Accessory - Nokia RH-44 Series Troubleshooting - Bb

CCS Technical Documentation

Accessory

Differential-ended external audio accessory connection is supported. Headset and data
cables can be directly connected to system connector or 2.5mm jack supporting TTY/TDD
or universal headset. Detection of the different accessories is based on the ACI code
residing inside the accessories, except for basic headset (HDB-4) and universal headset.
The UHJ is detected by the interrupt generated on GenIO(12). The basic headset is
detected via ACI detection algorithm. However, the ACI pin is always grounded.
It is the end user's responsibility to set the phone for TTY/TDD since there are too many
different TTY/TDD devices to be detected.
Active cover is detected by the A/D level on SLOWAD(4). There is 100k pull-up inside the
and 330k pull down on the active cover side. Once the cover is detected, Vflash2 will be
turned on to provide the power to the cover. The driving signal for the active cover is
provided from the output of the MIDI audio amplifier. It is AC-coupled to the cover input.
Issue 1 04/2003
Figure 17: LCD Interface
Nokia Corporation
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