| 1 | #!/bin/sh |
| 2 | # |
| 3 | #Serial line tester v0.3 |
| 4 | #(c) Tomas Mudrunka 2022-2024 |
| 5 | # |
| 6 | #Tested in: busybox ash, bash |
| 7 | |
| 8 | function serial_loopback_test() { |
| 9 | |
| 10 | port_tx= |
| 11 | port_rx= |
| 12 | trylimit=0 |
| 13 | seconds=0 |
| 14 | baudrate=115200 |
| 15 | workaround_rs485=false |
| 16 | |
| 17 | while getopts ":t:r:b:l:s:w" OPT; do |
| 18 | #echo "$OPT ==> $OPTARG"; |
| 19 | case $OPT in |
| 20 | t) port_tx=$OPTARG;; |
| 21 | r) port_rx=$OPTARG;; |
| 22 | b) baudrate=$OPTARG;; |
| 23 | l) trylimit=$OPTARG;; |
| 24 | s) seconds=$OPTARG;; |
| 25 | w) workaround_rs485=true;; |
| 26 | |
| 27 | '?') echo "Usage: $0 -t /dev/ttyTX [-r /dev/ttyRX] [-b 9600] [-l 10] [-s 10] [-w]" >&2; return 250;; |
| 28 | ':') echo "Missing option argument for -$OPTARG" >&2; return 251;; |
| 29 | * ) echo "Unimplemented option: -$OPT" >&2; return 252;; |
| 30 | esac |
| 31 | done |
| 32 | |
| 33 | [ -z "$port_tx" ] && port_tx="$port_rx" |
| 34 | [ -z "$port_rx" ] && port_rx="$port_tx" |
| 35 | [ -z "$port_rx" ] && { echo Port not specified; return 253; } |
| 36 | |
| 37 | |
| 38 | testdata="${RANDOM}d82b2ae45432e7c80699852ab557b279c42180a379711aae85487bda0cc58602f65c0ab5af0d510d6ac1606c52f887f3332052f67c45212dbbf2730${RANDOM}" |
| 39 | |
| 40 | echo "Running $baudrate baud loopback test on $port_tx -> $port_rx" |
| 41 | echo "Limiting to $trylimit iterations and $seconds seconds (0 = no limit)" |
| 42 | |
| 43 | stty -F "$port_tx" raw -echo "$baudrate" |
| 44 | stty -F "$port_rx" raw -echo "$baudrate" |
| 45 | |
| 46 | exec 5>"$port_tx" |
| 47 | exec 6<"$port_rx" |
| 48 | |
| 49 | $workaround_rs485 && { |
| 50 | echo "Deasserting RTS on buggy RS485 drivers by writing to RX port" |
| 51 | echo>"$port_rx" |
| 52 | read -rst 1 -u 6 |
| 53 | } |
| 54 | |
| 55 | errcnt=0 |
| 56 | trycnt=0 |
| 57 | datestart="$(date +%s)" |
| 58 | dateend="$(($datestart+$seconds))" |
| 59 | while true; do |
| 60 | echo "$testdata" >&5 |
| 61 | unset line |
| 62 | read -rst 1 -u 6 line |
| 63 | #echo "LINE: $line" |
| 64 | [ "$line" != "$testdata" ] && errcnt=$((errcnt+1)) && |
| 65 | echo -e "$(date +'%D %T')\t$errcnt\tError receiving data $port_tx -> $port_rx" |
| 66 | trycnt=$((trycnt+1)) |
| 67 | #echo "try $trycnt err $errcnt lim $trylimit" |
| 68 | [ $trylimit -gt 0 -a $trycnt -gt $trylimit ] && break |
| 69 | [ $seconds -gt 0 ] && [ $(date +%s) -gt $dateend ] && break |
| 70 | done |
| 71 | |
| 72 | exec 5>&- |
| 73 | exec 6<&- |
| 74 | |
| 75 | echo TRANSMITTED: $trycnt, ERRORS: $errcnt, SECONDS: $(($(date +%s)-$datestart)) |
| 76 | [ "$errcnt" = "0" -a "$trycnt" -gt 0 ] && return 0 |
| 77 | return 255 |
| 78 | |
| 79 | } |
| 80 | |
| 81 | serial_loopback_test "$@" |