Friday, October 20th 2017, 11:28pm UTC+2

You are not logged in.

  • Login
  • Register

Dear visitor, welcome to SEGGER Forum. If this is your first visit here, please read the Help. It explains how this page works. You must be registered before you can use all the page's features. Please use the registration form, to register here or read more information about the registration process. If you are already registered, please login here.

shamanhugh

Beginner

Date of registration: Jun 9th 2017

Posts: 5

1

Friday, June 9th 2017, 1:04pm

[SOLVED] Rasperry pi 3, VTarget = 0.000V. Pin and cable are tested by multimeter and show 3.26V.

Hi,

I am trying to debug my rasperry pi 3 using J-Link edu. I connect the pins as following (The links are generated and made public by dropbox).

https://www.dropbox.com/s/76mba0selrayuq…nk-pin.png?dl=0

And I am using J-Link Commander v4.92 on my Win 7 Ultimate. However, when I 'st' and 'hwinfo', I get the following output.

https://www.dropbox.com/s/oa9s7rwjbzi6r5…nk-out.png?dl=0

I have tested pin 1 on rasberry pi 3 using multimeter and it's showing 3.26V. Then I test the output of pin 1 on the other side of the jtag cable , it also gives me 3.26V.

Can anyone help me out?

Thank you!

This post has been edited 3 times, last edit by "shamanhugh" (Jun 9th 2017, 1:11pm)


SEGGER - Niklas

Super Moderator

Date of registration: Oct 6th 2014

Posts: 1,684

2

Friday, June 9th 2017, 3:28pm

Hi,


in the pinout it says that pin 1 is connected to N/A.
You need to connect pin 1 of J-Link to a pin of the raspberry which provides VTREF / VDD.


Best regards,
Niklas
Would you like to be added to the J-Link software update notification list, so you get informed automatically when a new version becomes available?
Just write me a PM or in case you want to subscribe to it yourself, please use this link: Link
Notification for J-Link, J-Link Debugger, SystemView & J-Scope: Link
Notification for Embedded Studio: Link

shamanhugh

Beginner

Date of registration: Jun 9th 2017

Posts: 5

3

Friday, June 9th 2017, 7:54pm

Hi,

Thank you for your reply. N/A there simply means it is not GPIO.

Please refer the pinout of rasperry pi 3 as following.

https://www.dropbox.com/s/zljag7f2j5lf6hy/pi3_gpio.png?dl=0


Thank you!

SEGGER - Niklas

Super Moderator

Date of registration: Oct 6th 2014

Posts: 1,684

4

Friday, June 9th 2017, 8:09pm

Hi,


in order to be able to communicate with the target, you need to connect a ref voltage of the pi to Pin 1 of the J-Link.

Quoted

Pin 1 (VTREF) is the target reference voltage.
It is used to check if the target has power, to create the logic-level reference for the input comparators and to control the output logic levels to the target. It is normally fed from Vdd of the target board and must not have a series resistor.


The 20 pin JTAG/SWD pinout of J-Link can be found here:
https://www.segger.com/products/debug-pr…ace-description


Best regards,
Niklas
Would you like to be added to the J-Link software update notification list, so you get informed automatically when a new version becomes available?
Just write me a PM or in case you want to subscribe to it yourself, please use this link: Link
Notification for J-Link, J-Link Debugger, SystemView & J-Scope: Link
Notification for Embedded Studio: Link

shamanhugh

Beginner

Date of registration: Jun 9th 2017

Posts: 5

5

Friday, June 9th 2017, 8:26pm

Hi,

I have connected the pin 1 on rasperry pi to pin 1 on j-link. I think I get this right. And I have used multimeter to double check.

My question is, why it still telling me target power low even if I have already connected the right pins.

Thank you!

SEGGER - Niklas

Super Moderator

Date of registration: Oct 6th 2014

Posts: 1,684

6

Monday, June 12th 2017, 9:23am

Hi,


Sorry, I misread what you had written before.

Well first of all V4.92 is pretty ancient.
While it should work though, could you please give the current version of the J-Link software & documentation pack a try?

What happens if you connect a 3.3V Battery or "Lab Voltage" to Pin 1 and Pin 4?
Please note that Pin 14/16/18/20 are reserved on current J-Link probes.

Best regards,
Niklas
Would you like to be added to the J-Link software update notification list, so you get informed automatically when a new version becomes available?
Just write me a PM or in case you want to subscribe to it yourself, please use this link: Link
Notification for J-Link, J-Link Debugger, SystemView & J-Scope: Link
Notification for Embedded Studio: Link

shamanhugh

Beginner

Date of registration: Jun 9th 2017

Posts: 5

7

Monday, June 12th 2017, 3:00pm

Hi,

I am using J-Link Commander V6.4b now. And I have connected two AA 1.5V batteries to get 3.18V voltage. I connect the + and - side of them to the pin 1 and pin 4 respectively. But still, the J-Link commmender is complaining VTref = 0.000V.

Thank you!

SEGGER - Niklas

Super Moderator

Date of registration: Oct 6th 2014

Posts: 1,684

8

Monday, June 12th 2017, 6:31pm

Hi,

Quoted

J-Link Commander V6.4b

There is no version named "V6.4b". Are you referring to "6.14b"? If yes, why did you not download the latest version (V6.16b) instead of a "random" version?

Quoted

And I have connected two AA 1.5V batteries to get 3.18V voltage. I connect the + and - side of them to the pin 1 and pin 4 respectively. But still, the J-Link commmender is complaining VTref = 0.000V.

If this is the case, and you did not confuse the pins somehow, the J-Link is broken.
For J-Link EDU, you need to contact the reseller regarding the RMA procedure.


Best regards,
Niklas
Would you like to be added to the J-Link software update notification list, so you get informed automatically when a new version becomes available?
Just write me a PM or in case you want to subscribe to it yourself, please use this link: Link
Notification for J-Link, J-Link Debugger, SystemView & J-Scope: Link
Notification for Embedded Studio: Link

shamanhugh

Beginner

Date of registration: Jun 9th 2017

Posts: 5

9

Monday, June 12th 2017, 9:11pm

Hi,

I don't know why I typed 6.4b... I was using 6.16b. Sorry about that.

Yea, I will contact the seller.

Thank you for your help!

Sincerely,
Ruide