From 4eb6c240405c25ff8255aa5eb0076e7245532e9d Mon Sep 17 00:00:00 2001
From: Tomas Mudrunka <tomas.mudrunka@gmail.com>
Date: Wed, 3 Jan 2024 17:51:46 +0100
Subject: [PATCH] Lepsi tester seriovky

---
 bash/serial_loopback_test.sh | 62 ++++++++++++++++++++++++++++--------
 1 file changed, 49 insertions(+), 13 deletions(-)
 mode change 100644 => 100755 bash/serial_loopback_test.sh

diff --git a/bash/serial_loopback_test.sh b/bash/serial_loopback_test.sh
old mode 100644
new mode 100755
index 6e24309..f160b2d
--- a/bash/serial_loopback_test.sh
+++ b/bash/serial_loopback_test.sh
@@ -1,35 +1,71 @@
-#!/bin/bash
-#(c) Tomas Mudrunka 2022
+#!/bin/sh
+#Serial line tester, should work in busybox ash
+#(c) Tomas Mudrunka 2022-2024
 
-[ -z "$1" ] && {
-	echo "Usage: $0 /dev/ttyTX [/dev/ttyRX]"
-	exit 1
-}
+trylimit=0
+seconds=0
+baudrate=115200
+workaround_rs485=false
+
+while getopts ":t:r:b:l:s:w" OPT; do
+	#echo "$OPT ==> $OPTARG";
+	case $OPT in
+		t) port_tx=$OPTARG;;
+		r) port_rx=$OPTARG;;
+		b) baudrate=$OPTARG;;
+		l) trylimit=$OPTARG;;
+		s) seconds=$OPTARG;;
+		w) workaround_rs485=true;;
+
+		'?') echo "Usage: $0 -t /dev/ttyTX [-r /dev/ttyRX] [-b 9600] [-l 10] [-s 10] [-w]"	>&2; exit 250;;
+		':') echo "Missing option argument for -$OPTARG"					>&2; exit 251;;
+		*  ) echo "Unimplemented option: -$OPT"							>&2; exit 252;;
+	esac
+done
+
+[ -z "$port_tx" ] && port_tx="$port_rx"
+[ -z "$port_rx" ] && port_rx="$port_tx"
+[ -z "$port_rx" ] && { echo Port not specified; exit 253; }
 
-port_tx="${1:-/dev/ttyUSB0}"
-port_rx="${2:-$port_tx}"
 
 testdata="${RANDOM}d82b2ae45432e7c80699852ab557b279c42180a379711aae85487bda0cc58602f65c0ab5af0d510d6ac1606c52f887f3332052f67c45212dbbf2730${RANDOM}"
 
-echo "Running loopback test on $port_tx -> $port_rx"
+echo "Running $baudrate baud loopback test on $port_tx -> $port_rx"
+echo "Limiting to $trylimit iterations and $seconds seconds (0 = no limit)"
 
-stty -F "$port_tx" raw -echo
-stty -F "$port_rx" raw -echo
+stty -F "$port_tx" raw -echo "$baudrate"
+stty -F "$port_rx" raw -echo "$baudrate"
 
 exec 5>"$port_tx"
 exec 6<"$port_rx"
 
+$workaround_rs485 && {
+	echo "Deasserting RTS on buggy RS485 drivers by writing to RX port"
+	echo>"$port_rx"
+	read -rst 1 -u 6
+}
+
 errcnt=0
+trycnt=0
+datestart="$(date +%s)"
+dateend="$(($datestart+$seconds))"
 while true; do
 	echo "$testdata" >&5
 	unset line
 	read -rst 1 -u 6 line
 	#echo "LINE: $line"
 	[ "$line" != "$testdata" ] && {
-		((errcnt=errcnt+1))
 		echo -e "$(date +'%D %T')\t$errcnt\tError receiving data $port_tx -> $port_rx"
-	}
+	} && errcnt=$((errcnt+1))
+	trycnt=$((trycnt+1))
+	#echo "try $trycnt err $errcnt lim $trylimit"
+	[ $trylimit -gt 0 -a $trycnt -gt $trylimit ] && break
+	[ $seconds -gt 0 ] && [ $(date +%s) -gt $dateend ] && break
 done
 
 exec 5>&-
 exec 6<&-
+
+echo TRANSMITTED: $trycnt, ERRORS: $errcnt, SECONDS: $(($(date +%s)-$datestart))
+[ "$errcnt" = "0" -a "$trycnt" -gt 0 ] && exit 0
+exit 255
-- 
2.30.2