Thu., Nov. 17th

Had a little time between meetings, so decided to come into the lab to test the connections on the newly-soldered 40-pin header on Wi-Fi board #3.  Actually, I realized I can't test the connections to J9 because that is on the other side of the 0-ohm resistor jumpers R7-R14, which are not presently populated (their pads are underneath the level-shifter chip U3).  So instead, I'll test by running the GPS app on the DE3 board.

Pins of J2 that we need for the serial are:

• Pin 10 (yellow wire)   - (From DE3) Autorun (DE9 pin 4) -> M_DSR (To WiFi)        - Optional.
• Pin 11 (black wire)    - GND                          (DE9 pin 5)
• Pin 19 (green wire)    - (From DE3) RTS       (DE9 pin 7) -> M_CTS  (To WiFi)        - Handshaking in (optional)
• Pin 21 (red wire)       - (To DE3)     RX         (DE9 pin 2) <- M_TX    (From WiFi)
• Pin 23 (tan wire)        - (To DE3)     CTS      (DE9 pin 8) <- M_RTS  (From WiFi)    - Handshaking out (optional)
• Pin 25 (blue wire)      - (From DE3) TX        (DE9 pin 3) -> M_RX    (To WiFi)
• Pin 27 (purple wire)   - (To J10 pin 2 /EN)                      <- +3V out  (From WiFi)    - Disables level-shifted input.-

To start out, I'm just going to connect pins 11 (GNS), 21 (M_TX), 25 (M_RX), and 27 (/EN).

Starting the server to prepare for the run.  (First I moved the last round of log files to a subfolder with today's date.)

I have to open the GPS app project in Quartus.  Did that (version in C:\f).  Plugged in USB.  Powered up board.  It's running the builtin demo.  Starting programmer.  Selecting USB blaster.  Burning image.  Wait, forgot to start Wi-Fi first.  Powering DE3 off.

On Wi-Fi, connecting pins 1+2 of JP2 to enable USB power.  Now it's powering up.

Looking at the top-level file (DE3_GPSapp.v), it looks like I am going to have to add CTS/RTS after all, because the design is expecting them.  OK, added those two wires.

Now, powering up DE3 again, and re-programming design.  Nuthin!  (Just "--" on 7-seg display)

I have to go over to ECE now.  Things to try tomorrow:

• Hook up GPS module
• Check baud rate
• Run design in debugger (in legacy Nios II IDE)

*     *     *

Came back in later in the evening to work some more on the DE3 board connections.  I've now greatly simplified the design of the connections.  I've eliminated the ribbon cable and serial cable and all of the wire-wrap.  I did some reassignments of the DE3's GPIO header pins to group related pins closer together.  I also figured out that I can eliminate the level shifter (I think) by connecting directly to the GPS kit's internal logic-level Tx/Rx nodes instead of going through its level-shifter and DE9 connector.  And I figured out how to power the GPS kit directly from the DE3 board using +3.3V out.

New pin assignments:

• GPIO 0 (Wi-Fi) - Inner header
• Pin 11 = +5V power supply to Wi-Fi module.
• Pin 27 (GPIO0_D20) <-- Serial CTS input from Wi-Fi kit
• Pin 28 (GPIO0_D21) --> Serial RTS output to Wi-Fi kit
• Pin 30 = GND supply to Wi-Fi module.
• Pin 31 (GPIO0_D22) <-- Serial RxD input from Wi-Fi kit
• Pin 32 (GPIO0_D23) --> Serial TxD output to Wi-Fi kit
  
• GPIO 1 (GPS) - Outer header
• Pin 27 (GPIO1_D20) <-- PPS input from GPS kit, J4 pin 15.
• Pin 29 = +3.3V power output to GPS kit.
• Pin 30 = GND supply to GPS kit.
• Pin 31 (GPIO1_D22) <-- Serial RxD input from GPS kit, J5 pin 15 (UART0TX).
• Pin 32 (GPIO1_D23) --> Serial TxD output to GPS kit, J5 pin 16 (UART0RX).

The Adafruit jumper wires currently being used are not colored optimally, since I was running low on colors, but I ordered some more of them and they should arrive soon.  I can replace the temporary ones I have now with more sensibly-colored ones when they get in.

I think the new GPS communication setup is working because I got a "Yo" on the 7-segment display, indicating a line was received.  Still need to test communication in the other direction though.  (Sending config commands from the DE3 to the GPS.)

Tomorrow I'll hook up the new Wi-Fi board (it's drying at the moment; I had to solder a header pin for +5V power input) and do a complete test of this new CTU setup.