FreeCalypso > hg > fc-small-hw
comparison lunalcd2/README @ 55:a2ce85275f63
lunalcd[12]/README written
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Wed, 23 Jun 2021 08:23:10 +0000 |
| parents | |
| children |
comparison
equal
deleted
inserted
replaced
| 54:91798685fd8d | 55:a2ce85275f63 |
|---|---|
| 1 Formike KWH020ST23-F01 is a candidate LCD module being considered for our | |
| 2 FreeCalypso Libre Dumbphone dream handset. Prior to building the actual | |
| 3 handset, we will need to build our FC Venus development board, and prior to | |
| 4 starting the design of this Venus board, we are going to test the proposed LCD | |
| 5 module in our currently existing Luna environment. The modular LCD subsystem | |
| 6 board being designed in this directory is intended to be a drop-in replacement | |
| 7 for our previous Luna LCD board from 2020-04 (lunalcd1 directory), to be | |
| 8 connected to the same Caramel/C2 motherboards, with the resulting system | |
| 9 configuration still being Luna (not Venus). | |
| 10 | |
| 11 In addition to changing out the LCD module, the backlight driver circuit is | |
| 12 being changed to the MAX1916-based one described in FreeCalypso Handset | |
| 13 Specification section 1.4.4, with a set of DIP switches selecting different LED | |
| 14 currents - the intent is to find appropriate LED currents for the different | |
| 15 display brightness modes that will be needed in the actual handset. A current | |
| 16 measurement resistor is also being inserted in the LCD (not backlight) power | |
| 17 supply path - we will be exercising the LCD controller/driver chip's power- | |
| 18 saving sleep modes, and we need to be sure that they actually reduce the 2.8V | |
| 19 supply current draw as expected. |