jetson tx2 usb problem

Autonomous Machines Jetson & Embedded Systems Jetson TX2
1

HI,
The usb1 port (pin A38 and A39 of jetson main connector) does not recognize any USB devices (mouse…).
The environment is:

  • 5V to devices always present (no usb regulator chip is used)
  • EN1 signal left open (it should be pull-uped by Jetson itself)
    the devices (mouse …) are working fine in other environments like PC…
    the D+ and D- are correctly connected between jetson and usb connector
    the jetson usb are working fine into own jetson evaluation board

Please, is there someone able to give me suggestions

thank you in advance
maurizio stefani

2

Hi, EN to control vbus load switch is necessary, otherwise there might be sequence issue which can cause such problem you met.

3

HI, thank you for the answer,
could you please explain what is happening leaving the +5V active always and EN signal pull-uped to 3.3V?
I understand that Jetson actives the power and, at mean time, read the EN signal to recognize if a over-current occur. If no over-current EN is managed by Jetson itself only.
What could be different is the the Jetson module want to remove the power.

thank you in advance for any help
maurizio stefani

4

It could cause some system errors if pull EN to always-on rail. Please just follow guide to use default EN signal.

5

HI,
Following your suggestion,
I put the USB Power Distribution chip (I used the TPS2065, with EN active high), but the enable sent by Jetson is low and than no usb power voltage is generated

I am quite sure that the power voltage circuit is correct.

What I see is that on the jetson evaluation module the en (EN1) is high

any suggestion?
maurizio

6

Please, I am continuing to check the usb interface,
I see that the pins

  • A17 and A18 are set to 0, they are USB0_EN and USB1_EN (note that I am using USB1_EN)
  • A19 USB2_EN to 1
    I am checking the signals just with a 4.7Kohm pull-up on ENs to be sure that the level are defined.
    Looking with scope the 3 signals have no change from power-on

please the control signals are set as follow:
A1 A2 B1 B2 C1 C2 VDD_IN TO 12V
C7 BATLOW# not connected
A48 CARRIER_PWR_ON it is output
B7 CARRIER_STBY# it is output
A49 CHARGER_PRSNT# it is connected to gnd in order to start immediately
A7 CHARGING# left open
C16 FAN_PWM left open
B17 FAN_TACH left open
E1 FORCE_RECOV# left open
B50 POWER_BTN# left open
A47 RESET_IN# left open
A46 RESET_OUT# it is output
E2 SLEEP# left open
B8 VIN_PWR_BAD# left open
C9 WDT_TIME_OUT# left open
A50 VDD_RTC left open, with no capacitor
C8 BATT_OC left open
B48 SYS_WAKE# left open
B49 MOD_PWR_CFG_ID left open (the jetson module is TX2)

please, any suggestion?
maurizio stefani

7

Can the system power up normally? What’s the difference between your USB part design and reference? Can you share schematic of USB part?

8

Hi set another post, because I am not able to attach the files

please see the new one

maurizio

Schematic Prints_2.pdf (24.2 KB)

Schematic Prints pag_1.pdf (63.4 KB)

9

HI,
continuing to check the usb problem, I tryed to use a switch to power-on the jetson (like the evaluation board). It does not worked, looking to the POWER_BTN signal (where I put the switch between it and gnd) I did not see the pull-up voltage (5V). It seems that the jetson module does not generate the VDD_5V0_IO_SYS internal signal.
All voltage generated by my carrier board are enabled by CARRIER_PWR_ON (pin A48), than up to the jetson does not start on the VDD_IN is present.
Is it correct?

any suggestions
maurizio stefani

10

HI,
I am sorry to disturb the forum,
I would resume how I can work with Jetson module:

  • I need to start immediately from VDD_IN, for that I connected A49 (CHARGER_PRSNT#) to ground.
    all other control signals are left open (for details please referring to my previous email)
    Under this condition the module starts as VDD_IN is set, the system seems to work and I am able to use the Jetson LAN.

The problem occur on USB port, I did not see the USB1_EN_OC# to level “1”. In order to avoid other problem i put a large pull-up resistor (4.7K) between the USB1_EN_OC# and 3.3V. Nothing is changing the signal remains low

I hope that this additional info can help to tell me a solution

thank you
maurizio

11

HI, someone can help me for usb problem?

thank you
maurizio

12

HI,
following the problem relevant to usb1_en,
is there a way to read the jetson gpio status?

thank you
maurizio stefani

13

HI,
I am waiting for any suggestion about the problem on USB port (port 1 and 2) that I am finding.
is there someone can help me?

Thank you in advance
maurizio stefani

14

Not sure about the root cause, what’s the difference between your USB part design and reference? No clue found in your schematic…

15

HI,
thank you for the answer,
I checker the USB connection, and I find them correct.

any other suggestion or any pin to check?

thank you

16

Did you try manually pull up EN of vbus load switch to output 5V or just connect vbus to a fixed 5V rail?

17

HI, thank you to all for the help, but the problem remains.
Let me resume the conditions:

  • the jetson module is on, I work with LAN with no problem.
    The USB 1 and USB0 do not work, looking arund them I see:
  • USB0_EN_OC# (pin A17) and USB1_EN_OC# (pin A18) are at “0”. I removed the USB switching chip and I connected a 4.7K pull-up to 3.3V (this to simulate the logic chip IO removed). But the 2 signals remain low.

Furthermore
From the doc you suggested:
I see that the voltage on these pins is generated by internal VDD_5V0_IO_SYS, may be this voltage is missing.

  • How can I check it?
  • In which condition the jetson module set the VDD_5V0_IO_SYS?

Again,
I set the USB0_VBUS_DET (pin B37) directely to 5V, is it correct?
All voltages (5V, 3.3V, 1.8V) are generated after CARR_PWR is set.
Please not that I left VDD_RTC left

waiting for you answer or any other suggestion.

thank you
maurizio

18

USB0_VBUS_DET should be connected to vbus pin of USB0 port. Can you fix all difference and keep totally same to reference design? Otherwise it is hard to find the root cause.

19

HI,
thank you for the answer, but please consider taht I can not destroy my carrier board, furthermore I am not sure to can produce a new PCB with no problems.

Please,
looking to the doc.

  1. it seems that the usb0_en and usb1_en are generated by the VDD_5V0_IO_SYS, is it correct?
  2. I understand that this voltage is generated by the Jetson module internally, is it correct?
  3. this signal is present on the evaluation board also, if it is necessary to use it to generate the usb_en signals, how this voltage “enters” into the Jetson module?

Could you please supply another site or people where I can address these questions

waiting for your suggestion
maurizio stefani

20

VDD_5V0_IO_SYS is generated on carrier board not from module. EN0 and EN1 have nothing to do with VDD_5V0_IO_SYS and are supplied in module. You can find these in DG or reference schematic.