytes<br />
1 byte<br />
Length”<br />
from read<br />
packet
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