Add a slow feature

Author: david-sawatzke

Cargo.toml

@@ -8,6 +8,9 @@ edition = "2018"
 nb = "0.1.1"
 smart-leds-trait = {git = "https://github.com/smart-leds-rs/smart-leds-trait"}
 
+[features]
+slow = []
+
 [dependencies.embedded-hal]
 features = ["unproven"]
 version = "0.2.1"

README.md

@@ -0,0 +1,6 @@
+# Ws2812 lib with timer based delays
+
+If your timer/micro is to slow (e.g. all leds are white), you may wish to enable
+the `slow` feature. It will remove any delay for the high part of the zero bits.
+This may be too short for some led strips, which may display wrong data. In that
+case, you might want to clock higher or use another driver.

src/lib.rs

@@ -25,6 +25,28 @@ where
         Self { timer, pin }
     }
     /// Write a single color for ws2812 devices
+    #[cfg(feature = "slow")]
+    fn write_color(&mut self, data: Color) {
+        let mut serial_bits = (data.g as u32) << 16 | (data.r as u32) << 8 | (data.b as u32) << 0;
+        for _ in 0..24 {
+            if (serial_bits & 0x00800000) != 0 {
+                block!(self.timer.wait()).ok();
+                self.pin.set_high();
+                block!(self.timer.wait()).ok();
+                block!(self.timer.wait()).ok();
+                self.pin.set_low();
+            } else {
+                block!(self.timer.wait()).ok();
+                self.pin.set_high();
+                self.pin.set_low();
+                block!(self.timer.wait()).ok();
+                block!(self.timer.wait()).ok();
+            }
+            serial_bits <<= 1;
+        }
+    }
+
+    #[cfg(not(feature = "slow"))]
     fn write_color(&mut self, data: Color) {
         let mut serial_bits = (data.g as u32) << 16 | (data.r as u32) << 8 | (data.b as u32) << 0;
         for _ in 0..24 {