Specifications
XBee®/XBee‐PRO®SERFModules
©2009DigiInternational,Inc. 115
Warning: If programming firmware through the SIF interface, be aware that uploading firmware
through the SIF header can potentially erase the XBee bootloader. If this happens, serial firmware
updates will not work.
(The pinout for the SIF headers are shown in chapter 1.)
Writing Custom Firmware
The XBee/XBee-PRO module can be used as a hardware development platform for the EM250.
Custom firmware images can be developed around the EmberZNet 2.5.x and 3.x mesh stacks (for
the EM250) and uploaded to the XBee.
Warning: If programming firmware through the SIF interface, be aware that uploading firmware
through the SIF header can potentially erase the XBee bootloader. If this happens, serial firmware
updates will not work.
Regulatory Compliance
XBee modules are FCC and ETSI certified for operation on all 16 channels. The EM250 output
power can be configured up to 3dBm with boost mode enabled.
XBee-PRO modules are certified for operation on 14 of the 16 band channels (channels 11 - 24).
The scan channels mask of XBee-PRO devices must be set in the application to disable the upper
two channels (e.g. 0x01FFF). The XBee-PRO contains power compensation circuitry to adjust the
output power near 18dBm or 10dBm depending on the part number. For best results, the EM250
should be configured with an output power level of 0dBm (or -2dBm if boost mode is enabled).
The end product is responsible to adhere to these requirements.
Enabling GPIO 1 and 2
Most of the remaining sections in this chapter describe how to configure GPIO 1 and 2 to function
correctly in custom applications that run on the XBee and XBee-PRO modules. In order for GPIO
pins 1 and 2 to be configurable, the application must set the GPIO_CFG register to enable GPIO 1
and 2. Bits 4 - 7 in the GPIO_CFG register control the functionality of various GPIO lines. The
following table lists values for these bits that enable GPIO 1 and 2. Other functionality is affected
by these settings. See the EM250 datasheet from Ember for a complete listing of functionality.
Example 1
The following code enables GPIO 0, 1, 2, 3, 9, 10, 11, and 12 and maintains all other GPIO_CFG
bits.
int16u x;
x = GPIO_CFG;
x &= (0xFF0F);// Clear bits 4 - 7
GPIO_CFG = x;
Example 2
The following code enables GPIO 0, 1, 2, 3, and 12 and maintains all other GPIO_CFG bits.
int16u x;
x = GPIO_CFG;
GPIO_CFG[7:4]Enabled Functionality Enabled Functionality
0000 GPIO 0, 1, 2, 3, 9, 10, 11, 12
0111 0111GPIO 0, 1, 2, 3, 12
1010 GPIO 0, 1, 2, 3
1101 GPIO 0, 1, 2, 3, 11, 12