NSLU2-Linux
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I have worked out how to put a 34-pin IDC male header on the inside of the small flat side of the slug (where the FCC compliance label is, in fact - specifically where the words "This device ... may cause undesired operations" are) and connect all the additional interfaces up to it.

There is space on the PCB for a upside-down (the pins which normally go through the PCB will be sticking up) right-angle PCB-mount male header to be glued on the empty slice of PCB between the resistors and the edge of the PCB, from C45 to the power plug, clearing L2 (the coil) by removing some of the pins from the 34-pin male header. Some other pins are removed from the 34-pin male header to indicate keying of different interfaces (these pins would be otherwise unusable when my preferred connectors are plugged in). The 34-pin header is glued to the board, not the case, so you are still be able to remove the board from the case (the header comes out with the board).

Note that you have to notch out the top of the internal PCB mount to allow the header to take that space. The bottom slug is the modified one.

A 34-pin female cable mount is plugged into the pins that are sticking up, and from there, the ribbon cable connected to the 34-pin female cable mount splays out to the respective connection points.

The various interfaces have been arranged so that the ribbon cable splits into three main areas (connections to the south of the front of the PCB, connections to the north-west of the rear of the PCB, and connections to the south-east of the rear of the PCB).

A couple of the signals had to be soldered underneath the cable on the front, cause I initially made a mistake and had the pinout of the connector reversed. Luckily I had only soldered 10 wires by that stage, but by the time I realised the mistake I had already cut these two wires too short to take them over to D5 and D6 where I originally intended to pick up pins 9 and 11.

The curly wire is the spare signal connected to pin 21.

And here is the hole I cut in the case. I only made the hole big enough to get to pins 15 through 34 - I figured that if I broke my slug bad enough to require JTAG, then I can just take the PCB out of the case to fix it.

Here is the pinout of the 34-way connector:

PinFunctionConnected to:CommentPinFunctionConnected to:Comment
33+3.3VJ2, pin 1Serial 034+3.3VX1205, pin 8I2C
31RXDJ2, pin 2Serial 032GNDX1205, pin 4I2C
29TXDJ2, pin 3Serial 030SCLX1205, pin 6I2C
27GNDJ2, pin 4Serial 028SDAX1205, pin 5I2C
25 Removed 26 Removed 
23+5VJS1 (STH)Misc24GNDJS1 (NTH)Serial 1
21SpareTBDSpare22RESETBTNS1 (RHS)Misc
19USB_DNEGR131 (LHS)USB Dev20RXDR128 (RHS)Serial 1
17USB_DPOSR130 (LHS)USB Dev18POWERBTNS2 (LHS)Misc
15GNDD5 (Centre)USB Dev16CTS_NR142 (LHS)Serial 1
13 Removed 14 Removed 
11+3.3VC156 (+ve)JTAG12 Removed 
9GNDC156 (-ve)JTAG10 Removed 
7TCKR134JTAG8 Removed 
5TDOR137JTAG6 Removed 
3TDIR133JTAG4 Removed 
1TMSR132JTAG2 Removed 

Note that pins 2, 4, 6, 8, 10, 12, 13 and 14 are not useable when a Digilent JTAG3 cable is used for the JTAG port.

Note that pins 25 and 26 are not usable when a dual-in-line IDC female plug is used for the serial and I2C ports.
Note that the +5V pin is near the USB Device area, but should not normally be connected for self-powered USB Device like the NSLU2.
Note that pin 21 is left unconnected to allow a four pin header for the USB to be plugged in without connecting to the +5V pin.

Here are the pinouts of the individual interfaces:

PinFunctionConnected to:Comment
34+3.3VX1205, pin 8I2C
33+3.3VJ2, pin 1Serial 0
32GNDX1205, pin 4I2C
31RXDJ2, pin 2Serial 0
30SCLX1205, pin 6I2C
29TXDJ2, pin 3Serial 0
28SDAX1205, pin 5I2C
27GNDJ2, pin 4Serial 0
26 NC 
--------
25 NC 
24GNDJS1 (NTH)Serial 1
23+5VJS1 (STH)Misc
22RESETBTNS1 (RHS)Misc
21SpareTBDSpare
--------
20RXDR128 (RHS)Serial 1
19USB_DNEGR131 (LHS)USB Dev
18POWERBTNS2 (LHS)Misc
17USB_DPOSR130 (LHS)USB Dev
16CTS_NR142 (LHS)Serial 1
15GNDS2 (RHS)USB Dev
--------
14 NC 
13 NC 
12 NC 
11+3.3VVCC near JTAGJTAG
10 NC 
9GNDGND near JTAGJTAG
8 NC 
7TCKR134JTAG
6 NC 
5TDOR137JTAG
4 NC 
3TDIR133JTAG
2 NC 
1TMSR132JTAG
PinSerial 0 (NSLU2 J2 pinout)
1+3.3V
2RXD
3TXD
4GND
PinI2C (standard Philips pinout)
1+3.3V
2GND
3SCL
4SDA
PinJTAG (Digilent JTAG3 Cable pinout)
1+3.3V
2GND
3TCK
4TDO
5TDI
6TMS
PinUSB Device Type-B Socket
1+5V
2USB_DNEG
3USB_DPOS
4GND
view · edit · print · history · Last edited by tman.
Based on work by tman, ByronT, and rwhitby.
Originally by rwhitby.
Page last modified on August 11, 2005, at 01:43 PM