add ability to switch HDMI displays with scheduler

Change-type: minor

Author: escoand

scheduler/Dockerfile

@@ -3,4 +3,28 @@ FROM balenalib/raspberrypi3-alpine
 COPY scripts /usr/src/
 RUN chmod +x /usr/src/*.sh
 
+RUN apk --no-cache add raspberrypi raspberrypi-libs raspberrypi-dev alpine-sdk \
+                       eudev-dev python3-dev libxrandr-dev swig \
+                       p8-platform-dev cmake && \
+     adduser -S builder -G abuild
+
+USER builder
+
+RUN cd && \
+    wget https://git.alpinelinux.org/aports/plain/community/libcec/APKBUILD && \
+    sed -i \
+      -e '23a-DRPI_INCLUDE_DIR=/opt/vc/include \\' \
+      -e '23a-DRPI_LIB_DIR=/opt/vc/lib \\' \
+    APKBUILD && \
+    abuild-keygen -a -i && \
+    abuild
+
+USER root
+
+RUN apk --allow-untrusted --no-cache add \
+            /home/builder/packages/home/*/libcec-4*.apk && \
+    deluser --remove-home builder && \
+    apk del raspberrypi-dev alpine-sdk eudev-dev python3-dev libxrandr-dev \
+            swig p8-platform-dev cmake
+
 CMD /usr/src/start.sh

scheduler/scripts/backlight_off.sh

@@ -1,2 +1,12 @@
 #!/bin/bash
-echo -n 1 > /sys/class/backlight/rpi_backlight/bl_power
+
+export PATH="$PATH:/opt/vc/bin/"
+export LD_LIBRARY_PATH="/opt/vc/lib/"
+
+output=$(tvservice -s)
+
+if [[ $output =~ "0x400000 [LCD]" ]]; then
+  echo -n 1 > /sys/class/backlight/rpi_backlight/bl_power
+else
+  echo standby 0 | cec-client -d 1 -s
+fi

scheduler/scripts/backlight_on.sh

@@ -1,2 +1,12 @@
 #!/bin/bash
-echo -n 0 > /sys/class/backlight/rpi_backlight/bl_power
+
+export PATH="$PATH:/opt/vc/bin/"
+export LD_LIBRARY_PATH="/opt/vc/lib/"
+
+output=$(tvservice -s)
+
+if [[ $output =~ "0x400000 [LCD]" ]]; then
+  echo -n 0 > /sys/class/backlight/rpi_backlight/bl_power
+else
+  echo as 0 | cec-client -d 1 -s
+fi

scheduler/scripts/start.sh

@@ -1,8 +1,12 @@
 #!/bin/bash
+
 if [ ! -z ${ENABLE_BACKLIGHT_TIMER+x} ] && [ "$ENABLE_BACKLIGHT_TIMER" -eq "1" ]
 then
-  (crontab -l; echo "${BACKLIGHT_ON:-0 8 * * *} /usr/src/backlight_on.sh") | crontab -
-  (crontab -l; echo "${BACKLIGHT_OFF:-0 23 * * *} /usr/src/backlight_off.sh") | crontab -
+  (
+    crontab -l
+    echo "${BACKLIGHT_ON:-0 8 * * *} /usr/src/backlight_on.sh"
+    echo "${BACKLIGHT_OFF:-0 23 * * *} /usr/src/backlight_off.sh"
+  ) | crontab -
 fi
 
 crond -f