Package: lcd4linux
Version: 0.11.0~svn1203-1
Severity: important
Tags: patch
Dear Maintainer,
Using driver 'picoLCDGraphic' in lcd4linux.conf, backlight can only be set to 0
or 1 (off/on).
While the backlight of the picolcd is on at boot, the moment lcd4linux starts,
the backlight turns
off with either setting.
Looking at the source for the driver, I found that somewhere along the line,
the function to
set the backlight had been changed to use an 8 bit value from 0 - 255,
effectively making this
a brightness setting:
static int drv_pLG_backlight(int backlight)
{
unsigned char cmd[2] = { 0x91 };/* set backlight */
if (backlight < 0)
backlight = 0;
if (backlight > 255)
backlight = 255;
cmd[1] = backlight;
drv_pLG_send(cmd, 2);
return backlight;
}
... but the config option for backlight was still limited to only accepting a 0
or 1:
if (cfg_number(section, "Backlight", 0, 0, 1, &value) > 0) {
info("Setting backlight to %d", value);
drv_pLG_backlight(value);
}
I've patched that if statement above to accept values between 0 and 255. Now,
setting the config
option for backlight to 255 in lcd4linux.conf does result in the backlight
being turned on at
full brightness.
-- System Information:
Debian Release: 9.0
APT prefers testing
APT policy: (500, 'testing')
Architecture: amd64
(x86_64)
Kernel: Linux 4.9.0-2-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
Versions of packages lcd4linux depends on:
ii init-system-helpers 1.47
ii libc62.24-10
ii libdbus-1-3 1.10.18-1
ii libftdi1 0.20-4
ii libgd3 2.2.4-2
ii libjpeg62-turbo 1:1.5.1-2
ii libmariadbclient18 10.1.22-3
ii libmpdclient22.9-1
ii libncurses5 6.0+20161126-1
ii libpython2.7 2.7.13-2
ii libsqlite3-0 3.16.2-3
ii libtinfo56.0+20161126-1
ii libusb-0.1-4 2:0.1.12-30
ii libvncserver10.9.11+dfsg-1
ii libx11-6 2:1.6.4-3
ii lsb-base 9.20161125
lcd4linux recommends no packages.
lcd4linux suggests no packages.
-- Configuration Files:
/etc/lcd4linux.conf [Errno 13] Permission denied: '/etc/lcd4linux.conf'
Relevant lines from lcd4linux.conf:
Display picoLCD {
Driver 'picoLCDGraphic'
Size '256x64'
#Contrast 230
Contrast 235
Backlight 255
Brightness 100
Inverted 0
Icons 1
}
-- no debconf information
diff --git a/drv_picoLCDGraphic.c b/drv_picoLCDGraphic.c
index 244cc5b..3f2e957 100644
--- a/drv_picoLCDGraphic.c
+++ b/drv_picoLCDGraphic.c
@@ -539,7 +539,7 @@ static int drv_pLG_start(const char *section, const int
quiet)
drv_pLG_contrast(value);
}
-if (cfg_number(section, "Backlight", 0, 0, 1, &value) > 0) {
+if (cfg_number(section, "Backlight", 0, 0, 255, &value) > 0) {
info("Setting backlight to %d", value);
drv_pLG_backlight(value);
}
