User manual

User Manual
Version 1.1
2013-09-09
RaspBee ZigBee addon board
www.dresden-elektronik.de
Page 17 of 21
10. Hardware modifications
Besides the factory-default RaspBee configuration it is also possible to modify the hardware
to enhance its functionality.
10.1. Assemble the service header
The service interface provides the microcontroller programming interface of the radio
module. It is useful to assemble a 50 mil 10-pin header on the top side to ensure a proper
connection. We recommend the use of the listed header:
 MOUSER ELECTRONICS order number: 855-M50-3500542
 FARNELL order number: 1022305
 DIGI-KEY order number: 952-1383-ND
Figure 5: RPi service header (default not assembled)
The pin description can be found in Section 9 in Table 11. A detailed description of suitable
programmers and related software tools are listed in [5].
Note: Improper handling in respect of erasing or overwriting the MCU internal flash or
EEPROM completely or in parts may result in an unusable RaspBee unit. Modification
of the pre-allocated EEPROM memory sections or removal of the pre-installed
bootloader will irreversibly preclude restoring, booting or upgrading the shipping
firmware at all. dresden elektronik will neither support such modifications (see
Section 5.4 for details).
10.2. Using an external antenna
External antennas will be often used if an improved radio characteristics performance is
needed or the device is put into a metallized enclosure. In this case it is possible to assemble
a surface-mount coaxial connector. The footprint is designed to use the coaxial connector
‘U.FL-R-SMT-1(10)’ by HIROSE. It can be obtained from i.e. the following distributors:
 MOUSER ELECTRONICS order number: 798-U.FL-R-SMT-110
 FARNELL order number: 1688077
 DIGI-KEY order number: H11891CT-ND
Additionally the terminating resistor must be removed from the antenna port. Assemble a
22 pF coupling capacitor and a 10 k resistor in parallel directly next to the U.FL connector.
The RaspBee has been tested and measured with the approved antenna(s) listed in
Section 11.3.