changeset 75:c458b7159fbd

FC-handset-spec: add charging indicator LED
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 17 Sep 2021 18:31:08 +0000
parents e4eebf9ffce3
children 04080501911d
files FC-handset-spec
diffstat 1 files changed, 9 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/FC-handset-spec	Thu Sep 16 06:26:35 2021 +0000
+++ b/FC-handset-spec	Fri Sep 17 18:31:08 2021 +0000
@@ -792,6 +792,15 @@
 on/off switch is what will cause the chipset to boot in the 'charger plug' mode,
 or to activate charging functions in the firmware if the phone is already on.
 
+1.11.1. Charging indicator LED
+
+We are going to implement a TI-classic charging indicator LED controlled by
+Iota LEDC; the circuit is nothing more than a LED in series with a resistor,
+connected between the VCHG rail and Iota LEDC terminal.  The LED will probably
+be red (TBD), such indicator LEDs have low Vf, and because the positive source
+is USB +5V rather than VBAT, there should be no issues with LED brightness
+variation.
+
 1.12. Computer interface
 
 Our Calypso chip has no native USB, instead the host computer interface of all