Cannot Access Voltage and Current Monitors with Custom Pinmux

Related to this post that I made a while ago, I am having a similar problem where our pinmux settings seem to be preventing access to the voltage and current monitors on the Orin NX SOM.

I am trying to read the input voltage/current to the Orin NX SOM by accessing the file path
and reading the output of /curr1_input and /curr1_input /in1_input.

After using our custom pinmux, I can access the /sys/bus/i2c/drivers/ina3221 directory but I do not see the 1-0040 directory available.


Here is what we change in our pinmux:

Signal Name Changes Required
GPIO03 Output, Drive 1
GPIO06 Input, N/A
SPI1_CS0* Input, Int PD
SPI1_CS1* Input, Int PD
UART1_RXD Input, Int PD
GPIO12 Output, Drive 1
GPIO07 Output, Z
CAM1_PWDN Output, Z
GPIO09 Output, Z
GPIO01 Output, Z
GPIO04 Output, Drive 1
GPIO05 Output, Drive 0
CAM0_PWDN Output, Drive 0
I2S0_SCLK Input, Int PD
I2S0_DOUT Input, Int PD
I2S0_DIN Input, Int PU
I2S0_FS Input, Int PU
DP1_AUX_P unused_DP_AUX_CH0_P,Not Assigned
DP1_AUX_N unused_DP_AUX_CH0_N, Not Assigned
DP1_HPD unused_DP_AUX_CH0_HPD, Not Assigned
I2S1_SCLK Output,Drive 1
I2S1_DOUT Output, Drive 1

Which of these changes could cause this issue? Is there any way to get access to voltage/current monitoring once the system is fully booted? If we have an assigned use for these pins, do we have to re-assign the pins whenever we want to access the voltage/current monitor?

hello lphillips,

is the general i2c1 still available?
please also check i2c bus under c240000, for instance, /sys/devices/platform/c240000.i2c/i2c-1/1-0040

Hi @JerryChang

General i2c1 is still available on this device as far as I can tell.


hello lphillips

is the hardware monitor nodes available for checking voltage and current?
it should under… /sys/class/hwmon/

Hi @JerryChang,

I am able to access /sys/class/hwmon, where should the nodes for checking voltage and current be located? This is the result of trying to access /sys/class/hwmon:

Should there be an hwmon3 at this location?

it looks the the nodes for checking voltage and current has missing.
could you please narrow down which pinmux change you’ve done to cause INA3221 probing fail?

This is the question I am asking you @JerryChang, I have highlighted the changes I make to the pinmux in the first post. Do you know which settings could cause this issue?

hello lphillips,

this should not due to pinmux modification, we’ve follow the same pinmux settings but we cannot reproduce this locally.

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