Building a REX

Building a REX from scratch, using the files and info released by Stephen Adolph.
Brian K. White - bw.aljex@gmail.com
Files Used
Pictures

BOM

Bill of Materials. Order each of these.
These are parts to build 3 REX boards, because you can't order fewer than 3 boards from OSHPark. If you only want to build one board, you'll have to order 3 pcbs from OSHPark, reduce the quantities of the parts on the DigiKey cart, and just discard 2 of the pcbs from OSHPark.

PCB

When you press "order it" you get 3 boards.

Parts, excluding the flash

This cart is pre-loaded with quantities to build 3 REX boards.

Flash

Order 1 flash chip per REX. (so, 3 chips if you want to build 3 boards)

Pick any version of the chip which matches this pattern:

AM29F800BB-##E*

Where:

## = Speed: 90 or lower (90 or faster)

E = Package: Only E, TSOP

* = Temperature range: Any

Example (what I got):

AM29F800BB-70EK

Assembly

Shape the PCB

Place a sheet of medium grit sand paper on a cutting board and sand the long edges of the pcb down until the holes are about half gone. Use the white marker lines in the corners. Sand until the edge of the board is almost to the lines, but the lines are still there.

Electronic Components

Install these parts:

AM29F800BB (pin 1 marker dot is hard to see because it's copper not silkscreen, but it's there)

XCR3064XL

LP2980

R1 = 0 ohm

R3 = 10K ohm

C4 = 1.0 uF

All other locations left empty.

Simple Drag Technique to solder the chips with an ordinary solder pen and flux. No fancy professional soldering station needed.

Spacer & Extractor

1/2" double sided tape

Cereal box

3/8" Ribbon

Apply double sided tape to bottom.

Cut a length of about 2 1/2" of ribbon, and melt the cut edges with the soldering pen to keep them from fraying. Stick the rex to the center of the ribbon, alighned lengthwise.

Add another piece of double sided tape on top of the ribbon.

Cut a piece of cereal box about 1/2" x 1-1/2", and stick that to the tape.

Flash the Firmware

There are two things to flash;

• The .jed, which configures the blank CPLD into a functional circuit or device. You must flash the .jed first.
• The firmware, which (I think?) runs on the device created by the .jed ?, and (this part is certain) includes an option-rom image loaded in one of the 32k blocks of flash, which contains REXMGR.

.jed

• Install LabTools 14.7 from Xilinx
  

https://drive.google.com/folderview?id=0Bys6eLbSbYyhVFBQSW1pclpjaWM

• Supply +5vdc to pin 1 of the board edge, and gnd to pin 14.

Same as the M100 would do when installed.

Simplest is use an empty Molex socket on a breadboard, and snap the module into the socket the same way it would be in a M100. Or I suppose you could just use an actual Model 100/102/200, if you didn't care about the data on it.

(link to searchable part numbers, there are at least two companies that made the sockets and carriers.)

(Contact Brian White bw.aljex@gmail.com for a socket. I got a load of 130 of them cheap.)

• Hook up a platform usb-ii to the jtag pins with a short section of single row pin header.

(The staggered/offset holes makes tension on the straight row of pins, which holds them in place and makes a solid contact without any fancy spring loaded sockets. Google "C-MOD S6 Manual" and see the drawing.)

• Temporarily pull PORT_EN high on the cpld by temporarily jumping from the vcc pin from the jtag, to R3, on the side closest to the center of the board. (Be careful and get this right. The other side of R3 is GND. If you short vcc to gnd you may burn out the 3.3vdc regulator (part number).) Just clip a test clip to the jtag vcc pin and manually hold the other end touching the side of R3 for the few seconds it takes iMPACT to program.

• While holding the PORT_EN jumper in place, use iMPACT to program the .jed file.

firmware

Follow the directions for the 4.9 update.
This happens to also serve as a way to do a first-time flash of the firmware and REXMGR software.

4.9 update directions

4.9 update files

References

User Manual

Sources and support files

PCB