Update ws2812 Lib and ExampleHEADmain

2 files changed, 77 insertions, 63 deletions

diff --git a/libraries/ws2812.c b/libraries/ws2812.c
index aa64031..5fbdf6c 100644
--- a/libraries/ws2812.c
+++ b/libraries/ws2812.c
@@ -1,16 +1,8 @@
+// vim: tabstop=4 shiftwidth=4 noexpandtab
 
 
 /*
-
-# WS2812 Library for libopencm3
-
-Please mind these restrictions:
-
-- Only usable with libopencm3
-- Newer versions of libopencm3 may be not compatibel (libopencm3 api is not stable yet)
-- Just usable with a clock frequency of 72 MHz
-- You have to setup the clock and gpio yourself
-
+    Documentation is in ws2812.h
 */
 
 
@@ -21,6 +13,8 @@ Please mind these restrictions:
 #define NUMBER_NOPS_SHORT 6  // 0.35 µs = 25.2 cycles @ 72 MHz = 6.3 nops --> 16.7 ns timing error
 
 
+// public API functions:
+
 void ws2812_init(WS2812_ARRAY *control_struct, uint32_t port, uint16_t pin, uint8_t *buffer_ptr, uint32_t array_length)
 {
 	control_struct->gpio_port = port;
@@ -29,47 +23,65 @@ void ws2812_init(WS2812_ARRAY *control_struct, uint32_t port, uint16_t pin, uint
 	control_struct->array_length = array_length;
 	ws2812_clear_buffer(control_struct);
 	ws2812_send_reset(control_struct);
+    ws2812_write_buffer_to_leds(control_struct);
 }
 
+void ws2812_clear_buffer(WS2812_ARRAY *control_struct)
+{
+	for (uint32_t i=0; i<(control_struct->array_length*3); i++){
+		control_struct->array_buffer[i] = 0x00;
+	}
+}
+
+void ws2812_write_buffer_to_leds(WS2812_ARRAY *control_struct)
+{
+    for (uint32_t i=0; i<(control_struct->array_length); i++)
+	{
+		ws2812_send_byte(control_struct, control_struct->array_buffer[i*3+1]);  // green first
+		ws2812_send_byte(control_struct, control_struct->array_buffer[i*3+0]);  // red second
+		ws2812_send_byte(control_struct, control_struct->array_buffer[i*3+2]);  // blue third
+	}
+    ws2812_send_reset(control_struct);
+}
+
+
+// internal functions:
 
 void ws2812_send_reset(WS2812_ARRAY *control_struct)
 {
 	gpio_clear(control_struct->gpio_port, control_struct->gpio_pin);
-	for (int i = 0; i < NUMBER_NOPS_RESET; i++) {
+	for (uint16_t i = 0; i < NUMBER_NOPS_RESET; i++) {
 		__asm__("nop");
 	}
 }
 
-
 void ws2812_send_zero(WS2812_ARRAY *control_struct)
 {
 	gpio_set(control_struct->gpio_port, control_struct->gpio_pin);
-	for (int i = 0; i < NUMBER_NOPS_SHORT; i++) {
+	for (uint8_t i = 0; i < NUMBER_NOPS_SHORT; i++) {
 		__asm__("nop");
 	}
 	gpio_clear(control_struct->gpio_port, control_struct->gpio_pin);
-	for (int i = 0; i < NUMBER_NOPS_LONG; i++) {
+	for (uint8_t i = 0; i < NUMBER_NOPS_LONG; i++) {
 		__asm__("nop");
 	}
 }
 
-
 void ws2812_send_one(WS2812_ARRAY *control_struct)
 {
 	gpio_set(control_struct->gpio_port, control_struct->gpio_pin);
-	for (int i = 0; i < NUMBER_NOPS_LONG; i++) {
+	for (uint8_t i = 0; i < NUMBER_NOPS_LONG; i++) {
 		__asm__("nop");
 	}
 	gpio_clear(control_struct->gpio_port, control_struct->gpio_pin);
-	for (int i = 0; i < NUMBER_NOPS_SHORT; i++) {
+	for (uint8_t i = 0; i < NUMBER_NOPS_SHORT; i++) {
 		__asm__("nop");
 	}
 }
 
-
 void ws2812_send_byte(WS2812_ARRAY *control_struct, uint8_t data)
 {
-	for (int i=7; i>=0; i--){
+	for (int8_t i=7; i>=0; i--){
 		if ( (data >> i) & 0x01 ){
 			ws2812_send_one(control_struct);
 		}
@@ -78,41 +90,3 @@ void ws2812_send_byte(WS2812_ARRAY *control_struct, uint8_t data)
 		}
 	}
 }
-
-
-void ws2812_send_led(WS2812_ARRAY *control_struct, uint8_t red, uint8_t green, uint8_t blue)
-{
-	ws2812_send_byte(control_struct, green);
-	ws2812_send_byte(control_struct, red);
-	ws2812_send_byte(control_struct, blue);
-}
-
-
-void ws2812_write_leds(WS2812_ARRAY *control_struct)
-{
-	for(uint32_t i=0; i<(control_struct->array_length); i++){
-		ws2812_send_led(
-			control_struct,
-			control_struct->array_buffer[i * WS2812_NUMBER_OF_COLORS + 0],  // red
-			control_struct->array_buffer[i * WS2812_NUMBER_OF_COLORS + 1],  // green
-			control_struct->array_buffer[i * WS2812_NUMBER_OF_COLORS + 2]   // blue
-		);
-	}
-	ws2812_send_reset(control_struct);
-}
-
-
-void ws2812_set_array_led(WS2812_ARRAY *control_struct, uint32_t index, uint8_t red, uint8_t green, uint8_t blue)
-{
-	control_struct->array_buffer[index * WS2812_NUMBER_OF_COLORS + 0] = red;
-	control_struct->array_buffer[index * WS2812_NUMBER_OF_COLORS + 1] = green;
-	control_struct->array_buffer[index * WS2812_NUMBER_OF_COLORS + 2] = blue;
-}
-
-
-void ws2812_clear_buffer(WS2812_ARRAY *control_struct)
-{
-	for (uint32_t i=0; i<control_struct->array_length; i++){
-		ws2812_set_array_led(control_struct, i, 0, 0, 0);
-	}
-}
diff --git a/libraries/ws2812.h b/libraries/ws2812.h
index c6c85d9..f738137 100644
--- a/libraries/ws2812.h
+++ b/libraries/ws2812.h
@@ -1,3 +1,42 @@
+// vim: tabstop=4 shiftwidth=4 noexpandtab
+
+
+/*
+	ws2812
+
+	This low-level library gives you access to ws2812 LEDs and
+	LED strips via libopencm3. Please use it like this:
+
+	- connect the data pin (DIN) of the ws2812 to a GPIO of
+	  your MCU
+	- initialize clock to a sysclock speed of 72 MHz
+	- initialize the GPIO pin with GPIO_MODE_OUTPUT_50_MHZ and
+	  GPIO_CNF_OUTPUT_PUSHPULL
+	- create a WS2812_ARRAY control struct
+	- create a uint8_t[ARRAY_LENGTH * 3] buffer
+	- call ws2812_init() with your control struct and buffer
+	- adjust values on the buffer
+	- use ws2812_write_buffer_to_leds() to set the LEDs
+
+	The uint8_t buffer has the following structure:
+
+	 -----------------------------------------------------  ...
+	|     |     |     |     |     |     |     |     |     | ...
+	|  R  |  G  |  B  |  R  |  G  |  B  |  R  |  G  |  B  | ...
+	|     |     |     |     |     |     |     |     |     | ...
+	 -----------------------------------------------------  ...
+	     first led         second led        third led      ...
+
+	Please mention that this library will never have features
+	to make fancy animations and so on. It is designed just to
+	access the LEDs on a physical layer. To avoid bad code
+	quality due to unnecessary features it will never do more
+	than this ...
+
+	Technical note: This library is based on delays. This is not
+	the best way. Maybe it will change to interrupt or DMA use in
+	the future.
+*/
 
 
 #ifndef WS2812_H
@@ -20,18 +59,19 @@ typedef struct WS2812_ARRAY{
 }WS2812_ARRAY;
 
 
+// public API functions:
+
 void ws2812_init(WS2812_ARRAY *control_struct, uint32_t port, uint16_t pin, uint8_t *buffer_ptr, uint32_t array_length);
+void ws2812_clear_buffer(WS2812_ARRAY *control_struct);
+void ws2812_write_buffer_to_leds(WS2812_ARRAY *control_struct);
+
+
+// internal functions:
 
 void ws2812_send_reset(WS2812_ARRAY *control_struct);
 void ws2812_send_zero(WS2812_ARRAY *control_struct);
 void ws2812_send_one(WS2812_ARRAY *control_struct);
-
 void ws2812_send_byte(WS2812_ARRAY *control_struct, uint8_t data);
-void ws2812_send_led(WS2812_ARRAY *control_struct, uint8_t red, uint8_t green, uint8_t blue);
-
-void ws2812_write_leds(WS2812_ARRAY *control_struct);
-void ws2812_set_array_led(WS2812_ARRAY *control_struct, uint32_t index, uint8_t red, uint8_t green, uint8_t blue);
-void ws2812_clear_buffer(WS2812_ARRAY *control_struct);
 
 
 #endif  /* WS2812_H */