config: change default control loop interval

On an unloaded rotator, this fixes the rapid relay toggling without
needing to implement debouncing.

An additional configuration validation should probably be added: the
rotator rotates in azimuth about 6 deg per second. If the control loop
speed is too slow or the controller angle tolerance is small enough,
then the controller will never be able settle (imagine that the loop
interval is 1 second. That means the rotator will move approximately 6
degrees every loop iteration, so it will always overshoot.

src/Config.zig

@@ -114,7 +114,7 @@ controller: ControllerConfig = .{
     .elevation_input = .{ .channel = .diff_23, .range = .@"5 V" },
     .azimuth_outputs = .{ .increase = .{ .io = 0 }, .decrease = .{ .io = 1 } },
     .elevation_outputs = .{ .increase = .{ .io = 2 }, .decrease = .{ .io = 3 } },
-    .loop_interval_ns = 50_000_000,
+    .loop_interval_ns = 100_000_000,
     .parking_posture = .{ .azimuth = 180, .elevation = 90 },
     .angle_tolerance = .{ .azimuth = 1, .elevation = 1 },
     .angle_offset = .{ .azimuth = 0, .elevation = 0 },

src/main.zig

@@ -12,18 +12,6 @@ fn printStderr(comptime fmt: []const u8, args: anytype) void {
     std.debug.print(fmt ++ "\n", args);
 }
 
-const commands = .{
-    .install_udev = "install-udev-rules",
-    .write_config = "write-default-config",
-    .run = "run",
-};
-
-const command_help = .{
-    .install_udev = "[udev rules.d path]: Install the built-in LabJack u12 udev rules file. May require sudo privileges. Linux only.",
-    .write_config = "[path]: write the default configuration to a json file.",
-    .run = "[config path]: run the rotctl interface with the provided config.",
-};
-
 pub fn main() !u8 {
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
     defer _ = gpa.deinit();
@@ -35,21 +23,26 @@ pub fn main() !u8 {
     };
     defer std.process.argsFree(allocator, args);
 
-    if (args.len < 2) {
-        printHelp();
+    if (args.len < 1) {
+        printStderr("No arguments at all?", .{});
         return 1;
     }
 
-    if (std.mem.eql(u8, args[1], commands.install_udev)) {
+    const exename = std.fs.path.basename(args[0]);
+
+    if (args.len < 2) {
+        printHelp(exename, .main);
+        return 1;
+    } else if (std.mem.eql(u8, args[1], commands.install_udev)) {
         if (args.len > 3) {
-            printHelp();
+            printHelp(exename, .install_udev);
             return 1;
         }
 
         return installUdevRules(if (args.len == 3) args[2] else null);
     } else if (std.mem.eql(u8, args[1], commands.write_config)) {
         if (args.len > 3) {
-            printHelp();
+            printHelp(exename, .write_config);
             return 1;
         }
 
@@ -57,7 +50,7 @@ pub fn main() !u8 {
         return writeDefaultConfig(if (args.len == 3) args[2] else null);
     } else if (std.mem.eql(u8, args[1], commands.run)) {
         if (args.len > 3) {
-            printHelp();
+            printHelp(exename, .run);
             return 1;
         }
         blk: {
@@ -85,8 +78,23 @@ pub fn main() !u8 {
         };
 
         return 0;
+    } else if (std.mem.eql(u8, args[1], commands.help)) {
+        if (args.len != 3) {
+            printHelp(exename, .help);
+            return 1;
+        }
+
+        inline for (@typeInfo(@TypeOf(commands)).Struct.fields) |field| {
+            if (std.mem.eql(u8, args[2], @field(commands, field.name))) {
+                printHelp(exename, @field(HelpTag, field.name));
+                return 0;
+            }
+        } else {
+            printHelp(exename, .help);
+            return 1;
+        }
     } else {
-        printHelp();
+        printHelp(exename, .main);
         return 1;
     }
 }
@@ -141,20 +149,135 @@ fn writeDefaultConfig(outarg: ?[]const u8) u8 {
     return 0;
 }
 
-fn printHelp() void {
-    printStderr(
-        \\Usage: yaes [command] [args...]
-        \\
-        \\  Control a Yaesu G-5500DC rotator through a LabJack U12 using the hamlib TCP interface.
-        \\
-        \\Available commands:
-        \\
-    , .{});
-
-    inline for (@typeInfo(@TypeOf(commands)).Struct.fields) |field| {
-        printStderr(
-            "  {s} {s}",
-            .{ @field(commands, field.name), @field(command_help, field.name) },
-        );
+fn printHelp(exename: []const u8, comptime cmd: HelpTag) void {
+    switch (cmd) {
+        .main => {
+            printStderr(command_help.main, .{ .exename = exename });
+            inline for (@typeInfo(@TypeOf(commands)).Struct.fields) |field| {
+                printStderr(
+                    "  {s: <" ++ max_command_len ++ "}  {s}",
+                    .{ @field(commands, field.name), @field(command_help, field.name).brief },
+                );
+            }
+            printStderr("", .{});
+        },
+        .help => {
+            printStderr(command_help.help.full, .{ .exename = exename, .cmdname = "help" });
+            inline for (@typeInfo(@TypeOf(commands)).Struct.fields) |field| {
+                printStderr(
+                    "               - {s}",
+                    .{@field(commands, field.name)},
+                );
+            }
+            printStderr("", .{});
+        },
+        else => {
+            printStderr(
+                @field(command_help, @tagName(cmd)).full,
+                .{ .exename = exename, .cmdname = @field(commands, @tagName(cmd)) },
+            );
+            printStderr("", .{});
+        },
     }
 }
+
+const HelpTag = std.meta.FieldEnum(@TypeOf(command_help));
+
+const commands = .{
+    .install_udev = "install-udev-rules",
+    .write_config = "write-default-config",
+    .run = "run",
+    .calibrate = "calibrate",
+    .help = "help",
+};
+
+const max_command_len: []const u8 = blk: {
+    var len: usize = 0;
+    for (@typeInfo(@TypeOf(commands)).Struct.fields) |field|
+        if (@field(commands, field.name).len > len) {
+            len = @field(commands, field.name).len;
+        };
+    break :blk std.fmt.comptimePrint("{d}", .{len});
+};
+
+const command_help = .{
+    .main =
+    \\Usage: {[exename]s} <command> [arguments...]
+    \\
+    \\  Calibrate/Control a Yaesu G-5500DC rotator with a LabJack U12.
+    \\
+    \\Commands:
+    ,
+    .install_udev = .{
+        .brief = "Install a udev rules file for the LabJack U12",
+        .full =
+        \\Usage: {[exename]s} {[cmdname]s} [<rules_dir>]
+        \\
+        \\  Install a udev rules file for the LabJack U12, which allows unprivileged access to the device on
+        \\  Linux-based operating systems.
+        \\
+        \\Arguments:
+        \\  rules_dir  [Optional] The path to the udev rules directory inside which the rules file will be
+        \\             written. (Default: /etc/udev/rules.d)
+        ,
+    },
+    .write_config = .{
+        .brief = "Write the default configuration to a file",
+        .full =
+        \\Usage: {[exename]s} {[cmdname]s} [<config_file>]
+        \\
+        \\  Write the built-in configuration defaults to a file. Useful as a starting point for creating a
+        \\  custom configuration.
+        \\
+        \\Arguments:
+        \\  config_file  [Optional] the path of the file to write. (Default: ./yaes.json)
+        ,
+    },
+    .run = .{
+        .brief = "Run the rotator with a hamlib-compatible TCP interface",
+        .full =
+        \\Usage: {[exename]s} {[cmdname]s} [<config_file>]
+        \\
+        \\  Expose a hamlib (rotctld)-compatible TCP interface through which the rotator can be controlled.
+        \\  This listens on localhost port 4533 by default. Only a subset of the rotctld commands are
+        \\  actually supported. A brief list of supported commands:
+        \\
+        \\    P, set_pos <az> <el> - point the rotator to the given azimuth and elevation
+        \\    p, get_pos           - return the rotator's current azimuth and elevation
+        \\    S, stop              - stop moving the rotator if it is moving
+        \\    K, park              - move the rotator to its parking posture (defined by the config)
+        \\    q, Q, quit           - [nonstandard] stop the rotator control loop and exit
+        \\
+        \\Arguments:
+        \\  config_file  [Optional] the name of the config file to load. If this file does not exist, then
+        \\               the built-in defaults will be used. (Default: ./yaes.json)
+        ,
+    },
+    .calibrate = .{
+        .brief = "Calibrate the rotator's feedback or its orientation to geodetic North",
+        .full =
+        \\Usage: {[exename]s} {[cmdname]s} <routine> [<config_file>]
+        \\
+        \\  Perform a calibration routine and write an updated configuration with its results.
+        \\
+        \\Arguments:
+        \\  routine      Must be one of `feedback` or `orientation`. The different calibration routines have
+        \\               different requirements. `orientation` calibration is a sun-pointing-based routine and
+        \\               should be performed after `feedback` calibration is complete.
+        \\  config_file  [Optional] the path of a config file to load. This file will be updated with the
+        \\               results of the calibration process. If omitted and the configuration file does not
+        \\               exist, then the default configuration will be used. (Default: ./yaes.json)
+        ,
+    },
+    .help = .{
+        .brief = "Print detailed help for a given command",
+        .full =
+        \\Usage: {[exename]s} {[cmdname]s} <command>
+        \\
+        \\  Print information on how to use a command and exit.
+        \\
+        \\Arguments:
+        \\  command   The name of the command to print information about. Must be one of the following:
+        ,
+    },
+};