1 files changed, 100 insertions, 0 deletions
diff --git a/roles/daq-node/t/01-probe.t b/roles/daq-node/t/01-probe.t
new file mode 100644
index 0000000..8a84da3
--- /dev/null
+++ b/roles/daq-node/t/01-probe.t
@@ -0,0 +1,100 @@
+#!/usr/bin/env perl
+# -*- mode: perl-ts; -*-
+
+use strict;
+use warnings;
+
+use Test::More tests => 3;
+use Time::HiRes qw(usleep);
+
+# Basic Atlas Scientific EZO probe smoke test.
+#
+# Run on a daq-node:
+#   prove -v t/probe.t
+#
+# Optional overrides:
+#   FAPG_DAQ_SERIAL_PORT=/dev/ttyUSB1 FAPG_DAQ_SERIAL_BAUD=9600 prove -v t/probe.t
+
+my $port = $ENV{FAPG_DAQ_SERIAL_PORT} // $ARGV[0] // '/dev/ttyUSB0';
+my $baud = $ENV{FAPG_DAQ_SERIAL_BAUD} // $ARGV[1] // 9600;
+
+my $serial_module_ok = eval {
+    require Device::SerialPort;
+    Device::SerialPort->import;
+    1;
+};
+
+BAIL_OUT("Device::SerialPort is required: $@") unless $serial_module_ok;
+BAIL_OUT("Serial port does not exist: $port") unless -e $port;
+
+my $serial = Device::SerialPort->new($port)
+    or BAIL_OUT("Cannot open serial port: $port");
+
+$serial->baudrate($baud) or BAIL_OUT("Cannot set baudrate to $baud");
+$serial->databits(8)     or BAIL_OUT('Cannot set databits to 8');
+$serial->parity('none')  or BAIL_OUT('Cannot set parity to none');
+$serial->stopbits(1)     or BAIL_OUT('Cannot set stopbits to 1');
+
+$serial->read_char_time(0);
+$serial->read_const_time(100);
+
+note("Testing EZO probe on $port at $baud baud");
+
+my $info = ezo_command($serial, 'I', 500_000);
+note("I => " . printable($info));
+
+ok($info ne '', 'probe is reachable');
+like($info, qr/(?:\?I,|EZO|PH|EC|DO|ORP)/i, 'probe is identifiable');
+
+my $reading = ezo_command($serial, 'R', 1_500_000);
+note("R => " . printable($reading));
+
+like(
+    $reading,
+    qr/OK/,
+    'probe returns a single reading'
+);
+
+sub ezo_command {
+    my ($serial, $command, $wait_us) = @_;
+
+    drain_serial($serial);
+
+    my $written = $serial->write("$command\r");
+    return '' unless defined $written && $written > 0;
+
+    usleep($wait_us);
+
+    my $reply = '';
+    while (1) {
+        my ($count, $buffer) = $serial->read(255);
+        last unless $count;
+        $reply .= $buffer;
+    }
+
+    return clean_reply($reply);
+}
+
+sub drain_serial {
+    my ($serial) = @_;
+
+    while (1) {
+        my ($count, undef) = $serial->read(255);
+        last unless $count;
+    }
+}
+
+sub clean_reply {
+    my ($reply) = @_;
+
+    $reply =~ s/\r/\n/g;
+    $reply =~ s/\n+/\n/g;
+    $reply =~ s/^\n|\n$//g;
+
+    return $reply;
+}
+
+sub printable {
+    my ($value) = @_;
+    return $value eq '' ? '<no response>' : $value;
+}