1#!/bin/bash
2stty -F /dev/ttyUSB0 115200 cs8 -cstopb -parenb -icanon min 1 time 1
3
4# This script depends on the program xdotool to be installed.
5# On Debian and probably ubuntu, it can be installed with:
6# sudo apt install xdotool
7
8USB_DEV="/dev/ttyUSB0"
9JOY_BUTTON=1
10JOY_UP=1
11JOY_DOWN=1
12JOY_LEFT=1
13JOY_RIGHT=1
14
15PREV_BUTTON=1
16PREV_UP=1
17PREV_DOWN=1
18PREV_LEFT=1
19PREV_RIGHT=1
20
21KEY_BUTTON=q
22KEY_UP=w
23KEY_DOWN=s
24KEY_LEFT=a
25KEY_RIGHT=d
26
27# All input in this script is read from $USB_DEV (defined above)
28(
29while :; do
30	read LINE
31	# If we have received 5 chars in a line, it is assumed correct
32	if [ ${#LINE} = 5 ]; then
33		# Split the line up into the different directions and button
34		JOY_BUTTON=${LINE:0:1}
35		JOY_UP=${LINE:4:1}
36		JOY_DOWN=${LINE:3:1}
37		JOY_LEFT=${LINE:2:1}
38		JOY_RIGHT=${LINE:1:1}
39
40		# Only change keypress if read value is different than last time
41		if [ $JOY_BUTTON -ne $PREV_BUTTON ]; then
42			PREV_BUTTON=$JOY_BUTTON
43			if [ $JOY_BUTTON = 0 ]; then
44				xdotool keydown $KEY_BUTTON
45			else
46				xdotool keyup $KEY_BUTTON
47			fi
48		fi
49
50		if [ $JOY_UP -ne $PREV_UP ]; then
51			PREV_UP=$JOY_UP
52			if [ $JOY_UP = 0 ]; then
53				xdotool keydown $KEY_UP
54			else
55				xdotool keyup $KEY_UP
56			fi
57		fi
58
59		if [ $JOY_DOWN -ne $PREV_DOWN ]; then
60			PREV_DOWN=$JOY_DOWN
61			if [ $JOY_DOWN = 0 ]; then
62				xdotool keydown $KEY_DOWN
63			else
64				xdotool keyup $KEY_DOWN
65			fi
66		fi
67
68		if [ $JOY_LEFT -ne $PREV_LEFT ]; then
69			PREV_LEFT=$JOY_LEFT
70			if [ $JOY_LEFT = 0 ]; then
71				xdotool keydown $KEY_LEFT
72			else
73				xdotool keyup $KEY_LEFT
74			fi
75		fi
76
77		if [ $JOY_RIGHT -ne $PREV_RIGHT ]; then
78			PREV_RIGHT=$JOY_RIGHT
79			if [ $JOY_RIGHT = 0 ]; then
80				xdotool keydown $KEY_RIGHT
81			else
82				xdotool keyup $KEY_RIGHT
83			fi
84		fi
85	fi
86done
87) < $USB_DEV