Introduces support for expander PCF8575: control digital outputs (iss…

hermes-five/Cargo.toml

@@ -20,7 +20,7 @@ serde = ["dep:serde", "dep:serde_json", "dep:typetag"]
 mocks = []
 
 [dependencies]
-hermes-five-macros = { path = "../hermes-five-macros", version="0.1.0" }
+hermes-five-macros = { path = "../hermes-five-macros", version = "0.1.0" }
 dyn-clone = "1.0.19"
 futures = "0.3.31"
 log = "0.4.26"
@@ -151,6 +151,13 @@ path = "examples/servo/animate.rs"
 name = "servo_p9685"
 path = "examples/servo/pca9685.rs"
 
+# ########################################
+# EXPANDERS examples
+
+[[example]]
+name = "expanders_pcf8575"
+path = "examples/expanders/pcf8575.rs"
+
 # ########################################
 # IO examples
 

hermes-five/examples/expanders/pcf8575.rs

@@ -0,0 +1,33 @@
+//! Demonstrates how to use and control INPUT/OUTPUT devices through the PCF8575 expander.
+
+use hermes_five::devices::Led;
+use hermes_five::hardware::{Board, BoardEvent, PCF8575};
+use hermes_five::pause;
+
+#[hermes_five::runtime]
+async fn main() {
+    let board = Board::start().unwrap();
+
+    board.on(BoardEvent::OnReady, |board: Board| async move {
+        let pcf8575 = PCF8575::default(&board)?;
+
+        // Register leds for each of the 16 channels of the PCF8575.
+        let mut leds = Vec::new();
+        for i in 0..16 {
+            leds.push(Led::new_sink(&pcf8575, i, false)?);
+        }
+
+        // Create a LED chaser.
+        loop {
+            for curr in 0..16 {
+                let prev = if curr == 0 { 15 } else { curr - 1 };
+                leds[prev].turn_off()?;
+                leds[curr].turn_on()?;
+                pause!(100);
+            }
+        }
+
+        #[allow(unreachable_code)]
+        Ok(())
+    });
+}

hermes-five/examples/readme.md

@@ -48,6 +48,10 @@ The available examples are:
 - **button/pullup.rs:** Demonstrates how to use a pullup type push button input device.
 - **button/inverted.rs:** Demonstrates how to use 'inverted' push buttons.
 
+# Expanders
+
+- **expanders/pcf8575.rs:** Demonstrates how to use and control INPUT/OUTPUT devices through the PCF8575 expander.
+
 # Animation
 
 - **animation/animation.rs:** Demonstrates how to create and run a complex animation (with multiple devices, parts,
@@ -56,4 +60,5 @@ The available examples are:
 
 # Advanced
 
-- **advanced/gamepad:** Demonstrates how to use the `gilrs` crate to control your board using a gamepad (e.g., a PS4 DualShock controller).
+- **advanced/gamepad:** Demonstrates how to use the `gilrs` crate to control your board using a gamepad (e.g., a PS4
+  DualShock controller).

hermes-five/src/hardware/mod.rs

@@ -2,11 +2,13 @@
 
 mod board;
 mod pca9685;
+mod pcf8575;
 
 use crate::io::{IoProtocol, IO};
 pub use board::Board;
 pub use board::BoardEvent;
 pub use pca9685::PCA9685;
+pub use pcf8575::PCF8575;
 
 /// You most likely don't need this function (outside this crate).
 pub trait Hardware: IO {