DSPC01

Revision 1.21

Page

of 8

April. 2014

5

bits will be divided by 10 and the result is the actual temperature in Celsius degree.

Command

Function

Returned Value

Explanation

80

Read temp value

0x XX XX

Signed value; one decimal fraction

Table 8 DSPC01 Temperature Mode

7.

Communication

DSPC01 communicates with the host through I2C interface so three wires are needed for

normal operation. The address for “write operation” is 0x20 and for “read operation” it is

0x21. Because the pull-up resisters are installed on the DSPC01 module, the host doesn’t need

any pull-up for I2C interface.

TECHNICAL NOTES

1.

The timing for “Start”, “Stop”, “ACK”, “NACK”, “write” and “read” is same as I2C

2.

The timing for write is : start + write 0x20 +ACK + write command + ACK + stop

3.

The timing for read is : start + write 0x21 + ACK + read data1 + ACK + read data2+ ACK

+…read datax+ NACK + stop

4.

For compass calibration, it will last for around 9.5s, during this period, it won’t respond for

any command.

5.

For any command, if you don’t get the ACK from the module, you must add the timeout (0.1s)

in your program. And resend this command again till you got the right ACK.

6.

When switching the write command to read command you need to wait 150ms and 10ms for

switching from read to write.

7.

When you want the module to be in power save mode, you need to send the write command

(0x71)

8.

When wake up from sleep mode, you need to send write command (0x70), and also any

commands except 0x71 will wake up the module.

9.

For the frequency of I2C, it can’t be higher than 10 KHz. For old version of sensor, the

highest frequency can’t exceed 5 KHz so users can try to start at 5 KHz or lower.

10. For the power supply it is limited to ( 2.4 – 3.6V)

11. For data reading, the highest byte is first and MSB in each byte. For example

Start + 0x20 + ack + 0xa0 + ack + stop

Delay 200ms

Start + 0x21 + ack + 0x00 + ack + 0x03 + ack + 0x48+ NACK + stop

The altitude got is 0x000348, and it is 84.0m