We have done 2 carrier boards, the first one is OK but we have I2C and camera failures with the second one

Autonomous Machines Jetson & Embedded Systems Jetson Nano
1

Our goal is to stream video from one camera (IMX219) to the network.

We use our carriers boards with a Jetson Nano Production Module .

Below there is the schematic of our first carrier board named Jetson Nano Carrier rev A1:

Jetson Nano Carrier rev A1_b.pdf (322.0 KB)

We use the Jetson Linux R32.7.4 without any modification of the device tree.
In this configuration we are able to detect the camera and do the streaming job using gstreamer :)

Then we had to reduce the size of our carrier board, for that we deleted :

  • The hdmi port,
  • one camera port
  • and the i2c mux.

the result is in the schematic named: Jetson Nano Carrier rev A2 below :

Jetson Nano Carrier rev A2_c.pdf (211.0 KB)

Unfortunately, with this version the camera is not detectable, as well as our eeprom and our remote IO expander (PCA8574) :(

What could we have missed in our 2nd carrier board ?

Thank you in advance for your help.

Frédéric

3

I don’t see error on Jetson side. Did you probe the power on sequence? Is there any other device on carrier board could affect Jetson pin status during power on?

4

We have tested the power sequence, which is very simple. Carrier board powers are starting after deassertion of SYS_RESET#

Devices on the carrier board are very limited, the camera, an eeprom and an I2C GPIO expander.

The second carrier board is a reduction of the first one, we have removed HMDI and one camera, including the I2C multiplexing.

It seems that on the 2nd board there is some problems with I2C:

On the first board we are able to detect our eeprom and our I2C GPIO Expander :
image
and not on the second board.

However on the 2 boards we detect the jetson nano module eeprom:
image

Also I notice a difference in dmesg the kernel command lines are differents :

First board:
[ 0.000000] Kernel command line: tegraid=21.1.2.0.0 ddr_die=4096M@2048M section=512M memtype=0 vpr_resize usb_port_owner_info=0 lane_owner_info=0 emc_max_dvfs=0 touch_id=0@63 video=tegrafb no_console_suspend=1 console=ttyS0,115200n8 debug_uartport=lsport,4 earlyprintk=uart8250-32bit,0x70006000 maxcpus=4 usbcore.old_scheme_first=1 lp0_vec=0x1000@0xff780000 core_edp_mv=1125 core_edp_ma=4000 gpt earlycon=uart8250,mmio32,0x70006000 root=/dev/mmcblk0p1 rw rootwait rootfstype=ext4 console=ttyS0,115200n8 console=tty0 fbcon=map:0 net.ifnames=0 sdhci_tegra.en_boot_part_access=1 quiet root=/dev/mmcblk0p1 rw rootwait rootfstype=ext4 console=ttyS0,115200n8 console=tty0 fbcon=map:0 net.ifnames=0 sdhci_tegra.en_boot_part_access=1

and 2nd:

[ 0.000000] Kernel command line: tegraid=21.1.2.0.0 ddr_die=4096M@2048M section=512M memtype=0 vpr_resize usb_port_owner_info=0 lane_owner_info=0 emc_max_dvfs=0 touch_id=0@63 video=tegrafb no_console_suspend=1 console=ttyS0,115200n8 debug_uartport=lsport,4 earlyprintk=uart8250-32bit,0x70006000 maxcpus=4 usbcore.old_scheme_first=1 lp0_vec=0x1000@0xff780000 core_edp_mv=1125 core_edp_ma=4000 gpt tegra_fbmem=0x140000@0x92cb4000 is_hdmi_initialised=1 earlycon=uart8250,mmio32,0x70006000 root=/dev/mmcblk0p1 rw rootwait rootfstype=ext4 console=ttyS0,115200n8 console=tty0 fbcon=map:0 net.ifnames=0 sdhci_tegra.en_boot_part_access=1 quiet root=/dev/mmcblk0p1 rw rootwait rootfstype=ext4 console=ttyS0,115200n8 console=tty0 fbcon=map:0 net.ifnames=0 sdhci_tegra.en_boot_part_access=1

5

I don’t get clue in your second board design. You may need to probe the I2C signals on the board first.

6

The second board design is this one :
Jetson Nano Carrier rev A2_c.pdf (211.0 KB)

I will probe the I2C signals on the board, and I will let you know.

7

Thanks for your help.

Actually our carrier board had a problem with the i2c part.
Now it is corrected.

You may close the topic.

9

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