Version 1.17 2011-09
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Appendix A - Application Notes
Usually only a subset of the available functionality is of interest to the designer. In addition,
depending on the host system, the electrical interface can be designed in many ways. The
designer can use the step-by-step guide in this chapter as an aid in the design process.
A.1 Step-by-Step Guide
Table 20: Step-by-step guide with Yes and No answers.
Question
Yes
No
Are you going to integrate the OEM
Serial Port Adapter in a metal enclo-
sure?
The internal antenna models
cannot be used. Use the
OEMSPA311x or OEMSPA331x.
You are free to choose
between the products. The
internal antenna models
are lower cost and are
easier to design-in. How-
ever, an external antenna
could give better range.
Do you wish to use logic level when
communicating with the OEM Serial
Port Adapter?
See section A.2.2.1 for electrical
design.
See section A.2.2.2 -
A.2.2.3 for electrical de-
sign.
Do you want to use RS232 as the
physical serial interface?
See section A.2.2.2 for electrical
design.
Go on to next point.
Do you want to use RS485 or RS422
as the physical serial interface?
See section A.2.2.3 - A.2.2.4 for
electrical design.
Go on to next point.
Is low power consumption important?  The power consumption can be
reduced by enabling the stop
mode, see Table 10. The stop
mode is controlled with the DSR
pin, see section 2.5. The power
consumption is optimized with
3.2-3.3 V supply voltage.
Go on to next point.
Do you wish to connect LEDs to the
OEM Serial Port Adapter?
See section A.2.3 for design
examples for connecting the
LEDs.
Go on to next point.
Do you want to detect the status of
the module with a controller?
See Chapter 3, Table 14 for sta-
tus detection and section A.2.3
for electrical design.
Go on to next point.
Do you wish to utilize the restore
switch?
See section A.2.3.2 for electrical
design.
Go on to next point.
Do you wish to utilize the Function
switch (Connect on external sig-
nal)?
See section A.2.3.4 for electrical
design.
Go on to next point.
Do you want to manually reset the
module?
See section A.2.4 for electrical
design. Use a double row con-
nector. See section 5.2.1.2.