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authorJoel Challis <git@zvecr.com>2021-11-25 19:35:06 +0000
committerGitHub <noreply@github.com>2021-11-25 19:35:06 +0000
commit5e9c29da0df045b03ada9278c34f37b22349a6f7 (patch)
tree3dbe67afa346513de1132e23c636b5ad01bc3550 /drivers
parent3d0062071133ad76504ede49a66063115c4a06c5 (diff)
Tidy up adjustable ws2812 timing (#15299)
Diffstat (limited to 'drivers')
-rw-r--r--drivers/ws2812.h32
1 files changed, 31 insertions, 1 deletions
diff --git a/drivers/ws2812.h b/drivers/ws2812.h
index f179fcb0ef..945b3d0728 100644
--- a/drivers/ws2812.h
+++ b/drivers/ws2812.h
@@ -18,10 +18,40 @@
#include "quantum/color.h"
/*
+ * The WS2812 datasheets define T1H 900ns, T0H 350ns, T1L 350ns, T0L 900ns. Hence, by default, these
+ * are chosen to be conservative and avoid problems rather than for maximum throughput; in the code,
+ * this is done by default using a WS2812_TIMING parameter that accounts for the whole window (1250ns)
+ * and defining T1H and T0H; T1L and T0L are obtained by subtracting their low counterparts from the window.
+ *
+ * However, there are certain "WS2812"-like LEDs, like the SK6812s, which work in a similar
+ * communication topology but use different timings for the window and the T1L, T1H, T0L and T0H.
+ * This means that, albeit the same driver being applicable, the timings must be adapted.
+ */
+
+#ifndef WS2812_TIMING
+# define WS2812_TIMING 1250
+#endif
+
+#ifndef WS2812_T1H
+# define WS2812_T1H 900 // Width of a 1 bit in ns
+#endif
+
+#ifndef WS2812_T1L
+# define WS2812_T1L (WS2812_TIMING - WS2812_T1H) // Width of a 1 bit in ns
+#endif
+
+#ifndef WS2812_T0H
+# define WS2812_T0H 350 // Width of a 0 bit in ns
+#endif
+
+#ifndef WS2812_T0L
+# define WS2812_T0L (WS2812_TIMING - WS2812_T0H) // Width of a 0 bit in ns
+#endif
+
+/*
* Older WS2812s can handle a reset time (TRST) of 50us, but recent
* component revisions require a minimum of 280us.
*/
-
#if !defined(WS2812_TRST_US)
# define WS2812_TRST_US 280
#endif