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comparison FC-handset-spec @ 75:c458b7159fbd

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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
comparison
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74:e4eebf9ffce3 75:c458b7159fbd
790 chip datasheet (TWL3025_SWRS021.pdf), same as in Pirelli DP-L10 and Motorola 790 chip datasheet (TWL3025_SWRS021.pdf), same as in Pirelli DP-L10 and Motorola
791 C1xx phones. Presentation of USB +5V to Iota VCHG terminal past the charging 791 C1xx phones. Presentation of USB +5V to Iota VCHG terminal past the charging
792 on/off switch is what will cause the chipset to boot in the 'charger plug' mode, 792 on/off switch is what will cause the chipset to boot in the 'charger plug' mode,
793 or to activate charging functions in the firmware if the phone is already on. 793 or to activate charging functions in the firmware if the phone is already on.
794 794
795 1.11.1. Charging indicator LED
796
797 We are going to implement a TI-classic charging indicator LED controlled by
798 Iota LEDC; the circuit is nothing more than a LED in series with a resistor,
799 connected between the VCHG rail and Iota LEDC terminal. The LED will probably
800 be red (TBD), such indicator LEDs have low Vf, and because the positive source
801 is USB +5V rather than VBAT, there should be no issues with LED brightness
802 variation.
803
795 1.12. Computer interface 804 1.12. Computer interface
796 805
797 Our Calypso chip has no native USB, instead the host computer interface of all 806 Our Calypso chip has no native USB, instead the host computer interface of all
798 Calypso-based systems consists of two UARTs. On our development boards starting 807 Calypso-based systems consists of two UARTs. On our development boards starting
799 with FCDEV3B, we got used to interfacing to both of these UARTs by way of 808 with FCDEV3B, we got used to interfacing to both of these UARTs by way of