User's Manual

Table Of Contents
MC46 Hardware Interface Description
DRAFT
MC46_HD_V02.8xb Page 60 of 98 21.08.2003
3.12.2.2 Using the SYNC pin to control a status LED
As an alternative to generating the synchronization signal, the SYNC pin can be used to
control a status LED on your application platform.
To avail of this feature you need to set the SYNC pin to mode 1 by using the AT^SSYNC
command. For details see [1].
When controlled from the SYNC pin the LED can display the functions listed in Table 19.
Especially in the development and test phase of an application, system integrators are
advised to use the LED mode of the SYNC pin in order to evaluate their product design and
identify the source of errors.
Table 19: Coding of the status LED
LED mode Operating status
Off MC46 is off or run in SLEEP, Alarm or Charge-only mode
600 ms On / 600ms Off No SIM card inserted or no PIN entered, or network search in
progress, or ongoing user authentication, or network login in
progress.
75 ms On / 3 s Off Logged to network (monitoring control channels and user
interactions). No call in progress.
75 ms on / 75 ms Off / 75 ms On /
3 s Off
One or more GPRS contexts activated.
Flashing Indicates GPRS data transfer: When a GPRS transfer is in
progress, the LED goes on within 1 second after data packets
were exchanged. Flash duration is approximately 0.5 s.
On Depending on type of call:
Voice call: Connected to remote party.
Data call: Connected to remote party or exchange of
parameters while setting up or disconnecting a call.
LED Off = SYNC pin low. LED On = SYNC pin high (if LED is connected as illustrated in Figure 23)
To operate the LED a buffer, e.g. a transistor or gate,
must be included in your application. A sample
configuration can be gathered from Figure 23. Power
consumption in the LED mode is the same as for the
synchronization signal mode. For details see Table 27,
SYNC pin.
Figure 23: LED Circuit (Example)