Question about NXT JTAG J17 pin numbering

[tcwan]

Hi, I'm trying to connect a J-Link to my NXT, and am following the instructions in http://www.iar.com/website1/1.0.1.0/1483/QSSOLDER.pdf.

However, I have to make my own JTAG cable and am confused by the pin numbering for J17 on the NXT PCB.

The pins are arranged as follows on the board:

Code: Select all

o @
  o
  o
  o
  o
  o
  o
o o

where @ is a square via. Are the pins arranged from top to bottom (on the right column) as Pins 1-8? Do the two pins on the left column have any function or are they just mechanical supports?

T.C.

[schodet]

Looking at http://www.jstuber.net/lego/nxt-program ... dware.html, I can see that there is no tracks going to the pins on the left column.

Furthermore, looking at schematics, you can see there is the RA4 resistor network connected to pins 1 to 4, R90 to pin 5, GND to pin 6 and R89 between pin 7 and VCC3V (pin 8).

So I think the right pinout is:

Code: Select all

9  [1]
    2
    3
    4
    5
    6
    7
10  8

with [1] the square one.

[tcwan]

Hi Nico,

Great. Thanks!

T. C.