NEED HELP: How to register SPI and I2C devices under L4T (kernel 3.10.40)

Hello,

I know only the command ‘echo " " > /sys/bus/…’

Is there any other way?
As parameter for kernel or for kernel module(s)!

I use a RTC module (DS3231) and a temperature/pressure sensor (bmp180) connected via I2C to Jetson TK1. I placed the “echo” command in ‘/etc/rc.local’ but looking for other ways!

BTW: these modules are usable/available, but the command ‘i2cdetect -y 1’ doesn’t see them! Any idea, why?

Kind Regards,
Michael

Hi. So this two devices is 3.3 volts tolerance. The Jetson I2C-1 bus already haves pull-ups resistors. If you use DS3231 and bmp180 assembled on PCB modules, these modules also can have i2c-bus pull-ups resistors and that can cause an i2c issue. If yes, simply desolder pull-up resistors from DS3231 and bmp180 modules boards.
If you luck in " ls /dev", in this directory must be present 6 i2c buses “i2c-0, i2c-1…”. If this files is missing, you need to reconfigure and reflash the kernel.

Here’s an article on how to use the DS3231 on the Jetson to get started:

You will need a kernel module in order to configure it correctly. I haven’t used a bmp180, but would guess that the procedure is much the same.

Hello,

As I already wrote, the hardware modules and their drivers work fine (I wrote my own iio driver for the pressure sensor bmp180), but I’m searching for a way to start them without the ‘echo’ command. For example as parameters 'i2c_bus=1 addr=0x0068" to the module “rtc_ds3232”, if the driver is compiled as module or as parameters to the kernel.

Kind Regards
Michael