Main PCB: Modified with external RP-SMA Connectors
Main PCB: Top
Main PCB: Bottom
The AR934x platform (AR7370) provides 23 GPIOs. Some of them are used by the router for status LEDs, buttons and other stuff. The table below shows the results of some investigation (active state low):
Voltage level at GPIO in output-mode
gpioX/value in input-mode when GPIO is:
Pulled to GND
Pulled to Vcc
To make the GPIOs available via sysfs, the required ones have to be exported to userspace, as it is explained on a page of the Squidge-Project. Kernel modules occupying that resource need to be removed before (e.g. “leds-gpio” and “gpio-buttons”). In output-mode, voltage levels of the GPIOs were measured against GND, after the value 1 or 0 had been written to /sys/class/gpio/gpioX/value. In input-mode, the value of the file /sys/class/gpio/gpioX/value was read when the GPIO was floating (initial state), pulled to GND or pulled to Vcc.
→ port.serial general information about the serial port, serial port cable, etc.
Serial console can be plugged to JP6: connector lacks, it has to be soldered on the board.
How to connect to the Serial Port of this specific device:
You can easily find it, look at the flash in the center of PCB, the serial connector sits next to it:
JP6 . . . .
4 3 2 1
The settings are: 115200 bauds, 8 bits, no parity, 1 stop bit (115200 8N1)
You are root, once connected to the serial port.
→ port.jtag general information about the JTAG port, JTAG cable, etc.
Jtag pins seems to be located in JP1, but the connector lacks.
How to connect to the JTAG Port of this specific device:
The machine runs “U-Boot 1.1.4 Rev: 20 (Nov 9 2011 - 19:56:29)”, with the following memory layout:
Top of RAM usable for U-Boot at: 88000000
Reserving 162k for U-Boot at: 87fd4000
Reserving 192k for malloc() at: 87fa4000
Reserving 44 Bytes for Board Info at: 87fa3fd4
Reserving 36 Bytes for Global Data at: 87fa3fb0
Reserving 128k for boot params() at: 87f83fb0
Stack Pointer at: 87f83f98