FMT1000 Datasheet, PDF (11/29 Pages) Fairchild Semiconductor – Motion Tracking Module with Output of Orientation, Inertial Motion Data and Magnetic Field

1.7.4 I²C
The FMT1000-series supports the I²C transport layer. The FMT1000-series module acts as an I²C Slave. The Master
is defined as the user of the FMT1000-series module.
The I²C slave address is determined by the ADD0, ADD1 and ADD2 pins. These pins are pulled-up internally so
when left unconnected the address selection defaults to ADD[0..2] = 111.
Table 3. List of I²C Addresses
I²C Address
ADD0
ADD1
ADD2
0x1D
0
0
0
0x1E
1
0
0
0x28
0
1
0
0x29
1
1
0
0x68
0
0
1
0x69
1
0
1
0x6A
0
1
1
0x6B (default)
1
1
1
Table 4. Implemented I²C Bus Protocol Features
Feature
Slave Requirement
FMT1000-Series
7-Bit Slave Address
Mandatory
Yes
10-Bit Slave Address
Optional
No
Acknowledge
Mandatory
Yes
Arbitration
Clock Stretching
N/A
Optional
N/A
Yes⁽⁴⁾
Device ID
Optional
No
General Call Address
Optional
No
Software Reset
Optional
No
START byte
N/A
N/A
START Condition
Mandatory
Yes
STOP Condition
Mandatory
Yes
Synchronization
N/A
N/A
Note:
4. The FMT1000-series module relies on the I²C clock stretching feature to overcome fluctuations in processing
time, the Master is required to support this feature
Reading from the module
Reading from the module should start by first writing an opcode that tells the module what the Master needs to read.
Based on the opcode the module will prepare the related data to be transmitted. The Master then can do an I²C read
transfer to retrieve the data. Starting the read transfer after the opcode write can also be done using a repeated start
condition as is shown in Figure 7.
It is up to the Master to determine how many bytes need to be read. The Master should use the PipeStatus (0x04)
opcode of the MTSSP protocol for this.
If the master reads more bytes than necessary the FMT1000-series will restart sending the requested data from the
beginning.
The following diagram shows a read message transfer using a repeated start:
Figure 7. Read Message Transfer using a Repeated Start (I²C)
© 2015 Fairchild Semiconductor Corporation
FMT1000-series • Rev. 1.0
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