Hardware Design notes
XBee®-PRO 900HP/XSC RF Modules
26
n Microwave ovens
n Batteries
n Tall electrolytic capacitors
Use the following additional guidelines for optimal antenna performance:
n Do not place XBee modules with the chip antenna inside a metal enclosure.
n Do not place any ground planes or metal objects above or below the antenna.
n For the best results, mount the device at the edge of the host PCB. Ensure that the ground,
power, and signal planes are vacant immediately below the antenna section.
Recommended pin connections
The only required pin connections for two-way communication are VCC, GND, DOUT and DIN. To
support serial firmware updates, you must connect VCC, GND, DOUT, DIN, RTS, and DTR.
Do not connect any pins that are not in use. Use the PR and PD commands to pull all inputs on the
radio high with internal pull-up resistors. Unused outputs do not require any specific treatment.
For applications that need to ensure the lowest sleep current, never leave unconnected inputs
floating. Use internal or external pull-up or pull-down resistors, or set the unused I/O lines to outputs.
You can connect other pins to external circuitry for convenience of operation including the Associate
LED pin (pin 15) and the Commissioning pin (pin 20). The Associate LED pin flashes differently
depending on the state of the module, and a pushbutton attached to pin 20 can enable various
deployment and troubleshooting functions without you sending UART commands. For more
information, see Commissioning pushbutton and associate LED.
Only the programmable versions of these devices use the VREF pin (pin 14). For compatibility with
other XBee modules, we recommend connecting this pin to a voltage reference if you want to enable
analog sampling. Otherwise, connect to GND.
To Next Page
Loading...
Need help?
General
