shots

#!/bin/bash
#             based on joan's code:
# https://www.raspberrypi.org/forums/viewtopic.php?f=33&t=241151#p1473730
#
T=13  # trigger GPIO (Broadcom numbering), GPIO13 has hardware PWM
O=241 # off micros
S=9   # on micros (trigger)
R=5   # repeats
if [ "$4" != "" ]; then T=$4; fi
if [ "$3" != "" ]; then O=$3; fi
if [ "$2" != "" ]; then S=$2; fi
if [ "$1" != "" ]; then R=$1; fi

if [ ! -f /var/run/pigpio.pid ]; then sudo pigpiod -s 1; sleep 0.5; fi

N=/dev/null

pigs wvclr                                          # clear all wavefoms
pigs m $T w                                         # set GPIO into OUTPUT mode
pigs wvag $((1<<T)) 0 $S 0 $((1<<T)) $O >$N         # add pulse to waveform
pigs wvcre   >$N                                    # wave from pulses (1st 0)
pigs wvcha  255 0 0  255 1 $(($R%256)) $(($R/256))  # repeat trigger on/off R×