The telephone reports it's status to ANZV 0xe7
via command 0x2c
.
C8 04 E7 2C 00 07
C8 04 E7 2C 12 15
C8 04 E7 2C 10 17
Fixed length bitfield of one byte.
# Bitmasks
HANDSFREE = 0b0000_0001
UNKNOWN = 0b0000_0010
ESTABLISHING_CALL = 0b0000_0100
POWER = 0b0001_0000
ON_CALL = 0b0010_0000
Denotes whether the call is taking place via handset, or via handsfree (speaker phone). This flag has several effects discussed below.
HANDSET = 0b0000_0000
HANDSFREE = 0b0000_0001
When handsfree is active the BMBT displays the speaker phone icon.
I've noticed that switching between handset/handsfree also causes the following to be sent:
# Handsfree On
C8 07 E7 23 02 00 "C6" 05
# Handsfree Off
C8 06 E7 23 02 00 "20" 28
This is likely for MID, as 0xc6
is the character code for the speaker icon.
When handsfree is active, the BMBT and MFL will send volume control commands to telephone instead of radio.
# Handsfree: volume control sent to telephone
F0 04 C8 32 21 2F # BMBT
50 04 C8 32 11 BF # MFL
# Handset: volume conrol sent to radio
F0 04 68 32 21 8F # BMBT
50 04 68 32 11 1F # MFL
This is due to the telephone having an audio output that- unlike most audio sources, is not routed via the radio, thus requiring independent volume control.
I've not been able to discern what this represents. It might be related to an action on the handset.
NFI_OFF = 0b0000_0000
NFI_ON = 0b0000_0001
This denotes an incoming, or outgoing call.
# INACTIVE = 0b0000_0000
# ESTABLISHING = 0b0000_0100
When set, the following screen is displayed:
The layout will have no text, but this can be added via:
C8 <LEN> E7 23 80 20 "Incoming Call" <CS>
C8 <LEN> E7 23 81 20 "Incoming Call" <CS>
C8 <LEN> E7 23 82 20 "Incoming Call" <CS>
# TELEPHONE_OFF = 0b0000_0000
# TELEPHONE_ON = 0b0001_0000
Note: If bit is not set, GT will default to Main Menu. For example, if active bit is set for a call, upon setting to 0, GT will close Telephone and return to Main Menu.
Denotes if the a call is active.
# NO_CALL = 0b0000_0000
# ON_CALL = 0b0010_0000
When on a call the telephone icon on the BMBT will change to red, denoting "end call".
Like Handsfree, there's an additional message sent to ANZV, which may be for the MID.
# Start Call
C8 07 E7 23 01 00 "C7 C8" 05
# End Call
C8 07 E7 23 01 00 "20 20" 0A