FreeCalypso > hg > fc-small-hw
view lunalcd2/README @ 82:803667312307
sim-fpc-pasv: schem+BOM design complete
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Tue, 25 Oct 2022 06:13:01 +0000 |
parents | a2ce85275f63 |
children |
line wrap: on
line source
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.