# HG changeset patch
# User Mychaela Falconia <falcon@freecalypso.org>
# Date 1631750880 0
# Node ID eb68975e1b812b527ea06d8bcd21e4e1f1fa0569
# Parent  2ac10b2cde4f8c9a221b8f06115c187ad154f756
FC-handset-spec: KWH020ST23-F01 finalized

diff -r 2ac10b2cde4f -r eb68975e1b81 FC-handset-spec
--- a/FC-handset-spec	Mon Jul 19 05:01:15 2021 +0000
+++ b/FC-handset-spec	Thu Sep 16 00:08:00 2021 +0000
@@ -91,8 +91,15 @@
 
 1.4.2. Specific LCD module selection
 
-As of 2021-07, the frontrunner candidate LCD module for our FC handset is
-Formike KWH020ST23-F01.  Our selection criteria are as follows:
+Over the summer of 2021 we have selected Formike KWH020ST23-F01 as our LCD
+module for FreeCalypso; in prior years we had evaluated two other LCD modules
+from HaoRan and Startek.  All relevant datasheets (our finally chosen LCD
+module, our previous candidate LCD modules and the controller ICs inside these
+modules) are collected here:
+
+ftp://ftp.freecalypso.org/pub/embedded/LCDs/
+
+Our LCD module selection criteria were as follows:
 
 * TFT color LCD, 2.0" diagonal, 176x220 pixel resolution;
 
@@ -116,11 +123,12 @@
 MAX1916 backlight LED driver chip - see section 1.4.4.
 
 Formike KWH020ST23-F01 is an LCD module that was discovered by Mother Mychaela
-in May-June of 2021, and it appears to satisfy all of our requirements.  We have
-designed a test board for the purpose of evaluating this LCD (it will connect
-the new LCD to our Luna interface from 2020), but because of Digi-Key part
-backorder issues, the assembly of this board and thus the actual test are being
-delayed until Sep-Oct of 2021.
+in May-June of 2021, and it satisfies all of our requirements.  In June of 2021
+we received sample pieces, then we designed a test board for the purpose of
+evaluating this new LCD, connecting it to our Luna interface from 2020.  Our
+lunalcd2 test board was finally assembled in August, all tests passed, and as
+of September we are in process of ordering a larger batch of these finally
+chosen Formike LCD modules.
 
 1.4.3. Backlight and readability considerations
 
@@ -194,7 +202,7 @@
 
 1.4.4. Backlight circuit implementation
 
-In all candidate TFT LCD modules that are being considered (see section 1.4.2),
+In all candidate TFT LCD modules that have been considered (see section 1.4.2),
 the backlight consists of 3 white LEDs wired in parallel, joined either at the
 anode or at the cathode - although as we shall see momentarily, we require an
 LCD module where the 3 LEDs are joined at the anode, with the 3 cathodes brought
@@ -285,8 +293,10 @@
 will be split unequally between the two switched SET resistors, allowing a total
 of 4 different backlight intensity levels to be selected via the two Calypso
 GPIO outputs going to the 74LVC2G125 buffer's output enable inputs.  The actual
-currents will be determined some time around Sep-Oct of 2021 when we get our
-lunalcd2 test board built.
+currents will be determined after some further experimentation with our lunalcd2
+test setup: this setup features our KWH020ST23-F01 LCD, a MAX1916-based
+backlight circuit, and a DIP switch pack selecting the LED current in 1 mA
+increments.
 
 1.4.5. Slight regression relative to Pirelli DP-L10