🌴 Sync 2026-03-05 23:51:42

ssd1306/test.sh

@@ -0,0 +1,43 @@
+#!/bin/sh
+set -e
+I2C=$1
+[ -z "$I2C" ] && exit 1
+
+ROTATE=180
+# clear display every round for broken displays
+CLEAR=false
+
+LINELEN=21 # 128/6
+MAX=42 # 2 lines
+TEXT="Hello world!"
+
+
+len=`echo "$TEXT" | wc -c`
+if [ $len -gt $MAX ]; then
+	echo "Text too long (max $MAX chars)" >&2
+	exit 1
+fi
+fillround=$(( ($MAX + $len) / $len )). 
+offset=0
+
+ssd1306 -n $I2C -I 128x32
+# rotate display
+ssd1306 -n $I2C -r $ROTATE
+if $CLEAR; then
+	sleep 1
+else
+	ssd1306 -n $I2C -c
+fi
+while :; do
+	halfstart=$(($offset + $LINELEN))
+	text=""
+	for i in $(seq 0 $fillround); do
+		text="$text ${TEXT}"
+	done
+	$CLEAR && ssd1306 -n $I2C -c
+	msg="`date '+%Y-%m-%d %H:%M:%S'`"'  \n'"${text:$offset:$LINELEN}"'\n'"${text:$halfstart:$LINELEN}"'\n'"`date '+%Y-%m-%d %H:%M:%S'`  "
+	ssd1306 -n $I2C -m "$msg"
+	sleep 1
+	offset=$(( ($offset + 1) % $len ))
+done
+exit 0