# HG changeset patch # User Mychaela Falconia # Date 1623787025 0 # Node ID 153b517ccc7a13ea7ae294859501f78bf4a92349 # Parent 6b02de9262774717f76867b000c863b3d6b42a24 FC-handset-spec section 1.7.2: make contrast with MIDI ringtone chips diff -r 6b02de926277 -r 153b517ccc7a FC-handset-spec --- a/FC-handset-spec Tue Jun 15 19:28:52 2021 +0000 +++ b/FC-handset-spec Tue Jun 15 19:57:05 2021 +0000 @@ -516,10 +516,12 @@ 1.7.2. Loudspeaker implementation The external amplifier chip for driving the 8 ohm loudspeaker will be TI -TPA6203A1, copied from Leonardo schematics and proven good on FCDEV3B. On -FCDEV3B this amplifier is fed with signal from Iota EAR output, but on the final -handset and on the Venus development board this amplifier will be fed with -signal from Iota AUX output instead. +TPA6203A1, copied from Leonardo schematics and proven good on FCDEV3B. It is a +"dumb" loudspeaker amplifier, as opposed to a much more complex chip that +combines the loudspeaker amplifier function with a MIDI ringtone player - see +section 1.8. On FCDEV3B this amplifier is fed with signal from Iota EAR output, +but on the final handset and on the Venus development board this amplifier will +be fed with signal from Iota AUX output instead. The loudspeaker amplifier has an on/off control by way of a Calypso GPIO; in order to save battery, this amplifier needs to be off normally, and only turn on