narrow-alpaca-edl.sh: find which Alpaca TTL bits must be high alongside bit 5 low for EDL

narrow-alpaca-edl.sh

#!/bin/bash
# Bit 5 low alone did not give EDL, but bit 5 low with bits 0,3,4,6,7 high did.
# Find which of those must be high: drop one at a time (bit 5 stays low).
# Usage: narrow-alpaca-edl.sh <alpaca tty> <edl serial>
set -u
tty=${1:?alpaca tty}; want=${2:?edl serial}; wait_s=${WAIT_S:-5}
others="0 3 4 6 7"
stty -F "$tty" 115200 raw -echo cs8 clocal cread || exit 1
cmd() { printf '%s\r' "$*" > "$tty"; sleep 0.3; }
edl() { for d in /sys/bus/usb/devices/*; do [ -r "$d/idVendor" ] || continue
	[ "$(cat $d/idVendor)" = 05c6 ] && [ "$(cat $d/idProduct)" = 9008 ] || continue
	grep -qi "$want" "$d/serial" "$d/product" 2>/dev/null && return 0; done; return 1; }
run() {	# $1 = bits to set high (bit 5 always low)
	cmd devicePower 0; sleep 2
	for b in $others 5; do cmd ttl outputBit $b 0; done
	for b in $1; do cmd ttl outputBit $b 1; done
	cmd devicePower 1; sleep "$wait_s"
	if edl; then r=EDL; else r=no; fi
	cmd devicePower 0; sleep 1
	echo "$r"
}
cmd usbDevicePower 1
echo "all of [$others] high, 5 low: $(run "$others")"
need=
for o in $others; do
	set_=$(echo $others | tr ' ' '\n' | grep -vx "$o" | tr '\n' ' ')
	r=$(run "$set_"); echo "without $o high: $r"
	[ "$r" = no ] && need="$need $o"
done
echo "only [${need# }] high, 5 low: $(run "$need")"
for b in $others 5; do cmd ttl outputBit $b 0; done
cmd devicePower 0
echo "RESULT: EDL needs bit(s) [${need# }] high and bit 5 low"