Re: [Paparazzi-devel] AspirinIMU SPI Voltage issue

[Jonathan Clapson]

My issue was caused by the barometer also trying to drive the miso pin. This is fixed by holding baro_cs at 3.3V

On Mon, Jul 22, 2013 at 10:59 AM, Jonathan Clapson <address@hidden> wrote:

Hey

I've been trying to get the aspirinIMU working via spi on the Raspberry Pi. I've been following the SPI code for the device on the paparazzi github. I've sent all the MPU6000 initialisation commands and verified them with oscilliscope, logic high is 3.3V logic low is ~0V. I then issued a read over SPI of the 'whoami' register. The MISO line does send the value back, but logic high is 3.3V and logic low is 1.8V. I am completely unsure about what is doing this. My current code is on github here: https://github.com/jonathan-clapson/AspirinIMUmodule

Lines 448 through 450 have been tested and produce the same results if they are included. 

Pin configuration

I've wired the 6.5V power supply pin into the RPI 5V supply, I have tried this on a seperate 6.5V supply as well producing the same results. 

SPI wires are wired directly from AspirinIMU to RPi SPI connections. 

If anyone has any idea's whats going on, or idea's what I should be looking into to fix this they are greatly appreciated. I'm really not sure whats going on with this.

Thanks

Jonathan Clapson