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LIS3DH SPI 3/4 wire not work properly

Question asked by galkin.maxim.001 on Apr 1, 2013
Hello.
I use LIS3DH accelerometer with 4-wire SPI interface.
I attached schematic of accelerometer connection (AccelSch.pdf).
ACL_VDDIO = 3,3 V
ACL_VDD = 3,3 V
Other ACL signals connect to microcontroller pins.
R9A=R9B=R9C=R9D = 100 Ohm.
When I configured accelerometer to work in 4-wire mode I saw that accelerometer send data on SDI pin 6. (SPI_Data_Transfer_4wires_Mode_Img1.jpg and SPI_Data_Transfer_4wires_Mode_Img2.jpg).
Yellow signal - clock (SCL pin 4).
Green signal - SDI pin 6 on net ACL_SDA/SDI/SDIO.
When I configured accelerometer to work in 3-wire mode I saw that amplitude of signal on SDI pin 6 increased (SPI_Data_Transfer_3wires_Mode.jpg).
Why accelerometer send data in 4-wire mode?

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