wiki:802.11/Usage/UART

Version 2 (modified by murphpo, 9 years ago) (diff)

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Using the 802.11 Reference Design: UART

The 802.11 Reference Design hardware implements two MicroBlaze cores, CPU High and CPU Low. Both CPUs have UART cores attached to their peripheral buses. The UARTs act as STDIN and STDOUT for programs running in the CPUs. Every MAC application in the reference design prints boot and debug info the UART. Each application also implements some control via UART input. The pre-application specifics are described below.

UART Mux

The WARP v3 board has one UART-USB transceiver. Refer to the USB-UART Howto for instructions on setting up your PC to use the USB-UART interface.

The 802.11 Reference Design implements a 2:1 mux which allows either CPU's UART to use the UART-USB connection. The mux is controlled by the right-most switch on the user IO DIP switch. Set the switch high (up) to select the CPU High UART, low to select the CPU Low UART. The UART mux responds immediately. You can safely change the UART selection at runtime.

AP UART

The normal UART output on boot of the AP application is:

----- Mango 802.11 Reference Design -----
----- v1.0 ------------------------------
----- wlan_mac_ap -----------------------

------------------------
DRAM SODIMM Detected
Tx Queue of 3413 placed in DRAM: using 13652 kB
Initializing Event log (1044664320 bytes) at 0xC1BBB000
BSS Info list (len 768) placed in DRAM: using 60 kB
1 Eth Tx BDs placed in BRAM: using 64 B
239 Eth Rx BDs placed in BRAM: using 14 kB
------------------------
WARPNet v2.1.0 WLAN EXP v1.0.0 (compiled Oct 22 2014 13:49:16)
  ETH B MAC Address: 40:D8:55:04:21:4B
  ETH B IP  Address: 10.0.0.0  (1000 Mbps)
  Configuring ETH B for AXI FIFO mode with 1514 byte buffers (1 receive, 1 send)
  Listening on UDP ports 9500 (unicast) and 9750 (broadcast)
  Not waiting for Ethernet link.  Current status is: not ready.
    Make sure link is ready before using WARPNet.
End WARPNet WLAN Exp initialization
WLAN MAC AP boot complete:
  SSID    : WARP-AP
  Channel : 1
  MAC Addr: 40-D8-55-04-21-4A


Press the Esc key in your terminal to access the UART menu

Hitting the ESC key will show the AP's interactive menu:

********************** AP Menu **********************
[1] - Interactive AP Status
[2] - Print Queue Status
[3] - Print all Observed Statistics

[c/C] - change channel (note: changing channel will
        purge any associations, forcing stations to
        join the network again)
[r/R] - change default unicast rate
[s]   - change SSID (note: changing SSID will purge)
        any associations)
*****************************************************

Option 1 will show a sub-menu with commands to reset all Tx/Rx statistics and to de-authenticate all stations.

Option 2 will show the current c

During normal operationthe AP will print UART messages as stations join and leave the AP's network. For example, when the first client joins the AP:

Authenticated, Unassociated Stations:

(MAC time = 404586220 usec)
|-ID-|----- MAC ADDR ----|
| 01 | F0:D1:A9:6C:86:A6 |
|------------------------|

Authenticated, Associated Stations:

(MAC time = 404609451 usec)
|-ID-|----- MAC ADDR ----|
| 01 | F0:D1:A9:6C:86:A6 |
|------------------------|

The first message shows the client part way through the association handshake (post authentication, pre association). The second message shows the client successfully authenticated. As more clients join and leave the BSS these node lists will grow and shrink.