# The official voice call kit for FCDEV3B consists of a SparkFun COM-09151
# loudspeaker and a CUI CMC-9745-130T microphone.  The present audio mode
# config has been tuned as follows:
#
# 1) AEC is enabled as needed for all not-held-to-ear loudspeaker setups;
#
# 2) The microphone gain has been tuned to provide the most natural
# voice levels to parties on the far end of the call, matching standard
# phones;
#
# 3) The sidetone level has been turned down: the default -5 dB is too loud
# and causes singing effects with the raised microphone gain.

mic default {
	gain 8		# tuned for CMC-9745-130T and FCDEV3B mic input circuit
	output-bias 0	# 2.0V appears to be correct for CMC-9745-130T
# Mic has very flat frequency response, thus no FIR needed
}

# We don't have a FIR filter for our SparkFun COM-09151 loudspeaker.  There is
# no datasheet for this speaker on SparkFun website, thus we don't know its
# frequency response curve, and even if we got the needed data, the work to
# create a flattening filter would probably be more than we can justify.

speaker ear {
	gain 0		# left at default for now
}

# The canon seems to be to disable the sidetone altogether in loudspeaker
# setups, but we set it to the lowest level instead, so we keep exercising
# this chipset feature - our FCDEV3B is unusual in that the loudspeaker
# is the only way to exercise voice calls.

sidetone -23

# The AEC configuration has been copied from Pirelli DP-L10, or more
# specifically, Pirelli's loudspeaker mode AEC config.  Unfortunately
# we lack sufficient Calypso DSP documentation to even understand most
# of these tunable settings, let alone actually tune them, hence
# copying Pirelli's config is the best we can do at the moment.

aec-new 2 1 0x14 0xCCC 0xFFF 0x4000 0x32 0x1000 0x1000 0 4 0x60