rp2xxx: ssd1306 oled display example

[Gnyblast]

No description provided.

[mattnite]

It's important that examples are compiled so that CI catches breaks. It's okay to add a dependency to the example as it is separate from the actual package. I also see that it is your package, and that is fine, but it needs to have a compatible LICENSE, and the dependency must link to a commit with that license. If you fail to maintain that package in the future and it blocks our CI, this example can be removed.

[tact1m4n3]

You should also add the example to build.zig as well adding the module import. These are the changes you need to make:

diff --git a/examples/raspberrypi/rp2xxx/build.zig b/examples/raspberrypi/rp2xxx/build.zig
index 1add360d..8a4382ed 100644
--- a/examples/raspberrypi/rp2xxx/build.zig
+++ b/examples/raspberrypi/rp2xxx/build.zig
@@ -9,6 +9,8 @@ pub fn build(b: *std.Build) void {
     const optimize = b.standardOptimizeOption(.{});
     const maybe_example = b.option([]const u8, "example", "only build matching examples");
 
+    const font8x8_dep = b.dependency("font8x8", .{});
+
     const mz_dep = b.dependency("microzig", .{});
     const mb = MicroBuild.init(b, mz_dep) orelse return;
 
@@ -68,6 +70,9 @@ pub fn build(b: *std.Build) void {
         .{ .name = "dma", .file = "src/dma.zig" },
         .{ .name = "cyw43", .file = "src/cyw43.zig" },
         .{ .name = "mlx90640", .file = "src/mlx90640.zig" },
+        .{ .name = "ssd1306-oled", .file = "src/ssd1306_oled.zig", .imports = &.{
+            .{ .name = "font8x8", .module = font8x8_dep.module("font8x8") },
+        } },
     };
 
     var available_examples = std.ArrayList(Example).init(b.allocator);
@@ -77,12 +82,14 @@ pub fn build(b: *std.Build) void {
             .target = mb.ports.rp2xxx.boards.raspberrypi.pico,
             .name = b.fmt("pico_{s}", .{example.name}),
             .file = example.file,
+            .imports = example.imports,
         }) catch @panic("out of memory");
 
         available_examples.append(.{
             .target = mb.ports.rp2xxx.boards.raspberrypi.pico2_arm,
             .name = b.fmt("pico2_arm_{s}", .{example.name}),
             .file = example.file,
+            .imports = example.imports,
         }) catch @panic("out of memory");
 
         if (example.works_with_riscv) {
@@ -90,6 +97,7 @@ pub fn build(b: *std.Build) void {
                 .target = mb.ports.rp2xxx.boards.raspberrypi.pico2_riscv,
                 .name = b.fmt("pico2_riscv_{s}", .{example.name}),
                 .file = example.file,
+                .imports = example.imports,
             }) catch @panic("out of memory");
         }
     }
@@ -110,6 +118,7 @@ pub fn build(b: *std.Build) void {
             .target = example.target,
             .optimize = optimize,
             .root_source_file = b.path(example.file),
+            .imports = example.imports,
         });
 
         // `install_firmware()` is the MicroZig pendant to `Build.installArtifact()`
@@ -127,10 +136,12 @@ const Example = struct {
     target: *const microzig.Target,
     name: []const u8,
     file: []const u8,
+    imports: []const std.Build.Module.Import = &.{},
 };
 
 const ChipAgnosticExample = struct {
     name: []const u8,
     file: []const u8,
     works_with_riscv: bool = true,
+    imports: []const std.Build.Module.Import = &.{},
 };

To test that your example is building you should run zig build -Dexample=ssd1306-oled in the rp2xxx examples directory and check the zig-out directory.

[Grazfather]

empty_row ** 4 is probably nicer

[Grazfather]

Might be nicer to also do " " ** xxx. Makes it easy to see how wide a row is.

[Grazfather]

magic numbers? Would be nice to define these as a const for someone with a different display to more easily understand and change these values

[Grazfather]

While this is fine, it's probably overkill. You can probably just copy how the pins are configured for other i2c examples e.g. i2c_bus_scan

[Grazfather]

You sleep here but also at the top of the loop. Is this intentional?

[Grazfather]

you probably want to move this and the defer free out of the loop.

[Grazfather]

What does 64 mean here? Avoid magic numbers