Laird DVK-WLM400, Manual, Page: 12 / 43

WISM+ DVK MANUAL
Version 1.00 Page 7
©
Laird Technology 2010
2.4 POWER/GND
2.4.1 DC Power Jack
The DC power jack accepts a 2mm plug from the AC/DC wall-brick power supply adapter. It is recommended that you
use the wall-brick power supply which is shipped with the Developer Kit, although, the input voltage range is 5
to 25
Volts (plus on the center).
2.4.2 Power Switch
The power switch when in the ON position will connect the DC power jack to the input of the switching power supply,
providing power to the entire development kit and the WISM+.
2.4.3 Switching Power Supply
The input to this switching power supply is provided from the DC power jack and is protected for reverse polarity with a
series diode. The output of the switching power supply provides power (3.3V) to the entire development board circuitry
as well as the WISM+.
2.4.4 WISM+ Input Power Jumper
This is a 4 position, dual row header. The two lower pins are connected to the WISM+ VCC input pins, and the two
upper pins are connected to the output of the 3.3V Dev Kit switching power supply. For normal operation, only one
jumper need be installed (shorting an upper pin to a lower pin).
To make WISM+ current measurements, remove the jumper and connect an ammeter between an upper and a lower
pin.
To insert an external DC power input, connect a power supply ground to one of the ground pads, and the positive side
of the power supply to one of the lower input power pins.
2.4.5 Ground Pads
These three thru-hole vias are made available simply to allow the user to have access to a system ground.
2.5 LEDs/INDICATORS
2.5.1 Power LED
This LED indicates DC power is being supplied to the WISM+ (DC power connection is made to the Dev Kit board and
the ON/OFF switch is in the ON position.
2.5.2 RUN LED
This LED is the WISM+ heartbeat. It will blink fast at boot time, pause, and then blink at a 1Hz rate once the WISM+
processor system has booted. This LED is driven by the WISM+ “HEARTBEAT” pin (WISM+ pin# 57).
2.5.3 WLAN LED
This LED will be lit when the WISM+ is wirelessly connected to another device (or joined a network). This LED is
driven by the WISM+ “
CONNECTED
2.5.4 SPI
” pin (WISM+ pin#59)
This LED will be lit whenever the SPI port is being used as the host interface, and communications are active over the
SPI port.