ETRX357USB AND ETRX357USB-LRS
©2011 Telegesis (UK) Ltd
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ETRX357USB Product Manual (Rev 1.00)
5 ETRX357 I/O Connectivity
The I/Os of the built-in ETRX357 are connected as follows:
•
PA6 is connected to the LED (drive PA6 low to sink LED current).
•
PB3 is the CTS input for the ETRX357. Make sure PB3 is never defined as an output.
•
PB4 is the RTS input for the ETRX357.
Important Note: The lines for hardware handshaking are connected, so even when not using
hardware handshaking PB3 should never be defined as an output as this would drive against the
incoming CTS signal via a 1k
Ω
resistor and increase the current consumption.
6 Firmware upgrades
The firmware which is loaded onto the embedded ETRX357 Module can be upgraded over the air
or via the virtual COM port as described in the ETRX357 Development Kit manual.
Alternatively, access to the SIF programming interface is possible by opening the cover on the side
of the ETRX357USB ZigBee USB stick.
