asm330lhhxg1 "who_am_i" register is reading back 0x48. Should be 0x6.

[arifkhan]

Connected STEVAL_$MKI243AA board to a nucleo-g491re board using 4 wire spi interface. The spi bus is setup to run @ 146 Kbits/sec. Reading back bad data. 

WHO_AM_I is 0x48

PIN_CTRL is 0x3E

Not sure but seem like the device is power

[arifkhan]

Hello Andrew,

Why do you say that MISO is bad? At the start of the SPI cycle, the IMU will not drive this signal, and so the MISO line would be floating (which is what is being observed). in the second part of the SPI cycle, read data is clearly being driven back by the IMU i.e. 0x48 (which is the problem. It should be 0x6B). 

Thx.

Rgds.

[Andrew Neil]

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@arifkhan wrote:

Why do you say that MISO is bad? .

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Just look at it:

It's supposed to be a digital signal; ie, it should have just 2 clearly distinct levels - low and high.

Yours seems to have about five different levels !

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@arifkhan wrote:

At the start of the SPI cycle, the IMU will not drive this signal, and so the MISO line would be floating 

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Even so, it shouldn't be fluctuating like that - something looks very wrong!

Again, you still haven't shared schematics or code.

[arifkhan]

Here is the sketch of my setup. The two evals boards are jumpered as shown with 8" jumper wires.

Project was created with STM32CubeMX and then debugged in STM32CubeIDE ver 2.1.1

[arifkhan]

Hey Andrew,

Do you see anything in the code?

Rgds.

[Andrew Neil]

I composed this reply some time last week, but it doesn't seem to have got published.

Fortunately, the forum kept a draft:

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A good, clear photo of your actual setup would help.

Check connections very carefully - particularly Vdd & GND.

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@arifkhan wrote:

The two evals boards are jumpered as shown with 8" jumper wires.

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These are quite prone to poor connections.

As noted above, your MISO behaviour very much suggests poor connections.

I would strongly recommend one of the X-Nucleo-IKS adaptor boards ("shields") - which accommodate the 24-pin DIL pinout; eg,

X-NUCLEO-IKS5A1 - X-NUCLEO-IKS02A1 - X-NUCLEO-IKS4A1

These models are Obsolete, but still usable if you happen to have one:

X-NUCLEO-IKS01A3 - X-NUCLEO-IKS01A1

[Andrew Neil]

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@arifkhan wrote:

Do you see anything in the code?

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Looks more like a hardware problem to me.

See my "delayed" post ...