i2c error,can't find the slave device

[david]

I configure the I2C/SPI board As master and talk to another slave device(TDCMX).But I can not find the slave device.
1.i2c scan
2 found 0 slave dev

However,I use TDCMX-PU as a master.It can communicate with the slave device normally.I want to know If there is some initialization with Sub-20 I missed.
Thanks in advance.

[serg]

Hi David,

If after the following steps

1) Check connection between devices - SDA/SCL/GND
2) turn on(plug) sub-20 & TDCMX
3) Launch the sub-20 tool application
4) Enter desired clock frequency into Freq(Hz) field(400000?) and press "Set" button
5) Press the "Scan" button

you see

Code: Select all

i2c set freq
i2c scan
found 0 slave dev

only an oscilloscope picture can clarify the problem. Do you know the i2c slave address of your TDCMX
If so enter this address in hex form into the "Slave Addr(hex)" field and try to read 1 byte from the device.

To do so, fill out the following fields:

Read Byte Count 1
Memory Address 0
Memory Address Size 0

and press the "Read" button

Capture the picture and send it to us

Thanks

[david]

I solved the problem.
When I use oscilloscope to debug.I found the reason.I missed the groud PIN on sub-20 to connect to TDCMX .
Thanks for your timely response.