Toradex verdin IMX8MP-Dhalia I2C-3 operation issue

Technical Support
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1

Hi ,

I am trying to communicate between my verdin-dhalia to a battery using an I2C.Below are the configurations.

I am using dhalia secondary header pins 19(I²C_EXT_SDA) and 20(I²C_EXT_SCL). This is connected to I2C-3 port as per the reference manual.So below are the steps i am using to communicate.

file = open(“/dev/i2c-3”, O_RDWR); => file value is 19 after executing this line
rc = ioctl(file, I2C_SLAVE, addr); => rc value is 0 after execution, I2C_SLAVE is 0x0703 and addr is 0x16(battery address).
data = i2c_smbus_read_byte_data(file, reg); reg is 0x0e.This function call is below

args.read_write = 1;
args.command = reg;
args.size = 2;
args.data = data;
return ioctl(file,I2C_SMBUS,&args); //I2C_SMBUS is 0x0720.

this function returns an error.

need help in establishing the communication with the battery.

Regards
Vijay

2

Further update: Refer the below image.

image
image992×361 7.87 KB

I got these signals on the I2C data and clock lines. This is one set of command in the consequtive set of commands.below is the expected signal.

image
image1329×187 15.3 KB

Comparing the actual and expected signals, the problem currently i am facing is that i am not able to send I2C message continiously. I am able to just send one set of data/command Any help would be great.

3

Hi @VijayRichard,

In order to help you better with this scenario, I have some questions:

  • Which error are you seeing? Can you share it with us?
  • Can you send me the output of ls -l /dev/verdin-i2c* please?
  • Which OS are you using? Torizon, BSP, custom Yocto image…

Also please check our guide about I²C and Linux here: I2C (Linux) | Toradex Developer Center

Best regards,
Hiago.

4

Hi Hiago,

I am Subbu. Vijay is my colleague. I am currently looking into this issue. We have revised our board schematics. Currently I dont see the battery (0x16) on any of the i2cs. Attached is the terminal output and the devicetree source. We have a custom build image.

5

Hi @Subbu,

There is no file attached to your message that I can see. Can you please upload it on share.toradex.com and send me the link so I can download it?

Best Regards,
Hiago.