view lunalcd2/README @ 62:907bff95244d

lunalcd2/src/Makefile: generate elements.pcb
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 25 Jun 2021 19:11:21 +0000
parents a2ce85275f63
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Formike KWH020ST23-F01 is a candidate LCD module being considered for our
FreeCalypso Libre Dumbphone dream handset.  Prior to building the actual
handset, we will need to build our FC Venus development board, and prior to
starting the design of this Venus board, we are going to test the proposed LCD
module in our currently existing Luna environment.  The modular LCD subsystem
board being designed in this directory is intended to be a drop-in replacement
for our previous Luna LCD board from 2020-04 (lunalcd1 directory), to be
connected to the same Caramel/C2 motherboards, with the resulting system
configuration still being Luna (not Venus).

In addition to changing out the LCD module, the backlight driver circuit is
being changed to the MAX1916-based one described in FreeCalypso Handset
Specification section 1.4.4, with a set of DIP switches selecting different LED
currents - the intent is to find appropriate LED currents for the different
display brightness modes that will be needed in the actual handset.  A current
measurement resistor is also being inserted in the LCD (not backlight) power
supply path - we will be exercising the LCD controller/driver chip's power-
saving sleep modes, and we need to be sure that they actually reduce the 2.8V
supply current draw as expected.