Raspberry Pi 3 Freescale Xtrinic KITMMA955xLEVM

What you say is true. The kit is nice for playing with the chip from Windows, but NXP does not tell how it communicates with the kit. Possible options:

1. Take off sensor chip to use on GPIO pin. Since this looks like a SMT and small, not recommended.
2. Try Windows 10 IOT on Raspberry Pi 3. Problem although this approach works, I would guess the application will not run under IOT.
3. Find software to intercept USB communications while running the Windows application. This is like detective work and may yield results. Then you need to roll your own code to mimic this. Can you program in Python?

Clem

Thanks Clem for your prompt response.

I was hoping for a protocol document, this is going to be much more difficult.

I think I will run SensorToolBox on a PC with a USB monitor/analyser.

This should allow me to determine the protocol and to reverse engineer the software interface.

Yes I can program in Python. I've written serial interfaces before and they are never ease.

I'll post the results once I have made some progress.

Mike

I tried answering this earlier today, by replying via email.  Doesn't look like Element14 forwarded it back.

In any case...  I'm working on a similar problem.  According to various docs, the chip involved is controlled via I2C and the USB interface should be "transparent" to Linux.  What do you get when you run the following?

    i2cdetect -l   (<-- that's a lower-case "L")

    i2cdetect -y 0

    i2cdetect -y 1

- Tim

Tim,

i2cdetect -l

Nothing, just returns with no message

i2cdetect -y 0 and i2cdetect -y 1

Directory/file not found

Using my laptop I loaded a USB sniffer USBlyzer and tried the USB analyser in SharkWire, the former gave me the best results. Below is the USB property and a single message. I'm not sure this is getting me anywhere!

This is the USB property:

Device Descriptor FT232R USB
UART

Configuration Descriptor 1
Bus Powered, 90 mA

Here is an example of an individual message:

Configuration Descriptor 1
Bus Powered, 90 mA

These are headers only. What is needed is the data portions and matching them with the operations you perform. For instance, the datasheet has setting registers values for operations. I know one sets the measurements active and standby. Another may set delays. Another may set recording the data internally and later request dumps of that stored data. Matching this with the flows should show what is sent and returned as a response.

Clem

Mike,

I'm so far behind on my reading that I can't say for sure.  What I've gathered so far is that virtual serial port should automatically be created (ttyUSB0????), which you would open send/read I2C messages.  I'm currently working the RPi3 review but I have a USB-2-I2C dongle and will eventually get around to trying it (will hook a TEA5767 or RDA5807SP to it).

- Tim